This article contends that the environmental release of genetically engineered (GE) animals with heritable traits that are patented will present a challenge to the efforts of nations and indigenous peoples to engage in self‐determination. The environmental release of such animals has been proposed on the grounds that they could function as public health tools or as solutions to the problem of agricultural insect pests. This article brings into focus two political‐economic‐legal problems that would arise with the (...) environmental release of such organisms. To address those challenges, it is proposed that nations considering the environmental release of GE animals must take into account the underlying circumstances and policy failures that motivate arguments for the use of the modified animals. Moreover, countries must recognize that the UN International Covenant on Civil and Political Rights and the UN International Covenant on Economic, Social and Cultural Rights place on them an obligation to ensure that GE animals with patented heritable traits are not released without the substantive consent of the nations or indigenous peoples that could be affected. (shrink)

The paper argues that we should not genetically engineer hogs to suit the preferences of farmers and consumers.

What makes humans different from other animals, what humans are entitled to do to other species, whether time travel is possible, what limits should be placed on science and technology, the morality and practicality of genetic engineering—these are just some of the philosophical problems raised by Planet of the Apes. Planet of the Apes and Philosophy looks at all the deeper issues involved in the Planet of the Apes stories. It covers the entire franchise, from Pierre Boulle’s 1963 novel (...) Monkey Planet to the successful 2012 reboot Rise of the Planet of the Apes. The chapters reflect diverse points of view, philosophical, religious, and scientific. The ethical relations of humans with animals are explored in several chapters, with entertaining and incisive observations on animal intelligence, animal rights, and human-animal interaction. Genetic engineering is changing humans, animals, and plants, raising new questions about the morality of such interventions. The scientific recognition that humans and chimps share 99 percent of their genes makes a future in which non-human animals acquire greater importance a distinct possibility. Planet of the Apes is the most resonant of all scientific apocalypse myths. (shrink)

Forty years’ experience as a bacterial geneticist has taught me that bacteria possess many cognitive, computational and evolutionary capabilities unimaginable in the first six decades of the twentieth century. Analysis of cellular processes such as metabolism, regulation of protein synthesis, and DNA repair established that bacteria continually monitor their external and internal environments and compute functional outputs based on information provided by their sensory apparatus. Studies of genetic recombination, lysogeny, antibiotic resistance and my own work on transposable elements revealed multiple (...) widespread bacterial systems for mobilizing and engineering DNA molecules. Examination of colony development and organization led me to appreciate how extensive multicellular collaboration is among the majority of bacterial species. Contemporary research in many laboratories on cell–cell signaling, symbiosis and pathogenesis show that bacteria utilise sophisticated mechanisms for intercellular communication and even have the ability to commandeer the basic cell biology of ‘higher’ plants and animals to meet their own needs. This remarkable series of observations requires us to revise basic ideas about biological information processing and recognise that even the smallest cells are sentient beings. Previous article in issue. (shrink)

The primary responsibility of the US Food and Drug Administration is to protect public health by ensuring the safety of the food supply. To that end, it sometimes conducts risk assessments of novel food products, such as genetically modified food. The FDA describes its regulatory review of GM food as a purely scientific activity, untainted by any normative considerations. This paper provides evidence that the regulatory agency is not justified in making that claim. It is argued that the FDA’s (...) policy stance on GM food is shaped by neoliberal considerations. The agency’s review of a genetically engineered animal, the AquAdvantage salmon, is used as a case study to track the influence of neoliberalism on its regulatory review protocol. After that, an epistemic argument justifying public engagement in the risk assessment of new GM food is outlined. It is because risk evaluations involve normative judgments, in a democracy, layperson representatives of informal epistemic communities that could be affected by a new GM food should have the opportunity to decide the ethical, political or other normative questions that arise during the regulatory review of that entity. (shrink)

In this article, the difference between human and animal in philosophy is mainly handled. This difference is thought over the concept of “the other” and Heidegger’s phenomenological distinction between human and animal. With respect to especially the views of Derrida and Levinas regarding to this matter, it has been attempted to exhibit this difference. Therefore, the two approaches -which were represented as the opposition of Derrida and Levinas- have been tried to clarify. After this, as a new approach to this (...) opposition, the concept of “embrace” is philosophically problematized. This examination which also can be read under the main heading of philosophy of body makes especially the dorsal and more generally the whole back surface of human body subject matter of philosophical interpretation. The concepts of dorsal and embracing which can also be considered from the angle of phenomenology of the body- are approached from evolutionary and psychologically. With this, the concept of embracing deepens the thought of being-together-with-others in a specific context. A special relation is constructed between the meaning that is giving to embracing and rubbing of the back and existing. (shrink)

In recent years, humans’ ability to selectively modify genes has increased dramatically as a result of the development of new, more efficient, and easier genetic modification technology. In this paper, we argue in favor of using this technology to improve the welfare of agricultural animals. We first argue that using animals genetically modified for improved welfare is preferable to the current status quo. Nevertheless, the strongest argument against pursuing gene editing for welfare is that there are alternative (...) approaches to addressing some of the challenges of modern agriculture that may offer ethical advantages over genetic modification; namely, a dramatic shift towards plant-based diets or the development of in vitro meat. Nevertheless, we provide reasons for thinking that despite these possible comparative disadvantages there are important reasons for continuing the pursuit of welfare improvements via genetic modification. (shrink)

In recent years, some ethicists have defended that we should genetically engineer farmed animals to diminish or eliminate their capacity to experience negative affective states, a process known as disenhancement that would, according to these authors, result in a situation that is better than the status quo. While we agree with this overall assessment, we believe that it is a mistake to defend disenhancement as a good solution to farmed animals’ plight. This is because disenhancement entails some (...) generally unseen harms that arise from the fact that negative affective states, despite feeling bad, support the access to a number of intrinsic goods, such as individuality, social relationships, meaning, and political participation. Though farmed animals currently have few opportunities to enjoy these goods, we argue that this is a reason to change the environment in which they are kept, not the animals. If we truly care about improving farmed animals’ lives, we should aim to enrich their environment, rather than impoverish their mental lives. (shrink)

Within this paper, I critique the history of the modification of the broiler chicken through selective breeding and possible future genetic modification. I utilize Margaret Atwood’s fictitious depiction of genetically engineered chickens, from her novel Oryx and Crake , in order to forward the argument that modifications that eliminate animal telos either move beyond the range of current ethical frameworks or can be ethically defended by them. I then utilize the work of feminist epistemologists to argue that understanding (...) what it means to be a chicken shapes our conceptions of what modifications are or are not acceptable. Taking into account justifications stemming from practical knowledge when making ontological claims can help to shift our understanding of what animal modifications can or cannot be justified. The paper ends by addressing three possible problems brought about by accepting such justifications. (shrink)

Genetically engineered (GE) insects, such as the GE OX513A Aedes aegypti mosquitoes, have been designed to suppress their wild-type populations so as to reduce the transmission of vector-borne diseases in humans. Apart from the ecological and epidemiological uncertainties associated with this approach, such biotechnological approaches may be used by individual governments or the global community of nations to avoid addressing the underlying structural, systemic causes of those infections... We discuss here key ethical questions raised by the use of (...) GE mosquitoes, with the aim of fostering discussion between the public, researchers, policy makers, healthcare organizations, and regulatory agencies at the local, national, and international levels. We affect that goal by outlining a procedural approach to decision-making about the use of the “biotechnology” that goes beyond “community engagement.” The protocol we advocate for entails informed deliberations and decision-making at the community level. It is designed to ensure that the voices of the marginalized and vulnerable groups that would be disproportionately affected by the decision are heard during the community-wide discussions. Moreover, we make the case that the values embedded in the risk assessment should be identified so that the community can make an informed decision about the use of GE insects. In addition, we advocate for the involvement of a variety of actors whose responsibility would be to ensure that the community has the opportunity to make an informed decision based on deliberations about the use of the “biotechnology.”. (shrink)

Genetic engineering technologies are a subclass of the biotechnology family, and are concerned with the use of laboratory-based technologies to intervene with a given organism at the genetic level, i.e., the level of its DNA. This class of technologies could feasibly be used to treat diseases and disabilities, create disease-resistant crops, or even be used to enhance humans to make them more resistant to certain environmental conditions. However, both therapeutic and enhancement applications of genetic engineering raise serious ethical concerns. This (...) paper examines various objections to genetic engineering (as applied to humans) which have been raised in the literature, and presents a new way to frame these issues, and to look for solutions. Specifically, this paper frames genetic engineering technologies within the ‘design turn in applied ethics’ lens and thus situates these technologies as covarying with societal forces. The value sensitive design (VSD) approach to technology design is then appropriated as the conceptual framework in which genetic engineering technologies can be considered so that they can be designed for important human values. By doing so, this paper brings further nuance to the scholarship on genetic engineering technologies by discussing the sociotechnicity of genetic engineering systems rather than framing them as value-neutral tools that either support or constrain values based on how they are used. (shrink)

In my essay I consider the imaginary case of a future mother who refuses to undergo genetic alteration on her germline although she knows that her, as yet unconceived, child will have a serious genetic disorder. I analyze the good and bad points of two branches of arguments directed against her decision, consequentialist and rights-based. Then I discuss whether accepting one line of these arguments or the other makes a difference in moral assessment. I conclude that, although from the preanalytical (...) perspective we strongly oppose the refusal of genetic treatment in my imaginary case, it is probably impossible to construct one coherent theory which embraces all possible moral dilemmas triggered by our actions which affect the number and the identity of future people. (shrink)

Though the vegetarian movement sparked by Peter Singer’s book Animal Liberation has achieved some success, there is more animal suffering caused today due to factory farming than there was when the book was originally written. In this paper, I argue that there may be a technological solution to the problem of animal suffering in intensive factory farming operations. In particular, I suggest that recent research indicates that we may be very close to, if not already at, the point where we (...) can genetically engineer factory-farmed livestock with a reduced or completely eliminated capacity to suffer. In as much as animal suffering is the principal concern that motivates the animal welfare movement, this development should be of central interest to its adherents. Moreover, I will argue that all people concerned with animal welfare should agree that we ought to replace the animals currently used in factory farming with animals whose ability to suffer is diminished if we are able to do so. (shrink)

In recent years, genetically engineered (GE) mosquitoes have been proposed as a public health measure against the high incidence of mosquito-borne diseases among the poor in regions of the global South. While uncertainties as well as risks for humans and ecosystems are entailed by the open-release of GE mosquitoes, a powerful global health governance non-state organization is funding the development of and advocating the use of those bio-technologies as public health tools. In August 2016, the US Food and (...) Drug Agency (FDA) approved the uncaged field trial of a GE Aedes aegypti mosquito in Key Haven, Florida. The FDA’s decision was based on its assessment of the risks of the proposed experimental public health research project. The FDA is considered a global regulatory standard setter. So, its approval of the uncaged field trial could be used by proponents of GE mosquitoes to urge countries in the global South to permit the use of those bio-technologies. -/- From a public health ethics perspective, this paper evaluates the FDA’s 2016 risk assessment of the proposed uncaged field trial of the GE mosquito to determine whether it qualified as a realistic risk evaluation. -/- The FDA’s risk assessment of the proposed uncaged field trial did not proximate the conditions under which the GE mosquitoes would be used in regions of the global South where there is a high prevalence of mosquito-borne diseases. -/- Given that health and disease have political-economic determinants, whether a risk assessment of a product is realistic or not particularly matters with respect to interventions meant for public health problems that disproportionately impact socio-economically marginalized populations. If ineffective public health interventions are adopted based on risk evaluations that do not closely mirror the conditions under which those products would actually be used, there could be public health and ethical costs for those populations. (shrink)

Imagine a world where everyone is healthy, intelligent, long living and happy. Intuitively this seems wonderful, albeit unrealistic. However, recent scientific developments in genetic engineering, namely CRISPR/Cas bring the question into public discourse, how the genetic enhancement of humans should be evaluated morally.

This paper sets out to defend human genetic engineering with a new bioethical approach, post-humanism, combined with a radical democratic political framework. Arguments for the restriction of human genetic engineering, and specifically germ-line enhancement, are reviewed. Arguments are divided into those which are fundamental matters of faith, or "bio-Luddite" arguments, and those which can be addressed through public policy, or "gene-angst" arguments.The four bio-Luddite concerns addressed are: Medicine Makes People Sick; There are Sacred Limits of the Natural Order; Technologies Always (...) Serve Ruling Interests; The Genome is Too Complicated to Engineer. I argue that these are matters of faith that one either accepts or rejects, and that I reject.The non-fundamentalist or pragmatic concerns I discuss are: Fascist Applications; The Value of Genetic Diversity; The Geneticization of Life; Genetic Discrimination and Confidentiality; Systematically Bad Decisions by Parents; Discrimination Against the Disabled; Unequal Access; The Decline of Social Solidarity. I conclude that all these concerns can be adequately addressed through a proactive regulative framework administered by a liberal democratic state. Therefore, even germ-line genetic enhancement should eventually made available since the potential benefits greatly outweigh the potential risks. (shrink)

When this article was first planned, writing was going to be exclusively about two things - the origin of life and human evolution. But it turned out to be out of the question for the author to restrict himself to these biological and anthropological topics. A proper understanding of them required answering questions like “What is the nature of the universe – the home of life – and how did it originate?”, “How can time travel be removed from fantasy and (...) science fiction, to be made scientific and practical?”, and “How can the proposed young age of genus Homo be made to actually be reasonable – when simply stating it would be solid ground for instant rejection and dismissal?” The result is that the article also talks about subjects like Artificial Intelligence, General Relativity, and cosmology. -/- From where did life originate? God? Evolution? Panspermia? If the tendency of humans and scientists to regard undiscovered science as pseudoscience can be overcome, Einstein gave another alternative to consider when he introduced General Relativity. Time isn’t linear – progressing in a straight line from past to present to future. That assumption ignores Relativity which states that space AND TIME are curved. Where did life and the genetic code come from? Can the answer build AI? -/- The first question can be answered by the section of this article titled SETI, Evolution, and Time which says life (possibly multicellular and intelligent) and the genetic code came from humans acquiring knowledge of these things over the centuries, then applying that knowledge – via terraforming, accumulation of raw materials like amino acids and nucleic acids, genetic engineering - to a time in the past when life didn’t exist. From that origin, life evolved through innumerable mutations and adaptations, with humans once again acquiring knowledge of it in cyclic (nonlinear) time. -/- The second question is answered by saying artificial intelligence (AI) as the product of life is only half of the equation. The other half refers to Relativity’s curved space-time and violation of the notion that time always travels from past to future. We have always lived in an artificially intelligent, non-probabilistic universe where everything in time and space is connected into one thing by quantum entanglement – making the brain and genes products of binary-digit activity or artificial intelligence (life is not merely dependent on biology’s “lock and key” mechanisms but also possesses AI). -/- The earliest documented representative of the genus Homo is Homo habilis, which evolved around 2.8 million years ago. Scientists used to believe there was a straight line from H. habilis to us, Homo sapiens. This article will use the “advanced” waves loved by Physics Nobel laureate Richard Feynman, view the history of science through the lens of Conic Sections applied to Relativity’s curved space-time, and incorporate the necessity of so-called imaginary time * – popularized by Prof. Stephen Hawking. While the evolutionary proposals are more in agreement with this early straight line than with modern theories, Albert Einstein’s General Relativity is used to transform the straight line into a curved line, ultimately concluding that Homo habilis (H. habilis) originated only (and unbelievably, as far as today’s science and technology is concerned) ~250,000 years ago. Other branches and dead ends of Homo – e.g. Neanderthals – are the result of mutations and adaptations, with the resultant modifications to anatomy and physiology. The surprisingly young age of H. habilis allows nearly 200,000 years for habilis, or one of its descendants, to reach Australia … if this country’s indigenous Aboriginal population did, as claimed, reach this “island continent” 60,000 years ago. -/- * The ultraviolet catastrophe, also called the Rayleigh–Jeans catastrophe, is a failure of classical physics to predict observed phenomena: it can be shown that a blackbody - a hypothetical perfect absorber and radiator of energy - would release an infinite amount of energy, contradicting the principles of conservation of energy and indicating that a new model for the behaviour of blackbodies was needed. At the start of the 20th century, physicist Max Planck derived the correct solution by making some strange (for the time) assumptions. In particular, Planck assumed that electromagnetic radiation can only be emitted or absorbed in discrete packets, called quanta. Albert Einstein postulated that Planck's quanta were real physical particles (what we now call photons), not just a mathematical fiction. From there, Einstein developed his explanation of the photoelectric effect (when quanta or photons of light shine on certain metals, electrons are released and can form an electric current). So it appears entirely possible that another supposed mathematical trickery (imaginary time and the y-axis of Wick rotation) will find practical application in the future. -/- The article includes mathematical references to cosmology (spoiler alert – you’ll read about things like Vector-Tensor-Scalar Geometry, topology, the “eternal present”, Einstein’s Unified Field, the inverse-square law, and there being no Big Bang and no multiverse - but there will also be no equations). -/- The other subheadings in this essay are – -/- NONLINEAR TIME AND ELECTRICAL ENGINEERING (about a 2009 electrical engineering experiment at America’s Yale University, and cosmic wormholes) -/- BITS AND TOPOLOGY (base-2 maths aka Binary digiTS, Mobius strips, and figure-8 Klein bottles) -/- WICK ROTATION, CAUSALITY, AND UNITING TIME (do past, present and future co-exist in an “eternal present”?) -/- DIGITAL BRAIN, DIGITAL UNIVERSE (if the brain and the universe are ultimately composed of binary digits, we'll someday be able to do the same things with the brain and universe that we now do with computers) -/- PROPOSAL: HUMAN AND ANIMAL INSTINCTS ARE THE RESULT OF THE UNIVERSE BEING UNIFIED BY BINARY DIGITS (AND TOPOLOGY) (If everything in the universe is ultimately composed of electronic BITS, then the universe must possess Artificial Intelligence - some prefer the term Cosmic Consciousness) -/- INFORMATION THEORY CONQUERS A RED GIANT (preserving Earth by keeping the Sun near today’s level of activity forever). 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In The Future of Human Nature, Jürgen Habermas raises the question of whether the embryonic genetic diagnosis and genetic modification threatens the foundations of the species ethics that underlies current understandings of morality. While morality, in the normative sense, is based on moral interactions enabling communicative action, justification, and reciprocal respect, the reification involved in the new technologies may preclude individuals to uphold a sense of the undisposability of human life and the inviolability of human beings that is necessary for (...) their own identity as well as for reciprocal relations. Engaging with liberal bioethics and Catholic approaches to bioethics, the article clarifies how Habermas’ position offers a radical critique of liberal autonomy while maintaining its postmetaphysical stance. The essay argues that Habermas’ approach may guide the question of rights of future generations regarding germline gene editing. But it calls for a different turn in the conversation between philosophy and theology, namely one that emphasizes the necessary attention to rights violations and injustices as a common, postmetaphysical starting point for critical theory and critical theology alike. In 2001, Jürgen Habermas published a short book on questions of biomedicine that took many by surprise.[1] To some of his students, the turn to a substantive position invoking the need to comment on a species ethics rather than outlining a public moral framework was seen as the departure from the “path of deontological virtue,”[2] and at the same time a departure from postmetaphysical reason. Habermas’ motivation to address the developments in biomedicine had certainly been sparked by the intense debate in Germany, the European Union, and internationally on human cloning, pre-implantation genetic diagnosis, embryonic stem cell research, and human enhancement. He turned to a strand of critical theory that had been pushed to the background by the younger Frankfurt School in favor of cultural theory and social critique, even though it had been an important element of its initial working programs. The relationship of instrumental reason and critical theory, examined, among others, by Max Horkheimer, Theodor W. Adorno, and Herbert Marcuse and taken up in Habermas’ own Knowledge and Interest and Theory of Communicative Action became ever-more actual with the development of the life sciences, human genome analysis, and genetic engineering of human offspring. Today, some of the fictional scenarios discussed at the end of the last century as “science fiction” have become reality: in 2018, the first “germline gene-edited” children were born in China.[3] Furthermore, the UK’s permission to create so-called “three-parent” children may create a legal and political pathway to hereditary germline interventions summarized under the name of “gene editing.”In this article, I want to explore Habermas’ “substantial” argument in the hope that philosophy and theology become allies in their struggle against an ever-more reifying lifeworld, which may create a “moral void” that would, at least from today’s perspective, be “unbearable”, and for upholding the conditions of human dignity, freedom, and justice. I will contextualize Habermas’ concerns in the broader discourse of bioethics, because only by doing this, his concerns are rescued from some misinterpretations.[1] Jürgen Habermas, The Future of Human Nature.[2] Ibid., 125, fn. 58. 8[3] Up to the present, no scientific publication of the exact procedure exists, but it is known that the scientist, Jiankui He, circumvented the existing national regulatory framework and may have misled the prospective parents about existing alternatives and the unprecedented nature of his conduct. Yuanwu Ma, Lianfeng Zhang, and Chuan Qin, "The First Genetically Gene‐Edited Babies: It's “Irresponsible and Too Early”," Animal Models and Experimental Medicine ; Matthias Braun, Meacham, Darian, "The Trust Game: Crispr for Human Germline Editing Unsettles Scientists and Society," EMBO reports 20, no. 2. (shrink)

Collected and edited by Noah Levin -/- Table of Contents: -/- UNIT ONE: INTRODUCTION TO CONTEMPORARY ETHICS: TECHNOLOGY, AFFIRMATIVE ACTION, AND IMMIGRATION 1 The “Trolley Problem” and Self-Driving Cars: Your Car’s Moral Settings (Noah Levin) 2 What is Ethics and What Makes Something a Problem for Morality? (David Svolba) 3 Letter from the Birmingham City Jail (Martin Luther King, Jr) 4 A Defense of Affirmative Action (Noah Levin) 5 The Moral Issues of Immigration (B.M. Wooldridge) 6 The Ethics of our (...) Digital Selves (Noah Levin) -/- UNIT TWO: TORTURE, DEATH, AND THE “GREATER GOOD” 7 The Ethics of Torture (Martine Berenpas) 8 What Moral Obligations do we have (or not have) to Impoverished Peoples? (B.M. Wooldridge) 9 Euthanasia, or Mercy Killing (Nathan Nobis) 10 An Argument Against Capital Punishment (Noah Levin) 11 Common Arguments about Abortion (Nathan Nobis & Kristina Grob) 12 Better (Philosophical) Arguments about Abortion (Nathan Nobis & Kristina Grob) -/- UNIT THREE: PERSONS, AUTONOMY, THE ENVIRONMENT, AND RIGHTS 13 Animal Rights (Eduardo Salazar) 14 John Rawls and the “Veil of Ignorance” (Ben Davies) 15 Environmental Ethics: Climate Change (Jonathan Spelman) 16 Rape, Date Rape, and the “Affirmative Consent” Law in California (Noah Levin) 17 The Ethics of Pornography: Deliberating on a Modern Harm (Eduardo Salazar) 18 The Social Contract (Thomas Hobbes) -/- UNIT FOUR: HAPPINESS 19 Is Pleasure all that Matters? Thoughts on the “Experience Machine” (Prabhpal Singh) 20 Utilitarianism (J.S. Mill) 21 Utilitarianism: Pros and Cons (B.M. Wooldridge) 22 Existentialism, Genetic Engineering, and the Meaning of Life: The Fifths (Noah Levin) 23 The Solitude of the Self (Elizabeth Cady Stanton) 24 Game Theory, the Nash Equilibrium, and the Prisoner’s Dilemma (Douglas E. Hill) -/- UNIT FIVE: RELIGION, LAW, AND ABSOLUTE MORALITY 25 The Myth of Gyges and The Crito (Plato) 26 God, Morality, and Religion (Kristin Seemuth Whaley) 27 The Categorical Imperative (Immanuel Kant) 28 The Virtues (Aristotle) 29 Beyond Good and Evil (Friedrich Nietzsche) 30 Other Moral Theories: Subjectivism, Relativism, Emotivism, Intuitionism, etc. (Jan F. Jacko). (shrink)

There is a global shortage of organs for transplantation and despite many governments making significant changes to their organ donation systems, there are not enough kidneys available to meet the demand. This has led scientists and clinicians to explore alternative means of meeting this organ shortfall. One of the alternatives to human organ transplantation is xenotransplantation, which is the transplantation of organs, tissues, or cells between different species. The resurgence of interest in xenotransplantation and recent scientific breakthroughs suggest that (...) class='Hi'>genetically-engineered pigs may soon present a realistic alternative as sources of kidneys for clinical transplantation. It is therefore important for nurses and allied health professionals to understand what is involved in xenotransplantation and its future implications for their clinical practices. First, we explore the insufficiency of different organ donation systems to meet the kidney shortage. Second, we provide a background and a summary of the progress made so far in xenotransplantation research. Third, we discuss some of the scientific, technological, ethical, and economic issues associated with xenotransplantation. Finally, we summarise the literature on the attitudes of healthcare professionals toward xenotransplantation. (shrink)

This collection of articles was written over the last 10 years and edited them to bring them up to date (2017). All the articles are about human behavior (as are all articles by anyone about anything), and so about the limitations of having a recent monkey ancestry (8 million years or much less depending on viewpoint) and manifest words and deeds within the framework of our innate psychology as presented in the table of intentionality. As famous evolutionist Richard Leakey says, (...) it is critical to keep in mind not that we evolved from apes, but that in every important way, we are apes. If everyone was given a real understanding of this (i.e., of human ecology and psychology to actually give them some control over themselves), maybe civilization would have a chance. As things are however the leaders of society have no more grasp of things than their constituents and so collapse into anarchy is inevitable. -/- It is critical to understand why we behave as we do and so the first section presents articles that try to describe (not explain as Wittgenstein insisted) behavior. Section one starts with a brief review of the logical structure of rationality which provides some heuristics for the description of language (mind) and gives some suggestions as to how this relates to the evolution of social behavior. This centers around the two writers I have found the most important in this regard, Ludwig Wittgenstein and John Searle, whose ideas I combine and extend within the dual system (two systems of thought) framework that has proven so useful in recent thinking and reasoning research. As I note, there is in my view essentially complete overlap between philosophy, in the strict sense of the enduring questions that concern the academic discipline, and the descriptive psychology of higher order thought (behavior). Once one has grasped Wittgenstein’s insight that there is only the issue of how the language game is to be played, one determines the Conditions of Satisfaction (what makes a statement true or satisfied etc.) and that is the end of the discussion. -/- Since philosophical problems are the result of our innate psychology, or as Wittgenstein put it, due to the lack of perspicuity of language, they run throughout human discourse, so there is endless need for philosophical analysis, not only in the ‘human sciences’ of philosophy, sociology, anthropology, political science, psychology, history, literature, religion, etc., but in the ‘hard sciences’ of physics, mathematics, and biology. It is universal to mix the language game questions with the real scientific ones as to what the empirical facts are. Scientism is ever present and the master has laid it before us long ago, i.e., Wittgenstein (hereafter W) beginning with the Blue and Brown Books in the early 1930’s. -/- "Philosophers constantly see the method of science before their eyes and are irresistibly tempted to ask and answer questions in the way science does. This tendency is the real source of metaphysics and leads the philosopher into complete darkness." (BBB p18) -/- The key to everything about us is biology, and it is obliviousness to it that leads millions of smart educated people like Obama, Chomsky, Clinton and the Pope to espouse suicidal utopian ideals that inexorably lead straight to Hell On Earth. As W noted, it is what is always before our eyes that is the hardest to see. We live in the world of conscious deliberative linguistic System 2, but it is unconscious, automatic reflexive System 1 that rules. This is the source of the universal blindness described by Searle’s The Phenomenological Illusion (TPI), Pinker’s Blank Slate and Tooby and Cosmides’ Standard Social Science Model. -/- The astute may wonder why we cannot see System 1 at work, but it is clearly counterproductive for an animal to be thinking about or second guessing every action, and in any case there is no time for the slow, massively integrated System 2 to be involved in the constant stream of split second ‘decisions’ we must make. As W noted, our ‘thoughts’ (T1 or the ‘thoughts’ of System 1) must lead directly to actions. -/- It is my contention that the table of intentionality (rationality, mind, thought, language, personality etc.) that features prominently here describes more or less accurately, or at least serves as an heuristic for, how we think and behave, and so it encompasses not merely philosophy and psychology, but everything else (history, literature, mathematics, politics etc.). Note especially that intentionality and rationality as I (along with Searle, Wittgenstein and others) view it, includes both conscious deliberative System 2 and unconscious automated System 1 actions or reflexes. -/- Thus all the articles, like all behavior, are intimately connected if one knows how to look at them. As I note, The Phenomenological Illusion (oblivion to our automated System 1) is universal and extends not merely throughout philosophy but throughout life. I am sure that Chomsky, Obama, Zuckerberg and the Pope would be incredulous if told that they suffer from the same problem as Hegel, Husserl and Heidegger, (or that that they differ only in degree from drug and sex addicts in being motivated by stimulation of their frontal cortices by the delivery of dopamine via the ventral tegmentum and the nucleus accumbens) but it’s clearly true. While the phenomenologists only wasted a lot of people’s time, they are wasting the earth and their descendant’s future. Section one continues with other views of behavior which my reviews attempt to correct and put in context with minimal theory. -/- The next section describes the digital delusions which confuse the language games of System 2 with the automatisms of System one, and so cannot distinguish biological machines (i.e., people) from other kinds of machines (i.e., computers). The ‘reductionist’ claim is that one can ‘explain’ behavior at a ‘lower’ level, but what actually happens is that one does not explain human behavior but a ‘stand in’ for it. Hence the title of Searle’s classic review of Dennett’s book (“Consciousness Explained”)— “Consciousness Explained Away”. In most contexts ‘reduction’ of higher level emergent behavior to brain functions, biochemistry, or physics is incoherent. Even for chemistry or physics the path is blocked by chaos and uncertainty. Anything can be ‘represented’ by equations, but when they ‘represent’ higher order behavior, it is not clear what the ‘results’ mean. Reductionist metaphysics is a joke but most scientists and philosophers lack the appropriate sense of humor. -/- Another hi-tech delusion is that the we will be saved from the pure evil (selfishness) of System 1 by computers/AI/robotics/ nanotech/genetic engineering created by System 2. The No Free Lunch principal tells us there will be serious and possibly fatal consequences. The adventurous may regard this principle as a higher order emergent expression of the Second Law of Thermodynamics. -/- The last section describes The One Big Happy Family Delusion , i.e., that we are selected for cooperation with everyone and that the euphonious ideals of Democracy, Diversity and Equality will lead us into utopia. Again the No Free Lunch Principle ought to warn us it cannot be true, and we see throughout history and all over the contemporary world, that without strict controls, selfishness and stupidity gain the upper hand and soon destroy any nation that embraces it. In addition, the monkey mind steeply discounts the future, and so we sell our descendant’s heritage for temporary comforts greatly exacerbating the problems. -/- I describe versions of this delusion (i.e., that we are basically ‘friendly’ if just given a chance) as it appears in some recent books on sociology/biology/economics. I end with an essay on the great tragedy playing out in America and the world, which can be seen as a direct result of our evolved psychology manifested as the inexorable machinations of System 1. Our evolved psychology, eminently adaptive and eugenic on the plains of Africa ca. 50,000 years ago, when many of our ancestors left Africa, to ca. 6 million years ago, when we split from chimpanzees (i.e., in the EEA or Environment of Evolutionary Adaptation), but now maladaptive and dysgenic and the source of our Suicidal Utopian Delusions. So, like all discussions of behavior, this book is about evolutionary strategies, selfish genes and inclusive fitness. (shrink)

This collection of articles was written over the last 10 years and edited to bring them up to date (2017). The copyright page has the date of the edition and new editions will be noted there as I edit old articles or add new ones. All the articles are about human behavior (as are all articles by anyone about anything), and so about the limitations of having a recent monkey ancestry (8 million years or much less depending on viewpoint) and (...) manifest words and deeds within the framework of our innate psychology as presented in the table of intentionality. As famous evolutionist Richard Leakey says, it is critical to keep in mind not that we evolved from apes, but that in every important way, we are apes. If everyone was given a real understanding of this (i.e., of human ecology and psychology to actually give them some control over themselves), maybe civilization would have a chance. As things are however the leaders of society have no more grasp of things than their constituents and so collapse into anarchy is inevitable. The first group of articles attempts to give some insight into how we behave that is reasonably free of the theoretical delusions that are universal. In the next group, I show how these insights apply by reviewing some books in philosophy and psychology. Next I review books on science and religion and finally provide reviews and articles showing how understanding of both science and philosophy gives insight into the tragic delusions destroying the world. People believe that society can be saved by science, religion and politics, so I provide some suggestions as to why this is unlikely via short articles and reviews of recent books by well-known writers. It is critical to understand why we behave as we do and so the first section presents articles that try to describe (not explain as Wittgenstein insisted) behavior. I start with a brief review of the logical structure of rationality, which provides some heuristics for the description of language (mind, rationality, personality) and gives some suggestions as to how this relates to the evolution of social behavior. This centers around the two writers I have found the most important in this regard, Ludwig Wittgenstein and John Searle, whose ideas I combine and extend within the dual system (two ii systems of thought) framework that has proven so useful in recent thinking and reasoning research. As I note, there is in my view essentially complete overlap between philosophy, in the strict sense of the enduring questions that concern the academic discipline, and the descriptive psychology of higher order thought (behavior). Once one has grasped Wittgenstein’s insight that there is only the issue of how the language game is to be played, one determines the Conditions of Satisfaction (what makes a statement true or satisfied etc.) and that is the end of the discussion. Since philosophical problems are the result of our innate psychology, or as Wittgenstein put it, due to the lack of perspicuity of language, they run throughout human discourse and behavior, so there is endless need for philosophical analysis, not only in the ‘human sciences’ of philosophy, sociology, anthropology, political science, psychology, history, literature, religion, etc., but in the ‘hard sciences’ of physics, mathematics, and biology. It is universal to mix the language game questions with the real scientific ones as to what the empirical facts are. Scientism is ever present and the master has laid it before us long ago, i.e., Wittgenstein (hereafter W) beginning with the Blue and Brown Books in the early 1930’s. "Philosophers constantly see the method of science before their eyes and are irresistibly tempted to ask and answer questions in the way science does. This tendency is the real source of metaphysics and leads the philosopher into complete darkness." (BBB p18) The key to everything about us is biology, and it is obliviousness to it that leads millions of smart educated people like Obama, Chomsky, Clinton and the Pope to espouse suicidal utopian ideals that inexorably lead straight to Hell on Earth. As W noted, it is what is always before our eyes that is the hardest to see. We live in the world of conscious deliberative linguistic System 2, but it is unconscious, automatic reflexive System 1 that rules. This is the source of the universal blindness described by Searle’s The Phenomenological Illusion (TPI), Pinker’s Blank Slate and Tooby and Cosmides’ Standard Social Science Model. The astute may wonder why we cannot see System 1 at work, but it is clearly counterproductive for an animal to be thinking about or second guessing every action, and in any case, there is no time for the slow, massively integrated System 2 to be involved in the constant stream of split second ‘decisions’ we must make. As W noted, our ‘thoughts’ (T1 or the ‘thoughts’ of System 1) must lead directly to actions. iii It is my contention that the table of intentionality (rationality, mind, thought, language, personality etc.) that features prominently here describes more or less accurately, or at least serves as an heuristic for, how we think and behave, and so it encompasses not merely philosophy and psychology, but everything else (history, literature, mathematics, politics etc.). Note especially that intentionality and rationality as I (along with Searle, Wittgenstein and others) view it, includes both conscious deliberative System 2 and unconscious automated System 1 actions or reflexes. Thus, all the articles, like all behavior, are intimately connected if one knows how to look at them. As I note, The Phenomenological Illusion (oblivion to our automated System 1) is universal and extends not merely throughout philosophy but throughout life. I am sure that Chomsky, Obama, Zuckerberg and the Pope would be incredulous if told that they suffer from the same problem as Hegel, Husserl and Heidegger, (or that that they differ only in degree from drug and sex addicts in being motivated by stimulation of their frontal cortices by the delivery of dopamine (and over 100 other chemicals) via the ventral tegmentum and the nucleus accumbens), but it’s clearly true. While the phenomenologists only wasted a lot of people’s time, they are wasting the earth and their descendant’s futures. Many of the articles describe the ‘digital delusions’, which confuse the language games of System 2 with the automatisms of System 1, and so cannot distinguish biological machines (i.e., people) from other kinds of machines (i.e., computers). The ‘reductionist’ claim is that one can ‘explain’ behavior at a ‘lower’ level, but what actually happens is that one does not explain human behavior but a ‘stand in’ for it. Hence the title of Searle’s classic review of Dennett’s book (“Consciousness Explained”)— “Consciousness Explained Away”. In most contexts ‘reduction’ of higher level emergent behavior to brain functions, biochemistry, or physics is incoherent. Also for ‘reduction’ of chemistry or physics, the path is blocked by chaos and uncertainty. Anything can be ‘represented’ by equations, but when they ‘represent’ higher order behavior, it is not clear (and cannot be made clear) what the ‘results’ mean. Reductionist metaphysics is a joke, but most scientists and philosophers lack the appropriate sense of humor. Other digital delusions are that we will be saved from the pure evil (selfishness) of System 1 by computers/AI/robotics/ nanotech/genetic engineering created by System 2. The No Free Lunch principal tells us there will be serious and possibly fatal consequences. The adventurous may regard this principle as a higher order emergent expression of the Second Law of Thermodynamics. Hi-tech enthusiasts hugely underestimate the problems iv resulting from unrestrained motherhood, and of course it is neither profitable nor politically correct (and now with third world supremacism dominant, not even possible) to be honest about it. The last section describes various versions of the ‘altruism delusion’ that we are selected for cooperation, and that the euphonious ideals of Democracy, Diversity and Equality will lead us into utopia, if we just manage things correctly (the possibility of politics). Again, the No Free Lunch Principle ought to warn us it cannot be true, and we see throughout history and all over the contemporary world, that without strict controls, selfishness and stupidity gain the upper hand and soon destroy any nation that embraces it. In addition, the monkey mind steeply discounts the future, and so we cooperate in selling our descendant’s heritage for temporary comforts, greatly exacerbating the problems. I describe versions of this delusion (i.e., that we are basically ‘friendly’ if just given a chance) as it appears in some recent books on sociology/biology/economics. I end with an essay on the great tragedy playing out in America and the world, which can be seen as a direct result of our evolved psychology manifested as the inexorable machinations of System 1. Our psychology, eminently adaptive and eugenic on the plains of Africa from ca. 6 million years ago, when we split from chimpanzees, to ca. 50,000 years ago, when many of our ancestors left Africa (i.e., in the EEA or Environment of Evolutionary Adaptation), is now maladaptive and dysgenic and the source of our Suicidal Utopian Delusions. So, like all discussions of behavior (philosophy, psychology, sociology, biology, anthropology, politics, law, literature, history, economics, soccer strategies, business meetings, etc.), this book is about evolutionary strategies, selfish genes and inclusive fitness (kin selection). Many accept the delusion that we are selected for cooperation with people generally (group selection or altruism) and not just our immediate relatives (kin selection or inclusive fitness), so I spend some time in the essays of the last section demolishing this fantasy. One thing rarely mentioned by the group selectionists is the fact that, even were ‘group selection’ possible, selfishness is at least as likely (probably far more likely in most contexts) to be group selected for as altruism. Just try to find examples of true altruism in nature –the fact that we can’t (which we know is not possible if we understand evolution) tells us that its apparent presence in humans is an artefact of modern life concealing the facts, and that it can no more be selected for than the tendency to suicide (which in fact it is). One does not really need science or mathematics to grasp this – it is crushingly obvious that an v organism cannot be selected for behavior that decreases the frequency of its own genes in the next generation. One might also benefit from considering a phenomenon never (in my experience) mentioned by group selectionists -- cancer. No group has as much in common as the (originally) genetically identical cells in our own bodies-a 100 trillion cell clone-- but we are all born with thousands and perhaps millions of cells that have already taken the first step on the path to cancer and generate millions to billions of cancer cells in our life. If we did not die of other things first, we (and perhaps all multicellular organisms) would all die of cancer. Only a massive and hugely complex mechanism built into our genome that represses or derepresses trillions of genes in trillions of cells, and kills and creates billions of cells a second, keeps the majority of us alive long enough to reproduce. One might take this to imply that a just, democratic and enduring society for any kind of entity on any planet in any universe is only a dream, and that no being or power could make it otherwise. It is not only ‘the laws’ of physics that are universal and inescapable, or perhaps we should say that inclusive fitness is a law of physics. The great mystic Osho said that the separation of God and Heaven from Earth and Humankind was the most evil idea that ever entered the Human mind. In the 20th century an even more evil notion arose—that humans are born with rights, rather than having to earn privileges. Thus, every day the population increases by 200,000, who must be provided with resources to grow and space to live, and who soon produce another 200,000 etc. And one almost never hears it noted that what they receive must be taken from those already alive. Their lives diminish those already here in both major obvious and countless subtle ways. Every new baby destroys the earth from the moment of conception. There cannot be human rights without human wrongs. It cannot be more obvious, but one will never see the streets full of protesters against motherhood. America and the world are in the process of collapse from excessive population growth, most of it for the last century and now all of it due to 3rd world people. Consumption of resources and the addition of 4 billion more ca. 2100 will collapse industrial civilization and bring about starvation, disease, violence and war on a staggering scale. The earth loses about 2% of it’s topsoil every year, so as it nears 2100, most of it’s food growing capacity will be gone. Billions will die and nuclear war is all but certain. In America, this is being hugely accelerated by massive immigration and immigrant reproduction, combined with abuses made possible by democracy. Depraved human nature inexorably turns the dream of democracy and diversity into a vi nightmare of crime and poverty. China will continue to overwhelm America and the world, as long as it maintains the dictatorship which limits selfishness. The root cause of collapse is the inability of our innate psychology to adapt to the modern world, which leads people to treat unrelated persons as though they had common interests. This, plus ignorance of basic biology and psychology, leads to the social engineering delusions of the partially educated who control democratic societies. Few understand that if you help one person you harm someone else—there is no free lunch and every single item anyone consumes destroys the earth beyond repair. Consequently, social policies everywhere are unsustainable and one by one all societies without stringent controls on selfishness will collapse into anarchy or dictatorship. Without dramatic and immediate changes, there is no hope for preventing the collapse of America, or any country that follows a democratic system. The popular notions supported by the Democratic Party and Third World Supremacists are that Democracy, Diversity, Equality and Social Justice will produce a Utopia in America and the world, but it is clear as crystal that they unavoidably foster selfishness and divisiveness and are producing collapse. Hence my concluding essay “Suicide by Democracy”. The most basic facts, almost never mentioned, are that there are not enough resources in America or the world to lift a significant percentage of the poor out of poverty and keep them there. Even the attempt to do this is already bankrupting America and destroying the world. The earth’s capacity to produce food decreases daily, as does our genetic quality. And now, as always, by far the greatest enemy of the poor is other poor and not the rich. -/- My writings are available as paperbacks and Kindles on Amazon. -/- Talking Monkeys: Philosophy, Psychology, Science, Religion and Politics on a Doomed Planet - Articles and Reviews 2006-2017 (2017) ASIN B071HVC7YP. -/- The Logical Structure of Philosophy, Psychology, Mind and Language in Ludwig Wittgenstein and John Searle--Articles and Reviews 2006-2016 (2017) ASIN B071P1RP1B. -/- Suicidal Utopian Delusions in the 21st century: Philosophy, Human Nature and the Collapse of Civilization - Articles and Reviews 2006-2017 (2017) 2nd printing with corrections (Feb 2018) ASIN B0711R5LGX -/- Suicide by Democracy: an Obituary for America and the World (2018) ASIN B07CQVWV9C -/- . (shrink)

Conventional methods of genetic engineering and more recent genome editing techniques focus on identifying genetic target sequences for manipulation. This is a result of historical concept of the gene which was also the main assumption of the ENCODE project designed to identify all functional elements in the human genome sequence. However, the theoretical core concept changed dramatically. The old concept of genetic sequences which can be assembled and manipulated like molecular bricks has problems in explaining the natural genome-editing competences of (...) viruses and RNA consortia that are able to insert or delete, combine and recombine genetic sequences more precisely than random-like into cellular host organisms according to adaptational needs or even generate sequences de novo. Increasing knowledge about natural genome editing questions the traditional narrative of mutations (error replications) as essential for generating genetic diversity and genetic content arrangements in biological systems. This may have far-reaching consequences for our understanding of artificial genome editing. (shrink)

Imagine a world where everyone is healthy, intelligent, long living and happy. Intuitively this seems wonderful albeit unrealistic. However, recent scienti c breakthroughs in genetic engineering, namely CRISPR/Cas bring the question into public discourse, how the genetic enhancement of humans should be evaluated morally. In 2001, when preimplantation genetic diagnosis (PGD) and in vitro fertilisation (IVF), enabled parents to select between multiple embryos, Julian Savulescu introduced the principle of procreative bene cence (PPB), stating that parents have the obligations to choose (...) the child that is expected to have the best life. In this paper I argue that accepting the PPB and the consequentialist principle (CP) that two acts with the same consequences are morally on par, commits one to accepting the parental obligation of genetically enhancing one's children. (shrink)

Though many ethicists have the intuition that we should leave nature alone, Kyle Johannsen argues that we have a duty to research safe ways of providing large-scale assistance to wild animals. Using concepts from moral and political philosophy to analyze the issue of wild animal suffering (WAS), Johannsen explores how a collective, institutional obligation to assist wild animals should be understood. He claims that with enough research, genetic editing may one day give us the power to safely intervene (...) without perpetually interfering with wild animals’ liberties.---------------Questions addressed include: In what way is nature valuable and is interference compatible with that value? Is interference a requirement of justice? What are the implications of WAS for animal rights advocacy? What types of intervention are promising?---------------Expertly moving the debate about human relations with wild animals beyond its traditional confines, Wild Animal Ethics is essential reading for students and scholars of political philosophy and political theory studying animal ethics, environmental ethics, and environmental philosophy. (shrink)

In this new post-genomic age of medicine and biomedical technology, there will be novel approaches to understanding disease, and to finding drugs and cures for diseases. Hundreds of new “disease genes” thought to be the causative agents of various genetic maladies will be identified and added to the list of hundreds of such genes already identified. Based on this knowledge, many new genetic tests will be developed and used in genetic screening programs. Genetic screening is the foundation upon which reproductive (...) technologies such as pre-natal diagnosis (PND) and preimplantation genetic diagnosis (PGD) are based. Genetic information arising from the human genome may also be used in attempts to redesign the human genetic inheritance by engineering the human germline (germline engineering). In each of these technologies—PND, PGD, and germline engineering—there are serious ethical and social concerns. Moreover, all three are eugenic in nature because they strive to control which genes are passed down to future generations. The goals of this article are threefold: 1) to introduce the science behind the three technologies; 2) to give a brief overview of eugenics in the past century and show how these genetic technologies are eugenic; and 3) to present a vision of social justice that rejects the genetic determinism upon which eugenics is based and embraces a holistic, ecological view of nature and humanity. (shrink)

One of the most difficult issues to sort out morally is our obligation to future generations. Most individuals feel that they do indeed have some kind of obligation, but face difficulty in explaining the exact nature of the obligation. For one, it seems impossible to know the wants and desires of future generations, and furthermore the existence of the persons we are obligated to is entirely dependent upon the choices that we in fact make. In essence, we could shape future (...) generations so that they desire exactly what we provide for them. It seems that no matter what principle we adopt that is based upon these potential individuals we are led to absurd conclusions. Gregory Kavka calls this moral grappling the Paradox of Future Individuals. I believe that the ethical concerns surrounding genetic engineering should be seen as a specific instantiation of this Paradox and that by examining both we may be able to come up with some sort of working solution. Derek Parfit pleads ignorance as to a solution to this Paradox after an extensive exegesis on the issue, but as we may not be that far from shopping a genetic supermarket to determine the characteristics of our children I don’t believe we can settle for that conclusion. We will begin by examining the Paradox and suggested solutions to the Paradox. Next I will address how the Paradox relates directly to genetic engineering and discuss how rights-based arguments aimed against genetic engineering fail because of the nature of identity. Then I will consider how David Heyd’s Genero-centric principle applies to genetic engineering specifically and how a modified version of that principle may guide us out of the Paradox of Future Individuals in general. This solution may not be acceptable to utilitarian sensibilities, but it is because the numbers don’t add up that we may need to appeal to a different principle entirely. (shrink)

Against those who identify genealogy with reductive genealogical debunking or deny it any evaluative and action-guiding significance, I argue for the following three claims: that although genealogies, true to their Enlightenment origins, tend to trace the higher to the lower, they need not reduce the higher to the lower, but can elucidate the relation between them and put us in a position to think more realistically about both relata; that if we think of genealogy’s normative significance in terms of a (...) triadic model that includes the genealogy’s addressee, we can see that in tracing the higher to the lower, a genealogy can facilitate an evaluation of the higher element, and where the lower element is some important practical need rather than some sinister motive, the genealogy can even be vindicatory; and finally, that vindicatory genealogies can offer positive guidance on how to engineer better concepts. (shrink)

The scientific study of living organisms is permeated by machine and design metaphors. Genes are thought of as the ‘‘blueprint’’ of an organism, organisms are ‘‘reverse engineered’’ to discover their functionality, and living cells are compared to biochemical factories, complete with assembly lines, transport systems, messenger circuits, etc. Although the notion of design is indispensable to think about adaptations, and engineering analogies have considerable heuristic value (e.g., optimality assumptions), we argue they are limited in several important respects. In particular, (...) the analogy with human-made machines falters when we move down to the level of molecular biology and genetics. Living organisms are far more messy and less transparent than human-made machines. Notoriously, evolution is an opportunistic tinkerer, blindly stumbling on ‘‘designs’’ that no sensible engineer would come up with. Despite impressive technological innovation, the prospect of artificially designing new life forms from scratch has proven more difficult than the superficial analogy with ‘‘programming’’ the right ‘‘software’’ would suggest. The idea of applying straightforward engineering approaches to living systems and their genomes— isolating functional components, designing new parts from scratch, recombining and assembling them into novel life forms—pushes the analogy with human artifacts beyond its limits. In the absence of a one-to-one correspondence between genotype and phenotype, there is no straightforward way to implement novel biological functions and design new life forms. Both the developmental complexity of gene expression and the multifarious interactions of genes and environments are serious obstacles for ‘‘engineering’’ a particular phenotype. The problem of reverse-engineering a desired phenotype to its genetic ‘‘instructions’’ is probably intractable for any but the most simple phenotypes. Recent developments in the field of bio-engineering and synthetic biology reflect these limitations. Instead of genetically engineering a desired trait from scratch, as the machine/engineering metaphor promises, researchers are making greater strides by co-opting natural selection to ‘‘search’’ for a suitable genotype, or by borrowing and recombining genetic material from extant life forms. (shrink)

GAMETOGÊNESE -/- Emanuel Isaque Cordeiro da Silva Instituto Agronômico de Pernambuco Departamento de Zootecnia – UFRPE Embrapa Semiárido -/- • _____OBJETIVO -/- Os estudantes bem informados, estão a buscando conhecimento a todo momento. O estudante de Veterinária e Zootecnia, sabe que a Reprodução é uma área de primordial importância para sua carreira. Logo, o conhecimento da mesma torna-se indispensável. No primeiro trabalho da série fisiologia reprodutiva dos animais domésticos, foi abordado de forma clara, didática e objetiva os mecanismos de diferenciação (...) sexual dos embriões em desenvolvimento, quais os genes envolvidos nesse processo e tudo mais. Nesse segundo trabalho, a abordagem será teórica, mas também clara, sobre a formação primordial dos gametas femininos e masculinos, através da ovogênese nas fêmeas e a espermatogênese nos machos. Esse trabalho visa levar a importância do processo de formação dos gametas e a produção hormonal das gônadas, bem como o entendimento sobre as interações com o eixo hipotálamo-hipofisário. -/- •____INTRODUÇÃO -/- A reprodução sexual é um processo mediante a qual dois organismos da mesma espécie unem seu material genético para dar lugar a um organismo fixo com combinação única de genes; para isso, cada organismo produz células que contém a metade do material genético característico da espécie. Essas células haploides (1n) são denominadas gametas; ao combinar-se um gameta masculino com um feminino produz-se uma célula diploide (2n) (zigoto ou ovo) a partir da qual se forma o embrião. A grande maioria das espécies com reprodução sexual são anisogâmicas, o que significa que produzem dois tipos de gametas diferentes: os gametas masculinos são microscópios, móveis e produzem-se em grande quantidade, enquanto que os femininos são grandes, imóveis e produzem-se em menor quantidade. O tipo de gameta que um indivíduo produz é o que define seu sexo; sobre os animais o macho é o indivíduo que produz grandes quantidades de espermatozoides e a fêmea produz uma menor quantidade de óvulos, enquanto que nas plantas as gônadas masculinas são as produtoras pólen e as femininas produzem oosferas. Os gametas são diferentes do resto das células do organismo, as quais se chamam células somáticas; essas últimas são diploides porque contém dois pares de cromossomos, um par herdado do pai do indivíduo e o outro da mãe. As células somáticas, ademais, se dividem por mitose, ao qual os cromossomos se duplicam antes de cada divisão celular e cada uma das células filhas recebe um complemento diploide idêntico dos cromossomos, logo todas as células somáticas de um indivíduo possuem o mesmo material genético, embora cada tipo celular expresse diferentes combinações de genes. Em contraponto, os gametas são células haploides porque possuem somente um par de cromossomos e a metade do material genético característico da espécie. Cada um dos cromossomos em um gameta é resultado da recombinação dos genes contidos nos cromossomos paterno e materno do indivíduo que originam o gameta, e cada um destes possuem uma combinação única de genes. Os gametas se formam a partir das células germinais, que são células que em sua origem são diploides e elas de “comprometem” a manter-se como uma linha celular especial que em determinado momento sofrerá o processo de meiose para dar origem aos gametas haploides, sejam óvulos ou espermatozoides segundo o sexo do animal. Como descrito no trabalho sobre a diferenciação sexual, as células germinativas primordiais originam-se no epiblasto do embrião, e migram desde o saco vitelino até colonizar as cristas gonodais, onde, por sua vez, proliferam-se e se organizam junto com as células somáticas da gônada primitiva para formar o testículo ou o ovário. As células germinais masculinas e femininas tem a mesma origem embrionária. As gônadas indiferenciadas em um embrião possuem três tipos celulares: as células que dão origem aos gametas (ovogonia ou espermatogonia), as precursoras de células que nutrem os gametas em desenvolvimento (células da granulosa no ovário; células de Sertoli no testículo) e as precursoras de células que secretam hormônios sexuais (células da teca no ovário; células de Leydig no testículo). As células germinais são as únicas estruturas do organismo que têm a capacidade de dividir-se por meiose sofrendo uma redução no número de seus cromossomos, sendo responsável pela transmissão da carga genética aos descendentes. Em contraste, as células somáticas somente se dividem por mitose. A formação dos gametas compreende fases sequenciais de mitose, meiose e pós-meiose. Esses processos são altamente organizados e necessitam de um preciso e bem coordenado programa de expressão genética. Uma das características importantes da gametogênese é a redução cromossômica, que através da meiose, reduz pela metade o número de cromossomos e produz células distintas entre si, devido a trocas de material genético entre os pares de cromossomos provenientes do pai e da mãe, o que ocorre no processo de “crossing over” durante a primeira fase da meiose. A gametogênese é o processo mediante o qual as células germinais de cada sexo se multiplicam, dividem e diferenciam até formar os gametas. No caso da formação dos gametas masculinos o processo recebe o nome específico de espermatogênese, e para os gametas femininos é denominado como ovogênese. Embora os dois processos alcancem o objetivo comum de produção das células haploides, por onde compartilham algumas características, existem diferenças marcadas entre eles devido a necessidade de produzir um número muito distinto de gametas, de tamanho diferente, e com características de motilidade também distintas. -/- •___ESPERMATOGÊNESE -/- A espermatogênese é o processo mediante o qual se produz os gametas masculinos denominados espermatozoides. Durante a vida fetal as células germinais e as células somáticas do testículo em formação organizam-se em túbulos seminíferos que se derivam dos cordões sexuais primários e conformam a maior parte da medula do testículo. Na etapa fetal cada tubo seminífero é delimitado por uma membrana basal, recoberta na parte interior pelas células precursoras das células de Sertoli (um tipo de células somáticas). No exterior do túbulo localizam-se as células precursoras das células de Leydig ou intersticiais (figura 1), que também são células somáticas. Entre a membrana basal e as células de Sertoli encontram-se algumas células germinais denominadas espermatogonias de reserva A0 (denominadas gonócitos) que serão o único tipo de células germinais presentes no testículo enquanto o animal não alcançar a puberdade. As células de Sertoli estabelecem na região basal uniões oclusoras entre si, formando parte da barreira hemato-testicular. As espermatogonias A0 localizam-se por dentro da membrana basal do túbulo seminífero, embora fora da barreira hemato-testicular. Figura 1: fase neonatal. Nota-se a grande infiltração de tecido intersticial em quase 50% da seção originando que os túbulos sejam pequenos e redondos em sua maioria. O citoplasma e núcleo das células pré-Leydig são notadas claramente por essa ser uma espécie suína onde o tecido intersticial está claramente diferenciado. Hematoxilina-eosina (X 220.5). Fonte: Embrapa. -/- O número de células de Sertoli no testículo depende da influência do hormônio folículo estimulante (FSH) presente durante a vida fetal e as primeiras etapas de vida pós-natal. A população de células de Sertoli ao chegar a puberdade se manterá fixa durante o resto da vida do animal; existe uma relação positiva entre o tamanho e a população de células de Sertoli e a capacidade de produção de espermatozoides do testículo. As células de Sertoli são as únicas células somáticas que estão no epitélio seminífero, e sua função é a nutrição, sustentação e controle endócrino das células germinais. As células de Sertoli participam ativamente no processo de liberação dos espermatozoides para a luz do túbulo. Nesse momento, as células de Sertoli realizam a fagocitose de parte do citoplasma do espermatozoide dos chamados corpos residuais. As células de Sertoli também fagocitam as células germinais que se degeneram no curso normal da espermatogênese. Essas células ainda sintetizam grande quantidade de proteínas, como por exemplo as proteínas ABP (androgen hinding protein), que transportam andrógenos para todo o aparelho reprodutivo, transferrinas, que transportam ferro para a respiração celular das células germinais e também às inibinas, que regulam a liberação de FSH pela hipófise, através de um sistema de retroalimentação (feedback) negativa (figura 2). Figura 2: epitélio seminífero, células de Sertoli (flecha) (400 X). Fonte: Embrapa. -/- Antes da puberdade dos túbulos seminíferos observam-se ao corte como estruturas de diâmetro pequeno, sem luz, e conformados unicamente pelas células de Sertoli e espermatogonias de reserva e rodeados por abundante tecido intersticial, ao que estão presentes as células precursoras das células de Leydig. Ainda antes da puberdade, a diferenciação celular manifesta-se primeiro pela presença de espermatócitos primários, os quais se degeneram em geral na fase de paquíteno, por falta de estimulação hormonal. A partir de que o animal chega a puberdade inicia-se o processo de espermatogênese, que se manterá durante toda a vida do animal, exceto em espécies de animais silvestres muito estacionais, ao qual pode se suspender durante a época não reprodutiva para voltar e ser retomada na época ou estação reprodutiva. Depois da puberdade, os túbulos seminíferos possuem um diâmetro muito maior; em seu interior observa-se um grande número de células germinais de todos os tipos, diferentes estádios de divisão, e em seu lúmen contém líquido e espermatozoides. Ainda sobre o alcancei da puberdade, as espermatogonias começam a dividir-se aceleradamente por mitose, enquanto que no espaço intersticial as células mesenquimais também começam a se diferenciar e a dar origem as células de Leydig (figura 3). A partir dessa etapa as células de Leydig (totalmente diferenciadas) são também evidentes no exterior do túbulo, junto com as células mioides ou peritubulares que o rodeiam o que ao contrair-se são responsáveis por controlar o avanço dos fluidos e as células presentes no lúmen do túbulo. As células mioides estão situadas ao redor do túbulo, e é creditado a elas a promoção da contração e da integridade estrutural do túbulo. Esse tipo celular apenas se diferencia na puberdade pela ação dos andrógenos (figura 4). As interações entre as células de Sertoli e as mioides parecem ter um papel importante na manutenção das funções do testículo. Durante o processo de espermatogênese, as espermatogonias de reserva dividem-se periodicamente e enquanto algumas células fixas permanecem como espermatogonias de reserva, outras proliferam e sofrem uma seção de divisões mitóticas durante as quais se vão diferenciando até formarem espermatócitos primários (espermatocitogênese ou fase de mitose), logo sofrem divisões especiais mediante as quais reduzem seu número de cromossomos (fase de meiose), e ao final trocam de forma para converter-se em espermatozoides (espermatocitogênese) (figura 5). Cada uma dessas etapas da espermato- gênese será descrito detalhadamente adiante, antes é necessário a explicação de algumas características das células de Sertoli e de Leydig que ajudarão a entender seu papel durante a espermatogênese. Figura 3: células de Leydig no espaço intersticial do testículo bovino adulto PAS (400 X). Fonte: Embrapa. -/- Figura 4: o estabelecimento da puberdade pela presença de espermatozoides no túbulo. Hematoxilina-eosina (400 X). Fonte: Embrapa. Figura 5: fases mitóticas das espermatogonias (A0 e B) para formação de um espermatócito primário e as duas fases de meiose que se sucedem antes da espermatogênese. Fonte: ZARCO, 2018. -/- Ao início da espermatocitogênese as uniões oclusoras entre as células de Sertoli se abrem por etapas (como as comportas de um submarino) para permitir a passagem das espermatogonias em direção ao centro do túbulo seminífero sem que se estabeleça uma continuidade entre o exterior e o interior da barreira hemato-testicular. Uma vez ultrapassada essa barreira, as sucessivas gerações de espermatogonias, espermatócitos, espermátides e espermatozoides irão se localizar em direção ao interior do túbulo seminífero, em estreita associação com as células de Sertoli. Em consequência, as células de Sertoli dividem o túbulo seminífero em dois compartimentos; o compartimento basal (debaixo das uniões oclusoras das células de Sertoli), ao qual residem as espermatogonias de reserva, e o compartimento adluminal (em direção ao centro do túbulo), cujos espaços entre as células de Sertoli desenvolvem o resto do processo de espermatogênese (meiose e espermatocitogênese). Esse feito é importante porque durante a vida fetal as únicas células germinais existentes eram as espermatogonias de reserva, pelo que os antígenos expressados por gerações mais avançadas (espermatogonias intermediárias, secundárias, espermátides e espermatozoides) não são reconhecidos como próprios do corpo pelo sistema imunológico. Logo, o anterior implica que deve existir uma barreira entre eles e o sangue para evitar um ataque imunológico. Em todas as etapas da espermatogênese, as células de Sertoli atuam como células de suporte para as células germinais, que sempre permanecem recoberta pela membrana das células de Sertoli. Também atuam como células nutricionais já que proporcionam o meio em que as células germinais se desenvolvem e maturam, assim como as substâncias que regulam e sincronizam as sucessivas divisões e transformações das células germinais. As células de Sertoli produzem hormônios, como estrógenos e inibina que atuam sobre a hipófise para regular a secreção das gonadotropinas que controlam a espermatogênese. As células de Leydig que residem no exterior do túbulo seminífero também são importantes para a espermatogênese: produzem a testosterona que estimula e mantém a espermatogênese, bem como serve como substrato sobre o qual atua como aromatizador das células de Sertoli para transformá-las em estrógenos. Como supracitado, para seu estudo podemos dividir a espermatogênese em três fase: espermatocitogênese, meiose e espermiogênese (figura 6). Agora, serão descritas cada uma dessas etapas. Em algumas espécies, incluindo no homem, os macrófagos representam o segundo tipo celular intersticial mais numeroso no testículo, depois das células de Leydig. Os macrófagos e vários subtipos de linfócitos são identificados nós testículos de ovinos e ratos. Eles estão intimamente associados com as células de Leydig e atuam juntamente na regulação da esteroidogênese. Figura 6: fluxograma da espermatogênese. -/- Espermatocitogênese -/- A espermatocitogênese, também chamada de etapa proliferativa ou de mitose, consiste numa série de divisões mitóticas sofridas pelas células descendentes de uma espermatogonia de reserva. Uma vez que a célula se divide, abandona o estado de reserva e começa um processo de diferenciação. As espermatogonias de reserva (denominadas espermatogonias A0 na rata ou As nos humanos) são células que existem desde a vida fetal e que permanecem mitoticamente inativas durante a infância. Uma vez que alcançam a puberdade começam a dividir-se em intervalos regulares, e as células filhas podem permanecer como espermatogonias de reserva ou abandonar a reserva e ingressar na dita espermatocitogênese. Uma vez abandonada a reserva, as células filhas que vão se formando em cada divisão permanecem unidas por pontes citoplasmáticas, constituindo um clone que se divide sincronicamente. As células que se formam depois de cada divisão continuam sendo espermatogonias, porém cada geração é ligeiramente diferente da anterior. Na rata, por exemplo, as espermatogonias tipo A0 ao dividir-se originam espermatogonias do tipo A1, que em sucessivas divisões formam espermatogonias dos tipos A2, A3 e A4, as quais, por sua vez, sofrem outra mitose para formar espermatogonias intermediárias e uma mais para formar espermatogonias do tipo B. Essas últimas se diferenciam (sem se dividir) em espermatócitos primários, processo em que termina a fase de espermatocitogênese, que literalmente significa processo de geração de espermatócitos. As espermatogonias tipo A0 são a fonte para a contínua produção de gametas. A metade delas se dividem e formam células iguais (as chamadas células tronco) e a outra metade forma as espermatogonias A1, que sofre novas divisões mitóticas e formam os tipos 2, 3 e 4. O tipo A4 sofre mitose para formar a intermediária (A In), que por mitose, forma a tipo B (figura 6). Esses tipos de espermatogonias podem ser identificadas em evoluções histológicas de acordo com sua organização topográfica na membrana basal dos túbulos seminíferos ou mediante seu conteúdo de heterocromatina. Outra maneira de diferenciação se baseia em marcadores moleculares específicos que distinguem as espermatogonias tronco (A0) das demais, com os fins de isolamento, desenvolvimento in vitro e transplante. As tipo B passam por mitose para formarem os espermatócitos primários; estes iniciam a primeira etapa da meiose formando os espermatócitos secundários; na segunda etapa da divisão meiótica, cada espermatócito secundário se divide e formam as chamadas espermátides. Quando o testículo alcança seu desenvolvimento total, a meiose completa-se e as espermátides originadas se convertem em espermatozoides. Um dos maiores sinais característicos desse fenômeno é o alargamento das espermátides e sua migração em direção ao lúmen do túbulo seminífero (figuras 4, 7 e 8). Figura 7: espermatogonias marcadas por imuno-histoquímica, anticorpo monoclonal TGFa (400 x). Figura 8: fases de divisões meióticas (M), espermatócitos em paquíteno (PA) e espermatócitos secundários (ES). -/- Figura 9: estádio posterior a liberação dos espermatozoides na luz do túbulo. Hematoxilina-eosina (400 x). Mediante as seis divisões mitóticas que ocorrem durante a espermatocitogênese se forma potencialmente um clone de 64 espermatócitos primários a partir de cada espermatogonia A que ingressa sobre o processo. Não obstante, algumas células sofrem apoptose em cada uma das etapas do processo, ao qual o número real formado é menor. Em outras espécies produzem-se um transcurso similar de divisões mitóticas sucessivas durante a espermatocitogênese, embora a nomenclatura utilizada possa ser distinta, por exemplo nos bovinos as duas últimas divisões mitóticas dão origem as espermatogonias de tipo B1 e B2. -/- Meiose -/- Uma vez que as espermatogonias B se diferenciam em espermatócitos primários, esses iniciam a etapa de meiose, com uma nova divisão; desta vez a divisão é do tipo meiótica. Ao completar-se a primeira divisão meiótica (meiose I) se obtém os espermató-citos secundários, que ao sofrer a segunda divisão meiótica (meiose II) dão origem as espermátides. Vale salientar que a meiose é o processo mediante o qual reduz-se a metade do número de cromossomos, pelo que as espermátides que se obtém são células haploides (1n). Os espermatócitos secundários que se formam depois da primeira divisão meiótica contém a metade do número normal de cromossomos, porém a mesma quantidade de DNA já que cada cromossomo é duplo. As espermátides formadas na conclusão da segunda divisão meiótica (figura 7), por sua vez, contém a metade dos cromossomos, e esse já não são duplos, já que se trata de células 1n. Também deve-se enfatizar que durante a meiose é relevante o entrecruzamento dos cromossomos homólogos, pelo que cada espermátide possui uma combinação única e diferente de genes paternos e maternos. Outro ponto que deve ser levado em consideração é que cada espermátide somente possui um cromossomo sexual; a metade das espermátides contém o cromossomo X herdado da mãe do macho que está levando a cabo a espermatogênese e a outra metade contém o cromossomo Y herdado de seu pai. Para cada espermatócito primário que entra no processo de meiose obtém-se cerca de quatro espermátides, pelo qual ao ser completada a meiose potencialmente se poderiam formar até 256 espermátides por cada espermatogonia que abandona a reserva e ingressa na espermatocitogênese. -/- Espermiogênese -/- Durante a espermiogênese, também chamada de fase de diferenciação, as esper-mátides sofrem, sem se dividir, uma metamorfose que as transforma em espermatozoides, os quais finalmente são liberados das células de Sertoli em direção ao lúmen do túbulo seminífero. A espermiogênese é um processo complicado e longo já que a espermátide deve sofrer complexas trocas nucleares, citoplasmáticas e morfológicas que resultam na forma-ção dos espermatozoides. Algumas dessas mudanças incluem a condensação do material nuclear para formação de um núcleo plano e denso, a eliminação do citoplasma para a constituição de uma célula pequena, a formação de uma estrutura especializada denomi-nada acrossomo ou tampa cefálica, e a formação do pescoço e da cauda (flagelo) do esper-matozoide, do que depende a sua motilidade. Durante a maior parte da espermiogênese, as espermátides se mantém com uma estreita associação com as células de Sertoli; logo, chega-se a observar, então, flagelos que se projetam em direção a luz do túbulo que pare-cem sair das células de Sertoli, sendo na realidade os flagelos dos espermatozoides que ainda não tinham sido liberados pelo lúmen. Ao liberar os espermatozoides em direção a luz do túbulo, as células de Sertoli realizam a fagocitose de parte do citoplasma dos espermatozoides (corpos residuais). Também fagocitam os restos de todas as células germinais que sofrem apoptose ou degeneram-se durante a espermatogênese. Credita-se que ao realizar essas funções as células de Sertoli podem fazer uma monitoração eficiente da espermatogênese, o que lhes permitiria emitir sinais para colaborar na regulação desse processo em nível gonodal e a nível sistêmico através da secreção de hormônios como a inibina e o estradiol. Além da inibina e activina, as células de Sertoli sintetizam outras proteínas, como a ABP (proteína ligadora de andrógenos) que serve como uma molécula de transporte de andrógenos dentro dos túbulos seminíferos, ductos deferentes e epidídimo, ou a transfer-rina, que transporta o ferro necessário para a respiração celular. -/- Resultados da espermatogênese -/- O resultado da espermatogênese não significa apenas uma simples multiplicação das células germinais (até 256 espermatozoides a partir de cada espermatogonia A1), senão que através dela são produzidos gametas haploides pequenos, móveis e com grande diversidade genética entre eles, ao mesmo tempo que se mantêm uma reversa de células mãe (espermatogonias A0) a partir das quais se poderiam originar novos ciclos de esper-matogênese durante o resto da vida do animal. -/- Controle hormonal da espermatogênese -/- Como mencionado, o FSH reproduz um importante papel para o estabelecimento das células de Sertoli durante a vida fetal e início da vida pós-natal. O começo da esper-matogênese também é estimulado pelo FSH, que atua sobre as células de Sertoli para estimular sua função e a ativação de sinais dessas células em direção as células germinais, incluindo-as a abandonar a reserva e ingressar na espermatogênese. O FSH, assim mesmo, estimula a mitose durante o resto da espermatogênese e aumenta a eficiência do processo, já que reduz a apoptose e a degeneração de espermatogonias intermediárias e do tipo B. O FSH também estimula as células de Sertoli para produzirem inibina e ABP. Uma vez iniciada a espermatogênese somente requerem níveis baixos de FSH para se mantê-la. As células de Sertoli também devem ser estimuladas pela testosterona para funcio-nar de maneira adequada; se requer também do LH hipofisário: hormônio que estimula as células de Leydig para produzir testosterona. Por sua vez, a secreção de LH e FSH é regulada pelo GnRH hipotalâmico: esse neurohormônio também faz parte do mecanismo de regulação da espermatogênese. A espermatogênese também é modulada em nível local mediante a produção de determinados fatores e interações entre as células. Dentro dos fatores locais podemos mencionar o fator de crescimento parecido com a insulina 1 (IGF-1), o fator de crescimen-to transformante beta (TGF- β), activina, ocitocina e diversas citocinas. Entre as intera-ções celulares existem tanto uniões de comunicação entre as células de Sertoli e as células germinais, como pontes citoplasmáticas entre todas as células germinais que formam o clone de células descendentes de uma espermatogonia A1. Uma vez que as células de Sertoli iniciam sua função na puberdade é possível manter experimentalmente a espermatogênese somente com testosterona, sem ser requeri-dos nenhum outro hormônio. A quantidade de espermatozoides produzidos, no entanto, é maior quando há presença do FSH. Abaixo do estímulo do FSH as células de Sertoli produzem estradiol e inibina, hormônios que geram uma retroalimentação sobre o eixo hipotálamo-hipofisário para a regulação da secreção de gonadotropinas. Em particular, a inibina reduz a secreção de FSH, pelo qual é factível que sirva como um sinal que evite uma excessiva estimulação as células de Sertoli. -/- Ciclo do epitélio seminífero -/- Em cada espécie as espermatogonias de reserva iniciam um novo processo de divi-sões celulares em intervalos fixos: a casa 14 dias no touro; 12 dias no garanhão e a cada 9 dias no cachaço (reprodutor suíno). A nova geração de células que começam a proliferar sobre a base do tubo deslocam-se em direção ao centro do túbulo a geração anterior, que por sua vez deslocam-se as gerações anteriores. Devido as mudanças que vão sofrendo cada geração celular se ajustam a tempos característicos de cada etapa, já que rodas as células em uma determinada seção do túbulo estão sincronizadas entre si pelas células de Sertoli; em cada espécie somente é possível encontrar um certo número de combinações celulares: 14 diferentes combinações no caso da rata, 8 no touro e 6 no ser humano. A sucessão de possíveis combinações até regressar a primeira combinação se conhece como o ciclo do epitélio seminífero. Na maioria das espécies os espermatozoides que são libera-dos em direção a luz do túbulo provém das células que entraram no processo de esperma-togênese quatro gerações antes que a geração que está ingressando nesse momento, pelo que a espermatogênese no touro dura ao redor de 60 dias e um pouco menos em outras espécies domésticas. Significa que os efeitos negativos das alterações na espermatogêne-se podem estar presentes até dois meses depois de que se produziram essas alterações. Como supracitado, geralmente se observa a mesma combinação celular em toda a área de uma determinada secção transversal do túbulo seminífero. No entanto, se fizermos uma série de secções, observa-se que ao longo do túbulo há uma sucessão ordenada de combinações (a primeira em uma determinada secção; a segunda combinação na seguinte secção, e assim sucessivamente em secções subsequentes até regressar a primeira combi-nação. Teremos, então, que ao início da divisão das espermatogonias A1 se produz de forma sincronizada em uma secção do túbulo, e vai-se transmitindo como uma onda peristáltica as secções adjacentes. Esse processo é denominado como onda do epitélio seminífero e graças à esse túbulo seminífero sempre tem secções em todas as etapas da espermatogênese, com o que se alcança uma produção constante de espermatozoides. -/- Alterações da espermatogênese -/- Nas espécies estacionais a espermatogênese, como já mencionado, pode reduzir-se ou inclusive suspender sua atividade fisiológica durante a época não reprodutiva dessas espécimes, porém esse processo fisiológico não pode ser considerado como uma altera-ção. No entanto, a espermatogênese só pode ser alterada pelas enfermidades ou por fatores externos. A principal causa de alterações na espermatogênese é o aumento da temperatura testicular. Por isso, os testículos são localizados na saco escrotal e são “caídos” para fora do corpo como pode-se observar nos bovinos, caprinos, ovinos, caninos e no próprio homem. A temperatura testicular deve estar cerca de 2 a 6 °C abaixo da temperatura corporal normal. As células germinais masculinas são sensíveis ao calor, pelo qual na maioria dos mamíferos os testículos se encontram fora da cavidade abdominal e existe um sofisticado sistema de termorregulação para mantê-los a uma temperatura menor que a corporal. Se a temperatura corporal for elevada ou se os testículos permanecerem na cavidade abdominal, ou ainda se os sistemas termorreguladores do testículo sejam afetados por fatores inflamatórios como edema ou falta de mobilidade testicular dentro do escroto, a temperatura do tecido testicular aumentará e a espermatogênese sofrerá alterações proporcionais ao excesso de temperatura e a duração da elevação. A espermatogênese também pode ser afetada pela exposição a hormônios ou a outras substâncias. É possível que a causa mais comum (sobretudo no homem) seja o uso de esteroides anabólicos, que elevam a concentração de andrógenos na circulação, provo-cando um feedback negativo sobre a secreção de gonadotropinas. Ao deixar de estimular-se o testículo pelas gonadotropinas, este deixará de produzir testosterona, e as concentra-ções de andrógeno exógeno nunca alcançará as altíssimas concentrações de testosterona que normalmente estão presentes a nível do tecido testicular por ser o local onde se produz o hormônio. Também se supõe que diversas substâncias com propriedades estrogênicas derivadas de processos industriais (indústria dos plásticos, hidrocarbonetos etc.) e presentes no ambiente (fatores xenobióticos) podem ser responsáveis pelas alterações na espermatogênese em diversas espécies, entre as quais se inclui o ser humano. -/- • OVOGÊNESE E FOLICULOGÊNESE -/- A ovogênese é o processo seguido pelas células germinais da fêmea para a forma-ção dos óvulos, que são células haploides. Durante a vida fetal as células germinais proliferam-se no ovário por mitose, formando um grande número de ovogonias, algumas das quais se diferenciam em ovócitos primários que iniciam sua primeira divisão meiótica para deter-se na prófase da divisão. Somente alguns desses ovócitos primários retornarão e concluirão a primeira divisão meiótica em algum momento da vida adulta do animal, dando origem a um ovócito secundário e a um corpo polar. O ovócito secundário inicia a sua segunda divisão meiótica, a qual volta a ficar suspensa até receber um estímulo apropriado, já que somente os ovócitos secundários que são ovulados e penetrados por um espermatozoide retornam e concluem a segunda divisão meiótica, dando origem a um óvulo (figura 10). O processo de ovogênese é realizado dentro dos folículos ovarianos, que também tem que sofrer um longo transcurso de desenvolvimento e diferenciação denominado foliculogênese pelo que a ovogênese como tal realiza-se dentro do marco desse último processo. Por essa razão, na seguinte seção descreverei tanto a ovogênese como a folicu-logênese, e a relação que existe entre ambos. Figura 10: representação da ovogênese. Na etapa de proliferação, as células germinais se diferen-ciam por mitose. A meiose I se caracteriza por uma prófase prolongada, ocorrendo a duplicação do DNA. Nas duas divisões, que ocorrem antes da ovulação e depois da fertilização, a quantidade de DNA é reduzida a 1n, com o fim de que a fusão dos pronúcles (singamia) pós-fertilização, seja gerado um zigoto com um número de cromossomos de 2n (diploide). -/- Geração de ovócitos primários e folículos primordiais Tanto a ovogênese como a foliculogênese iniciam-se durante a vida fetal, quando as células germinais primordiais provenientes do saco vitelino colonizam a gônada primitiva e, junto com as células somáticas z organizam-se para a formação dos cordões sexuais secundários, que se desenvolvem principalmente no córtex do ovário. Nesse período, as células germinais que colonizaram o ovário sofrem até 30 divisões mitóticas, proliferando-se até formar milhares ou milhões de ovogonias, que inicialmente formam “ninhos” constituídos cada um deles por um clone de várias ovogonias que descendem da mesma célula precursora e que se mantêm unidas por pontes citoplasmáticas, sincronizan-do suas divisões mitóticas. Nessa etapa alcança-se a máxima população de células germinais no ovário, que antes de nascer se reduzirá drasticamente por apoptose. No ovário do feto humano chegam a haver até sete milhões de células germinais que ao nascimento se reduzem a dois milhões. Os ovários fetais do bovino, de maneira análoga, chegam a ter até 2.100.000 células germinais, que ao nascimento reduzem para 130.000 aproximadamente. A redução no número de ovogonias produz-se ao mesmo tempo que essas células, que vêm dividindo-se por mitose e estão agrupadas em ninhos, iniciam sua primeira divisão meiótica para se transformarem em ovócitos primários: células germinais que se encontram em uma etapa de suspensão (diplóteno) da prófase da primeira divisão meiótica. Nesse período produz-se uma grande proporção de células germinais; as células somáticas dos cordões sexuais, por sua vez, emitem projeções citoplasmáticas que separam a isolam os ovócitos primários sobreviventes, ficando cada um deles rodeados por uma capa de células aplanadas da (pré) granulosa. Ao mesmo tempo em que se forma uma membrana basal entre as células da granulosa e o tecido intersticial do ovário. Ao ovócito primário rodeado de uma capa de células da (pré) granulosa aplanadas e delimita-das por uma membrana basal denomina-se de folículo primordial (figura 11). Nas vacas os folículos primordiais bem formados já estão presentes nos ovários a partir do dia 90 da gestação. A maioria dos folículos primordiais com os que nasce uma fêmea se manterão inativos durante um longo tempo; muitos deles durante toda a vida do animal. Nos folículos primordiais inativos tanto os ovócitos primários como as células da granulosa conservam sua forma original e mantém um metabolismo reduzido estritamente ao mínimo necessário para manter-se viáveis. Por essa razão, ao realizar um corte histológico de qualquer ovário as estruturas mais numerosas que se observam serão os folículos primordiais. No entanto, cada dia da vida de um animal, inclusive desde a vida fetal, um certo número de folículos primordiais reiniciam seu desenvolvimento, e a partir desse momento um folículo exclusivamente pode ter dois destinos: o primeiro, prosseguir seu desenvolvi-mento até chegar a ovular, e o segundo (que é muito mais frequente) encontrar em algum momento condições inadequadas que fazem fronteira com ele para parar seu desenvolvi-mento, levando-o a sofrer atresia e degenerar até desaparecer do ovário. Figura 11: sequência da foliculogênese apresentando as diferentes estruturas que podemos encontrar em cada fase. Fonte: ZARCO, 2018. Culminação da ovogênese A ovogênese somente se completará quando um ovócito primário reinicia a meio-se; completa sua primeira divisão meiótica para formar um ovócito secundário e um primeiro corpo polar e, quando, finalmente sofrer uma segunda divisão meiótica para formar um óvulo e um segundo corpo polar. Os óvulos são as células 1n que constituem os gametas femininos, pouco numerosos, grandes e imóveis. A grande maioria dos ovóci-tos primários, como veremos mais adiante, nunca retomam a meiose e, em consequência, não chegam a formar ovócitos secundários, e muitos dos ovócitos secundários tampouco sofrem uma segunda divisão meiótica, pelo que não chegam a formar os óvulos. Ao longo da vida de uma fêmea, na maioria das espécies, menos de 0,1% dos ovócitos primários (um a cada mil) chega a terminar a ovogênese, dando origem a um óvulo. O supracitado deve-se a que a ovogênese somente pode retomar-se e ser completa-da em ovócitos primários que se encontram dentro dos folículos primordiais que (uma vez ativados) vão alcançando diversas etapas de seu desenvolvimento em momentos precisos aos que encontram as condições ideais de oxigenação, nutrição, vascularização e exposição a fatores parácrinos e a exposição a concentrações de hormônios que se requerem para que o folículo continue em cada etapa de seu desenvolvimento com o processo de foliculogênese até chegar a ovular. Qualquer folículo que não esteja nessas condições ao longo do desenvolvimento sofrerá degeneração e atresia, pelo que o ovócito primário em seu interior nunca chegará ao ponto em que pode retomar a primeira divisão meiótica. No que resta da presente seção revisaremos o processo de foliculogênese em cujo marco se desenvolve a ovogênese; havemos que tomar de conta que essa última se limita ao que ocorre nas células germinais (ovogonia, ovócito primário, secundário e óvulo), pelo qual depende intimamente do desenvolvimento do folículo de que essas células formam parte. Em um princípio a ativação do folículo primordial e o desenvolvimento folicular são independentes das gonadotropinas: não se conhecem os mecanismos precisos median-te os quais um folículo primordial se ativa e reinicia seu desenvolvimento, nem como se decide quais folículos, dentre as dezenas de milhares de ou centenas de milhares presentes em um ovário se reativarão em um dia em particular. A reativação trata-se de uma liberação de influência de fatores inibidores, já que os folículos primordiais se reativam espontaneamente quando cultivados in vitro, isolados do resto do tecido ovariano. Uma vez que um folículo primordial se ativa, inicia-se um longo processo de desenvolvimento que somente depois de vários meses (ao redor de cinco meses no caso dos bovinos) o levará a um estádio em que seu desenvolvimento posterior requer a presença das gonado-tropinas; daí que se diz que as primeiras etapas do desenvolvimento são independentes das gonadotropinas. Durante a fase independente de gonadotropinas, um folículo primordial que tenha sido ativado e tenha começado a crescer; passará primeiro para a etapa de folículo primá-rio, caracterizada por conter um ovócito primário que está rodeado, por sua vez, por uma capa de células da granulosa, que não são planas, e sim cúbicas. Depois, se o folículo continuar crescendo se transformará em um folículo secundário, ao qual as células da granulosa começam a proliferar (aumentando em número) e se organizam em duas ou mais capas que rodeiam o ovócito primário. Entre o ovócito e as células da granulosa que o rodeiam se forma nesta uma zona pelúcida; ainda assim o ovócito mantém contato direto com essas células, mediante o estabelecimento de pontes citoplasmáticas que atravessam a zona pelúcida. Através dessas pontes citoplasmáticas as células da granulosa podem passar nutrientes e informação ao ovócito primário. O volume e o diâmetro do ovócito primário aumentam ao mesmo tempo que as células da granulosa proliferam-se, para incrementar as capas ao redor do ovócito. De maneira gradual o citoplasma do ovócito primário aumenta até 50 vezes seu volume e a proliferação das células continua. Esses folículos que possuem cada vez mais células e portanto mais capas de células da granulosa se denominam folículos secundários. Para evitar confusões, há a necessidade de nomen-clatura ao qual o folículo vá mudando de nome de primordial a primário e logo, de secun-dário, a terciário, por sua vez, o ovócito que encontra-se em seu interior, a todo momento, segue sendo um ovócito primário. Durante a etapa dependente de gonadotropinas, os folículos secundários começam a formar um espaço cheio de líquido, o antro folicular, desse modo se convertem em folí-culos terciários. Com a utilização de outra nomenclatura, a formação do antro marca a transição entre folículos pré-antrais (sem antro) e folículos antrais (com antro). Em algum momento dessa transição entre folículo secundário e terciário, também aparece a depen-dência de folículos em direção as gonadotropinas, pelo qual somente podem seguir crescendo na presença do hormônio luteinizante (LH) e do hormônio folículo estimulante (FSH). Nos bovinos e em outras espécies (para seu estudo), os folículos antrais são dividi-dos em pequenos, médios e grandes. Embora todos eles possuam um antro folicular, dependendo do seu grau de desenvolvimento requerem diferentes concentrações de gona-dotropinas para continuar o crescimento. Os folículos antrais mais pequenos somente re-querem concentrações baixas de LH e FSH, pelo qual podem continuar crescendo em qualquer momento do ciclo estral inclusive em animais que não estão ciclando (fêmeas em anestro pré-puberal, gestacional, lactacional, estacional). Nas etapas posteriores os folículos antrais requerem primeiro concentrações elevadas de FSH, e nas etapas finais somente podem continuar crescendo na presença de pulsos frequentes de LH, pelo qual somente os folículos que encontram-se sob concentrações apropriadas desses hormônios podem seguir crescendo. Por essa razão, nos animais que se encontram em anestro de qualquer tipo somente é possível encontrar folículos antrais pequenos ou médios, segundo a espécie, e nos animais que se encontram ciclando (estro) o maior tamanho folicular encontrado em um determinado dia do ciclo dependerá das concentrações de FSH e LH presentes nesse momento e nos dias anteriores. Um folículo que chega ao estado máximo de desenvolvimento, conhecido como folículo pré-ovulatório, ao final, somente chegará a ovular se for exposto a um pico pré-ovulatório de LH. Como supracitado, cada dia na vida de uma fêmea inicia seu desenvolvimento um certo número de folículos; a grande maioria sofrem atresia, mas depois da puberdade em cada dia do ciclo estral um ou vários folículos vão encontrando ao longo do seu desenvol-vimento concentrações hormonais que lhes permite chegar na etapa de folículo pré-ovula-tório. Somente nestes folículos, e como consequência de um pico pré-ovulatório de LH, se reinicia e completa-se a primeira divisão meiótica do ovócito primário, produzindo duas células distintas. Uma delas é o ovócito secundário, que retém praticamente todo o citoplasma. Contém, assim mesmo, em seu núcleo um par de cromossomos duplos, a outra é o primeiro corpo polar, que é exclusivamente um núcleo com uma quantidade mínima de citoplasma. Na maioria das espécies ovula-se um ovócito secundário que se encontra, então, suspendido na segunda divisão meiótica. Esta segunda divisão meiótica somente reinicia-rá e completarar-se uma vez que o espermatozoide começa a penetrar sob o ovócito secundário. Ao concluir-se a divisão se forma o segundo corpo polar e completa-se a ovogênese com o qual se obtém o óvulo, célula 1n que constitui o gameta feminino. No entanto, o óvulo existe pouco tempo como tal, já que em poucos minutos/horas (depen-dendo da espécie) se produzirá a fusão do núcleo do mesmo (pró-núcleo feminino) com o do espermatozoide (pró-núcleo masculino), com o qual se completa a fertilização e se forma um novo indivíduo (o ovo ou zigoto). -/- Ondas foliculares -/- Como mencionado supra, todos os dias um determinado número de folículos pri-mordiais se ativam e começam a crescer, os quais crescem em um ritmo característico em cada espécie. Isso provoca que em qualquer momento existam nos ovários folículos pri-mordiais (que começam a crescer em alguns dias ou semanas), assim como folículos secundários em diversas etapas do desenvolvimento, os quais iniciaram seu desenvolvi-mento em semanas ou inclusive meses (segundo o grau de desenvolvimento atual). Também em qualquer momento poderá haver folículos antrais nas etapas iniciais de seu desenvolvimento (com antros que já se podem detectar em cortes histológicos mas não são visíveis macroscopicamente). Todos esses folículos chegaram até seu estado de de-senvolvimento atual (primário, secundário ou antral pequeno), independente da etapa do ciclo estral em que sejam observados ou encontrados. Nos bovinos, os folículos que chegam ao início da etapa antral iniciaram seu desenvolvimento cinco meses antes, e todavia requerem ao redor de 42 dias para chegar ao estado pré-ovulatório. Para continuar seu desenvolvimento, os folículos antrais pequenos devem encon-trar concentrações altas de FSH, que os estimulam para prosseguir o crescimento. Cada vez que se produz uma elevação nas concentrações de FSH, esse hormônio estimula o desenvolvimento de um grupo de folículos antrais pequenos, que começaram a crescer muito tempo antes e que o dia da elevação de FSH tenha alcançado o grau de desenvolvi-mento preciso para responder com eficiência a este hormônio, o qual atuará através de seus receptores nas células da granulosa para estimular a produção de estradiol, a secreção de inibina, a produção de líquido folicular e a proliferação das células da granulosa. Um grupo de folículos antrais pequenos é assim recrutado pelo FSH para acelerar seu cresci-mento e aumentar sua produção de estradiol e inibina (figura 12). Mediante um seguimento ultrassonográfico dos ovários é possível identificar pou-cos dias depois um certo número de folículos, que por haver sido recrutados começam um período de crescimento acelerado. Durante alguns dias vários folículos crescem juntos, porém depois um deles é selecionado para continuar crescendo, enquanto que o restante do grupo deixam de fazê-lo e terminam sofrendo atresia. Através da ultrassom é possível identificar o folículo selecionado, agora chamado folículo domi-nante, já que sua trajetória de crescimento sofre um desvio com respeito a seguida pelo restante do grupo. Os folículos que não foram selecionados deixam de crescer e sofrem atresia já que deixam de possuir o suporte gonadotrópico de FSH, uma vez que as concentrações desse hormônio são suprimidos pela inibina e o estradiol produzidos pelo conjunto de folículos que conformam a onda folicular (figura 12), porém o folículo mais desenvolvido do grupo se converterá em dominante. A inibina atua diretamente a nível hipofisário para reduzir a secreção de FSH. Figura 12: onda folicular e relação dos níveis de FSH, estradiol e LH. Fonte: ZARCO, 2018. -/- Figura 13: Recrutamento, seleção e dominação folicular na espécie ovina e influência do FSH e LH nas fases. Fonte: SILVA, E. I. C. da, 2019. -/- A razão pela qual o folículo dominante é capaz de continuar seu desenvolvimento apesar da baixa nas concentrações de FSH é que o folículo é o único que alcançou o grau de progresso necessário para que apareçam os receptores para LH em suas células da granulosa. Esse processo permite ao folículo dominante ser estimulado pela LH, e que requeira baixas concentrações de FSH para manter seu desenvolvimento. A secreção de LH em forma de pulsos de baixa frequência (um pulso a cada quatro a seis horas), característica da fase lútea do ciclo estral; é suficiente para permitir que um folículo dominante continue crescendo por mais dias depois da sua seleção e que mais tarde mantenha-se viável durante alguns dias embora não aumentem de tamanho. Contu-do, se durante o período viável desse folículo não seja finalizada a fase lútea e não diminuam as concentrações de progesterona, o folículo terminará sofrendo atresia devido a exigência de um padrão de secreção acelerada de LH (aproximadamente um pulso por hora) durante o desenvolvimento pré-ovulatório, que somente pode ser produzido com a ausência da progesterona. Uma vez que um folículo dominante sofre atresia deixa de produzir inibina, pelo qual as concentrações de FSH podem elevar-se novamente para iniciar o recrutamento de outro grupo de folículos a partir da qual se origina uma nova onda folicular. Durante o ciclo estral de uma vaca podem gerar-se dois ou três ondas foliculares; somente em raros casos quatro. A etapa de dominância folicular da primeira onda na grande maioria dos casos não coincide com a regressão do corpo lúteo, pelo qual o primei-ro folículo dominante quase invariavelmente termina em atresia. Em algumas vacas o fo-lículo dominante da segunda onda ainda está viável quando se produz a regressão do corpo lúteo e acelera-se a secreção de LH, pelo qual esse segundo folículo dominante se converte em folículo pré-ovulatório e, ao final ovula. Em outros animais o segundo folícu-lo dominante também perde a sua viabilidade antes da regressão do corpo lúteo, por onde nesses animais se inicia uma terceira onda folicular, da qual surge o folículo que finalmen-te ovulará depois de produzir-se a regressão do corpo lúteo. Sem importar a onda em que se origine, uma vez que um folículo dominante é ex-posto a alta frequência de secreção de LH que se produz depois da regressão do corpo lúteo, aumenta ainda mais sua secreção de estradiol até que as altas concentrações desse hormônio comecem a exercer um feedback positivo para a secreção do LH. Isso provoca-rá a aceleração da frequência de secreção do LH até que os pulsos são tão frequentes que começam a ficar por cima e produzir-se o pico pré-ovulatório de LH, que é responsável pela realização da ovulação e a maturação final do ovócito. -/- •___DIFERENÇAS ENTRE ESPERMATOGÊNESE E OVOGÊNESE -/- Enquanto que na fêmea a ovogênese inicia-se durante a vida fetal, no macho a es-permatogênese começa na puberdade. Na fêmea, a partir de um ovócito primário se origi-na um óvulo; no macho, de um espermatócito primário se produzem, teoricamente, quatro espermatozoides. Outra característica interessante é que enquanto a fêmea já conta desde o nasci-mento com todos os ovócitos que necessitará na vida adulta, o macho necessitará chegar a puberdade para iniciar o desenvolvimento das células sexuais, já que ao nascer somente possui gonócitos precursores das células germinais, células de Sertoli e intersticiais. Na vida adulta de uma fêmea, o número de células germinais desaparece paulati-namente. Uma vez iniciada a espermatogênese no macho, a cada ciclo do epitélio seminí-fero as células germinais são renovadas mantendo a provisão para toda a vida reprodutiva. Na fêmea, a meiose sofre duas interrupções em seu transcurso, e no macho é ininterrupta. Figura 14: representação em diagramação comparativa do desenvolvimento da gametogênese. -/- Principais pontos abordados sobre as diferenças entre a gametogênese masculina e feminina: ❙ Na ovogênese a meiose contêm-se em duas ocasiões esperando acontecimentos externos para prosseguir. Já na espermatogênese não existe a suspensão da meiose. ❙ A espermatogênese é um processo contínuo, enquanto que a ovogênese pode completar exclusivamente um óvulo em cada ciclo estral; já que só pode ser completada por mais de um nas espécies que ovulam vários ovócitos no caso das porcas, cadelas, gatas etc. ❙ Na espermatogênese existem células de reserva que permitem a continuação du-rante toda a vida, enquanto que na ovogênese o número de ovócitos primários é limitado. A fêmea somente conta com os que nasceu, e eles não se dividem. ❙ Na espermatogênese obtém-se até 256 espermatozoides para cada espermatogo-nia que inicia o processo, enquanto que na ovogênese somente se obtém um óvulo a partir de cada ovócito primário. ❙ Durante a espermatogênese se produz uma metamorfose que transforma as es-permátides em espermatozoides. Na ovogênese não ocorre um processo análogo. ❙ Na espermatogênese, durante a meiose produzem-se quatro espermátides a partir de cada espermatócito primário. 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Social change is slow and difficult. Social change for animals is formidably slow and difficult. Advocates and scholars alike have long tried to change attitudes and convince the public that eating animals is wrong. The topic of norms and social change for animals has been neglected, which explains in part the relative failure of the animal protection movement to secure robust support reflected in social and legal norms. Moreover, animal ethics has suffered from a disproportionate focus on (...) individual attitudes and behavior at the expense of collective behavior, social change, and empirical psychology. If what we want to change is behavior on a large scale, norms are important tools. This article reviews an account of social norms that provides insights into the possibility and limitations of social change for animals, approaching animal protection as a problem of reverse social engineering. It highlights avenues for future work from this neglected perspective. (shrink)

This paper provides a historical analysis of a shift in the way animal models of mental disorders were conceptualized: the shift from the mid-twentieth-century view, adopted by some, that animal models model syndromes classified in manuals such as the Diagnostic and Statistical Manual of Mental Disorders (DSM), to the later widespread view that animal models model component parts of psychiatric syndromes. I argue that in the middle of the twentieth century the attempt to maximize the face validity of animal models (...) sometimes led to the pursuit of the ideal of an animal model that represented a behaviorally defined psychiatric syndrome as described in manuals such as the DSM. I show how developments within psychiatric genetics and related criticism of the DSM in the 1990s and 2000s led to the rejection of this ideal and how researchers in the first decade of the twenty-first century came to believe that animal models of mental disorders should model component parts of mental disorders, adopting a so-called endophenotype approach. (shrink)

Chimpanzee language studies have generated much heated controversy, as Roger Fouts can attest from firsthand experience. Perhaps this is because language is usually considered to be what truly distinguishes humans from apes. If chimps can indeed be taught the rudiments of language, then the difference between them and us is not as great as we might have thought. It is a matter of degree rather than kind, a continuity, and our species is not so special after all. The advantage of (...) this continuity thesis, as Fouts has emphasized, is that it conforms to the general tenets of evolutionary theory, and fits well with the evidence from paleontology and genetics that suggests that apes and humans are close cousins. It also .. (shrink)

Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 micrometres to 33.6 metres. In this paper an Artificial Neural Network (ANN) model, was developed and tested to predict animal species. There are a number of features that influence the classification of animal species. Such as the existence of hair/ feather, if the animal gives birth (...) or spawns, it is airborne, aquatic, predator, toothed, backboned, venomous, has –fins, has-tail, cat-sized, and domestic. A model based on the Multilayer Perceptron Topology was proposed and trained, using data set what was collected from UCI Machine Learning Repository. Evaluation of the proposed model shows that the ANN model is able to correctly predict the animal category with 100% accuracy. (shrink)

A current advance within the agricultural industry is the use of genetic engineering to produce novel crops for food production. This technology raises questions about how societies should position themselves with respect to genetically modified (GM) crop development and implementation; namely, how should the potentials and risks of this technology be evaluated? We argue that current methods to evaluate the risks and benefits of GM crops are inadequate and not conducive to the strategic development of this technology, where a (...) way to ameliorate technology assessments for GM crops is to include farmers in the research process of evaluating these crops prior to their commercialization. However, particularities concerning the ethical status of such research require special consideration and vigilance. For example, in such technology assessment initiatives, farmers would occupy both the roles of research participant and research investigator. Other particularities surface due to factors related to the nature of GM crops. These particularities are examined with reference to concepts drawn from the field of research ethics, namely informed consent, compensatory decisions, and issues of participant inclusion/exclusion. (shrink)

I argue that most wild animals live bad lives, and that we should intervene in nature to improve their wellbeing.

The notion of a genetic program has been widely criticized by both biologists and philosophers. But the debate has revolved around a narrow conception of what programs are and how they work, and many criticisms are linked to this same conception. To remedy this, I outline a modern and more apt idea of a program that possesses many of the features critics thought missing from programs. Moving away from over-simplistic conceptions of programs opens the way to a more fruitful interplay (...) of ideas between the complexity of biology and our most complex engineering discipline. (shrink)

Informed consent is a central concept for empirical and theoretical research concerning pregnancy management decisions and is often taken to be one of the more fundamental goals of the profession of genetic counseling. Tellingly, this concept has been seen by disability communities as salutary, despite longstanding critiques made by disability activists, advocates, and scholars concerning practices involved in genetic counseling more generally. In this chapter, we show that the widespread faith in informed consent is misleading and can be detrimental to (...) the practice of genetic counseling as guided by concerns of justice and equity. We proceed in two steps. First, we explain how informed consent is flawed as a practical concept. Second, we show how the inadequacy of informed consent illuminates the animating core of disability critiques of genetic counseling: the issue of ableism. We argue that the problem of ableism cannot be solved with informed consent because it is not merely a problem of information, but also of epistemic schemas. We suggest that what we call critically informed consent is better suited to move genetic counseling from being aware of the problem of ableism to becoming actively anti-ableist. (shrink)

Vitalism was long viewed as the most grotesque view in biological theory: appeals to a mysterious life-force, Romantic insistence on the autonomy of life, or worse, a metaphysics of an entirely living universe. In the early twentieth century, attempts were made to present a revised, lighter version that was not weighted down by revisionary metaphysics: “organicism”. And mainstream philosophers of science criticized Driesch and Bergson’s “neovitalism” as a too-strong ontological commitment to the existence of certain entities or “forces”, over and (...) above the system of causal relations studied by mechanistic science, rejecting the weaker form, organicism, as well. But there has been some significant scholarly “push-back” against this orthodox attitude, notably pointing to the 18th-century Montpellier vitalists to show that there are different historical forms of vitalism, including how they relate to mainstream scientific practice. Additionally, some trends in recent biology that run counter to genetic reductionism and the informational model of the gene present themselves as organicist. Here, we examine some cases of vitalism in the twentieth century and today, not just as a historical form but as a significant metaphysical and scientific model. We argue for vitalism’s conceptual originality without either reducing it to mainstream models of science or presenting it as an alternate model of science, by focusing on historical forms of vitalism, logical empiricist critiques thereof and the impact of synthetic biology on current theorizing of vitalism. (shrink)

The alleged threats to human nature are at the root of many concerns about the use of nanotechnology to extend human health and capabilities. Bu the concept of human nature is illusory, selectively deployed, and does not impose any ethical constraint on human enhancement. Human nature is not only a meaningless concept, a product of our imperfect human cognition and a relic of the idea of a "soul," but, as it is deployed today against human enhancement technologies, it is also (...) a morally offensive, racist concept. The "human-racists" who deploy the concept of human nature are more inclusive than their forebears, but the make the same mistake of tying citizenship and value to biology. By setting aside the concept of human nature, we can affirm the value of the myriad aspects of human existence that we wish to preserve and extend using human enhancement technologies, including whatever genetic capacities and limits we may discover. Human enhancement technologies, such as those that may be enabled by nanotechnology and genetic engineering, enable us to define a new and more dynamic set of human capabilities, and to better achieve many moral virtues, regardless of whether they are part of "human nature" or not. (shrink)

This paper evaluates the claim that it is possible to use nature’s variation in conjunction with retention and selection on the one hand, and the absence of ultimate groundedness of hypotheses generated by the human mind as it knows on the other hand, to discard the ascription of ultimate certainty to the rationality of human conjectures in the cognitive realm. This leads to an evaluation of the further assumption that successful hypotheses with specific applications, in other words heuristics, seem to (...) have a firm footing because they were useful in another context. I argue that usefulness evaluated through adaptation misconstrues the search for truth, and that it is possible to generate talk of randomness by neglecting aspects of a system’s insertion into a larger situation. The framing of the problem in terms of the elimination of unfit hypotheses is found to be unsatisfying. It is suggested that theories exist in a dimension where they can be kept alive rather than dying as phenotypes do. The proposal that the subconscious could suggest random variations is found to be a category mistake. A final appeal to phenomenology shows that this proposal is orphan in the history of epistemology, not in virtue of its being a remarkable find, but rather because it is ill-conceived. (shrink)

The scientific study of living organisms is permeated by machine and design metaphors. Genes are thought of as the ‘‘blueprint’’ of an organism, organisms are ‘‘reverse engineered’’ to discover their func- tionality, and living cells are compared to biochemical factories, complete with assembly lines, transport systems, messenger circuits, etc. Although the notion of design is indispensable to think about adapta- tions, and engineering analogies have considerable heuristic value (e.g., optimality assumptions), we argue they are limited in several important respects. (...) In particular, the analogy with human-made machines falters when we move down to the level of molecular biology and genetics. Living organisms are far more messy and less transparent than human-made machines. Notoriously, evolution is an oppor- tunistic tinkerer, blindly stumbling on ‘‘designs’’ that no sensible engineer would come up with. Despite impressive technological innovation, the prospect of artificially designing new life forms from scratch has proven more difficult than the superficial analogy with ‘‘programming’’ the right ‘‘software’’ would sug- gest. The idea of applying straightforward engineering approaches to living systems and their genomes— isolating functional components, designing new parts from scratch, recombining and assembling them into novel life forms—pushes the analogy with human artifacts beyond its limits. In the absence of a one-to-one correspondence between genotype and phenotype, there is no straightforward way to imple- ment novel biological functions and design new life forms. Both the developmental complexity of gene expression and the multifarious interactions of genes and environments are serious obstacles for ‘‘engi- neering’’ a particular phenotype. The problem of reverse-engineering a desired phenotype to its genetic ‘‘instructions’’ is probably intractable for any but the most simple phenotypes. Recent developments in the field of bio-engineering and synthetic biology reflect these limitations. Instead of genetically engi- neering a desired trait from scratch, as the machine/engineering metaphor promises, researchers are making greater strides by co-opting natural selection to ‘‘search’’ for a suitable genotype, or by borrowing and recombining genetic material from extant life forms. (shrink)

Evolutionary biology is a field currently animated by much discussion concerning its conceptual foundations. On the one hand, we have supporters of a classical view of evolutionary theory, whose backbone is provided by population genetics and the so-called Modern Synthesis (MS). On the other hand, a number of researchers are calling for an Extended Synthe- sis (ES) that takes seriously both the limitations of the MS (such as its inability to incorporate developmental biology) and recent empirical and theoretical research on (...) issues such as evolvability, modularity, and self-organization. In this article, I engage in an in-depth commentary of an influential paper by population geneticist Michael Lynch, which I take to be the best defense of the MS-population genetics position published so far. I show why I think that Lynch’s arguments are wanting and propose a modification of evolutionary theory that retains but greatly expands on population genetics. (shrink)

As a species, we are on the cusp of being able to alter that which makes us uniquely human, our genome. Two new genetic technologies, embryo selection and germline engineering, are either in use today or may be developed in the future. Embryo selection acts to alter the human gene pool, reducing genetic diversity, while germline engineering will have the ability to alter directly the genomes of engineered individuals. Our genome has come to be what it is through an (...) evolutionary process extending over millions of years, a process that has involved exceedingly complex and unpredictable interactions between ourselves or our ancestors and myriad other life forms within Earth's biosphere. In this paper, the ecological imperative, which states that we must not alter the human genome or the collective human genetic inheritance, will be introduced. It will be argued based on ecological principles that embryo selection and germline engineering are unethical and unwise because they will diminish our survivability as a species, will disrupt our relationship with the natural world, and will destroy the very basis of that which makes us human. (shrink)

In 1926, Haldane published an essay titled 'On Being the Right Size' in which he argued that the structure, function, and behavior of an organism are strongly conditioned by the physical forces that exert the greatest impact at the scale at which it exists. This chapter puts Haldane’s insight to work in the context of contemporary cell and molecular biology. Owing to their minuscule size, cells and molecules are subject to very different forces than macroscopic organisms. In a sense, macroscopic (...) and microscopic entities inhabit different “worlds”: the former is ruled by gravity and inertia, whereas the latter is governed by Brownian motion. One implication is that we should be extremely skeptical of models and analogies that seek to explain properties of microscopic entities by appealing to properties of macroscopic ones. Unfortunately, this is precisely what the appeal to engineering metaphors in molecular biology attempts to do. Molecular biologists routinely resort to such metaphors because they are familiar and intuitively intelligible. But if our machines were the size of molecules it would be impossible for them to function the way they do. It follows that we should avoid distorting biological reality by construing it in engineering terms. In this chapter I examine four key metaphors in molecular biology – “genetic program,” “cellular circuitry,” “molecular machine,” and “molecular motor” – and I argue that their deficiencies derive from their neglect of scale. I also try to explain why many biologists today appear to have forgotten the importance of scale that Haldane drew attention to in his essay. I suggest that the reason has to do with the influence of Schrödinger’s argument in 'What is Life?' regarding the stability of the gene. (shrink)

We sometimes feel the presence of a person-like something on a non-biological object, such as a memento from a deceased family member or a well-engineered, human-shaped robot. This feeling—the sense of someone appearing there—has not been extensively investigated by philosophers. In this paper, I employ examples from previous studies, my own experiences, and thought experiments to conduct a philosophical analysis of the mechanism of the emergence of this person-like something by using the concept of an animated persona. This animation (...) process works not only in cases of deceased people and non-biological objects but also in cases of a living, conscious human being. This suggests that the appearance of the other mind on a human body is not necessarily a reflection of that human’s inner self-consciousness but can be considered a personhood that appears, animated by various surrounding factors. I also propose the concept of “the supremacy of surface-ness over behind-ness”. Finally, I categorize the appearance of an animated persona on a human body or an object into eight patterns and compare their characteristics. (shrink)

I claim that differences in the importance attached to economic liberty are more important in debates over the use of genetically modified organisms (GMOs) in agriculture than disagreements about the precautionary principle. I will argue this point by considering a case study: the decision by the U.S. Animal and Plant Health Inspection Service (APHIS) to grant nonregulated status to Roundup Ready soy. I will show that the unregulated release of this herbicide-resistant crop would not be acceptable morally unless one (...) places a very high premium on economic liberty. This is true even if one takes a sound science attitude to unknown risks, rather than a precautionary attitude. I concede that it may not have been within APHIS’s legislative mandate to regulate Roundup Ready soy further, but for those of us who do not put a high premium on economic liberty, this only calls for extending regulatory oversight of GMOs. (shrink)

As technology advances, the demand for innovative instructional materials also increases. As a result, the Department of Education urges teachers to develop instructional materials. This study was conducted at Bulusan National High School, Bulusan, Sorsogon, Philippines SY 2018-2019 which was aimed to develop gamified instructional materials in genetics that would aid in teaching and learning process of grade 12 STEM students. The developed gamified materials were collectively called the GIM in Genetics which is comprised of two parts; namely, Student’s Portfolio (...) and Gamified Lesson Plans. The GIM was anchored on the Teacher’s Guide provided by DepEd. Further, it utilized different game elements, to wit: game mechanics, badges, power cards, scoring system, levels, and leaderboards to deliver innovative teaching strategy and quality education. This paper suggests the development of various innovative teaching strategies and instructional materials as well as its utilization across different fields and subject areas. (shrink)