Discussion of Darwinian evolutionary theory by philosophers has gone through a number of historical phases, from indifference (in the first hundred years), to criticism (in the 1960s and 70s), to enthusiasm and expansionism (since about 1980). This paper documents these phases and speculates about what, philosophically speaking, underlies them. It concludes with some comments on the present state of the evolutionary debate, where rapid and important changes within evolutionary theory may be passing by unnoticed by philosophers.

In these notes, unadorned page numbers under 350 refer to Dennett (1987) - The Intentional Stance, hereafter referred to as Stance - and ones over 495 refer to Dennett (1988) - mostly to material by him but occasionally to remarks of his critics. Since the notes will focus on disagreements, I should say now that I am in Dennett’s camp and am deeply in debt to his work in the philosophy of mind, which I think is wider, deeper, more various (...) and more fruitful than mine or anyone else’s. Still, I have some ideas and emphases that I think he could profit from. In the final chapter of Stance Dennett compares his work with that of several others, including me. He sees me as having a position like his, the main difference being that I think (as he doesn’t) that our attributions of mental content can always be highly determinate (pp. 347f). In fact, there are differences between us but this isn’t one of them. I want to get this straight, so as to clear the decks for the positive points I am going to make. There is some indeterminacy and there could be lots of it; Dennett’s case for that is unanswerable. As for how much there actually is: I don’t know and don’t even suspect; there is simply no declared issue between Dennett and myself on that. Nor do we disagree on a related matter. If there is no evidence that settles whether the animal believes that P or believes that Q, should we say that nevertheless one of these is right, and it’s just that we can’t know which it is? Dennett says No. I perfectly agree. (shrink)

This is a theoretical paper. A little theory goes a long way in history, for me; but it is good to collect as much as is feasible in one paper, so that gaps and inconsistencies can be noticed. I use ‘theory’ in the definite sense of a set of hypothetical statements such that deductions can be made and compared with data, facts, or generalizations obtained in some other way than as derivation from theory. Deductions need not always be rigorous, and (...) there may be two or more ‘solutions’ obtainable, of which the scientist may choose one and discard the rest . I am ignoring the differences between propositions, demonstrations, problems, and the like. Actually there must always be several statements, including rules of procedure, in the set; but often many are assumed and only the new or controversial one is stated as ‘the’ hypothesis of Mr X. (shrink)

An examination of the post-Darwinian history of biological taxonomy reveals an implicit assumption that the definitions of taxon names consist of lists of organismal traits. That assumption represents a failure to grant the concept of evolution a central role in taxonomy, and it causes conflicts between traditional methods of defining taxon names and evolutionary concepts of taxa. Phylogenetic definitions of taxon names (de Queiroz and Gauthier 1990) grant the concept of common ancestry a central role in the definitions of taxon (...) names and thus constitute an important step in the development of phylogenetic taxonomy. By treating phylogenetic relationships rather than organismal traits as necessary and sufficient properties, phylogenetic definitions remove conflicts between the definitions of taxon names and evolutionary concepts of taxa. The general method of definition represented by phylogenetic definitions of clade names can be applied to the names of other kinds of composite wholes, including populations and biological species. That the names of individuals (composite wholes) can be defined in terms of necessary and sufficient properties provides the foundation for a synthesis of seemingly incompatible positions held by contemporary individualists and essentialists concerning the nature of taxa and the definitions of taxon names. (shrink)

Biologists and philosophers that debate the existence of the species category fall into two camps. Some believe that the species category does not exist and the term 'species' should be eliminated from biology. Others believe that with new biological insights or the application of philosophical ideas, we can be confident that the species category exists. This paper offers a different approach to the species problem. We should be skeptical of the species category, but not skeptical of the existence of those (...) taxa biologists call 'species.' And despite skepticism over the species category, there are pragmatic reasons for keeping the word 'species.' This approach to the species problem is not new. Darwin employed a similar strategy to the species problem 150 years ago. (shrink)

In addition to the distinction between species as a category and speciesas a taxon, the word species is ambiguous in a very different butequally important way, namely the temporal distinction between horizontal andvertical species. Although often found in the relevant literature, thisdistinction has thus far remained vague and undefined. In this paper the use ofthe distinction is explored, an attempt is made to clarify and define it, andthen the relation between the two dimensions and the implications of thatrelation are examined. (...) Using Darwin's analogy of language evolution forspeciesevolution, and by appealing to a major change in the conception of languagebetween 19th- and 20th-century linguistics, it is argued that the horizontaldimension has priority (pragmatic, epistemological, logical, and ontological)over the vertical dimension. This has immense ramifications for the modernspecies problem. Fundamentally, it favors horizontal species concepts oververtical ones. In so doing it places species realism on a much more securefoundation and largely undercuts species pluralism. In addition it raises aserious problem for the increasingly popular family of phylogenetic speciesconcepts, which generally suffer from a dimensionality confusion. However,thereis a recent trend within this family that attempts to restore the priority ofthe horizontal dimension. It is concluded that this trend should be affirmedandthat the species-as-individuals view should be abandoned. (shrink)

It is often claimed that one of Darwin''s chief accomplishments was to provide biology with a non-teleological explanation of adaptation. A number of Darwin''s closest associates, however, and Darwin himself, did not see it that way. In order to assess whether Darwin''s version of evolutionary theory does or does not employ teleological explanation, two of his botanical studies are examined. The result of this examination is that Darwin sees selection explanations of adaptations as teleological explanations. The confusion in the nineteenth (...) century about Darwin''s attitude to teleology is argued to be a result of Darwin''s teleological explanations not conforming to either of the dominant philosophical justifications of teleology at that time. Darwin''s explanatory practices conform well, however, to recent defenses of the teleological character of selection explanations. (shrink)

Darwin''s biology was teleological only if the term teleology is defined in a manner that fails to recognize his contribution to the metaphysics and epistemology of modern science. His use of teleological metaphors in a strictly teleonomic context is irrelevant to the meaning of his discourse. The myth of Darwin''s alleged teleology is partly due to misinterpretations of discussions about whether morphology should be a purely formal science. Merely rejecting such notions as special creation and vitalism does not prevent the (...) pernicious effects of teleological reasoning, even at the present time. (shrink)

Since the 1970s, there has been a tremendous amount of literature on Ghiselin's proposal that species are individuals. After recalling the origins and stakes of this thesis in contemporary evolutionary theory, I show that it can also be found in the writings of the French naturalist Buffon in the 18th Century. Although Buffon did not have the conception that one species could be derived from another, there is an interesting similarity between the modern argument and that of Buffon regarding the (...) individuality of species. The analogy is strong enough to force us to recognize that genuine evolutionary (or Darwinian) questions might be of secondary importance in the discussion. In consequence, the third section of the paper proposes an alternative schema for the logical structure of the Darwinian concept of species. Darwin distinguished the problem of the designation of a concrete species, and the problem of its signification of species within his theory of descent? The resulting notion of species involves a logical structure based on the fusion of the logical operations of classification and ordering. The difficulty — and interest — is that this interpretation of species does not entail any precise operational definition of species; it can only tell us what the ultimate signification of classification is within the theory of descent with modification through natural selection. (shrink)

Recent historiography of 19th century biology supports the revision of two traditional doctrines about the history of biology. First, the most important and widespread biological debate around the time of Darwin was not evolution versus creation, but biological functionalism versus structuralism. Second, the idealist and typological structuralist theories of the time were not particularly anti-evolutionary. Typological theories provided argumentation and evidence that was crucial to the refutation of Natural Theological creationism. The contrast between functionalist and structuralist approaches to biology continues (...) today, and the historical misunderstanding of 19th century typological biology may be one of its effects. This historical case can shed light on current controversies regarding the relevance of developmental biology to evolution. (shrink)

Ernst Mayr has argued that Darwinian theory discredited essentialist modes of thought and replaced them with what he has called "population thinking". In this paper, I characterize essentialism as embodying a certain conception of how variation in nature is to be explained, and show how this conception was undermined by evolutionary theory. The Darwinian doctrine of evolutionary gradualism makes it impossible to say exactly where one species ends and another begins; such line-drawing problems are often taken to be the decisive (...) reason for thinking that essentialism is untenable. However, according to the view of essentialism I suggest, this familiar objection is not fatal to essentialism. It is rather the essentialist's use of what I call the natural state model for explaining variation which clashes with evolutionary theory. This model implemented the essentialist's requirement that properties of populations be defined in terms of properties of member organisms. Requiring such constituent definitions is reductionistic in spirit; additionally, evolutionary theory shows that such definitions are not available, and, moreover, that they are not needed to legitimize population-level concepts. Population thinking involves the thesis that population concepts may be legitimized by showing their connections with each other, even when they are not reducible to concepts applying at lower levels of organization. In the paper, I develop these points by describing Aristotle's ideas on the origins of biological variation; they are a classic formulation of the natural state model. I also describe how the development of statistical ideas in the 19th century involved an abandoning of the natural state model. (shrink)

Doren Recker has criticized the prevailing accounts of Darwin's argument for the theory of natural selection in the Origin of Species. In this note I argue that Recker fails to distinguish between a deductive short argument for the principle of natural selection, and a non-deductive, long argument which aims at establishing that the principle has explanatory power in the various domains of application. I shall try to show that the semantic view of theories, especially in its structuralist form, makes it (...) easy to distinguish between the two arguments and to explain how Darwin's long argument counts as one argument. I also raise a question about Recker's views on Darwin's mid-Victorian background, arguing that Newton's First Rule of Reasoning was not just a constraint on hypotheses involving unobservables, but a general request to keep conjecture and certainty apart. (shrink)

The philosophical or metaphysical architecture of Darwin's theory of evolution by natural selection is analyzed and diflussed. It is argued that natural selection was for Darwin a paradigmatic case of a natural law of change — an exemplar of what Ghiselin (1969) has called selective retention laws. These selective retention laws lie at the basis of Darwin's revolutionary world view. In this essay special attention is paid to the consequences for Darwin's concept of species of his selective retention laws. Although (...) Darwin himself explicity supported a variety of nominalism, implicit in the theory of natural selection is a solution to the dispute between nominalism and realism. It is argued that, although implicit, this view plays a very important role in Darwin's theory of natural selection as the means for the origin of species. It is in the context of these selective retention laws and their philosophical implications that Darwin's method is appraised in the light of recent criticisms, and the conclusion drawn that he successfully treated some philosophical problems by approaching them through natural history. Following this an outline of natural selection theory is presented in which all these philosophical issues are highlighted. (shrink)

Biological species have been treated traditionally as spatiotemporally unrestricted classes. If they are to perform the function which they do in the evolutionary process, they must be spatiotemporally localized individuals, historical entities. Reinterpreting biological species as historical entities solves several important anomalies in biology, in philosophy of biology, and within philosophy itself. It also has important implications for any attempt to present an "evolutionary" analysis of science and for sciences such as anthropology which are devoted to the study of single (...) species. (shrink)

Species pluralism gives us reason to doubt the existence of the species category. The problem is not that species concepts are chosen according to our interests or that pluralism and the desire for hierarchical classifications are incompatible. The problem is that the various taxa we call 'species' lack a common unifying feature.

Most biologists use the Linnaean system for constructing classifications of the organic world. The Linnaean system, however, has lost its theoretical basis due to the shift in biology from creationist and essentialist tenets to evolutionary theory. As a result, the Linnaean system is both cumbersome and ontologically vacuous. This paper illustrates the problems facing the Linnaean system, and ends with a brief introduction to an alternative approach to biological classification.

Ethologists and others studying animal behavior in a spirit are in need of a descriptive language and method that are neither anachronistically bound by behaviorist scruples nor prematurely committed to particular Just such an interim descriptive method can be found in intentional system theory. The use of intentional system theory is illustrated with the case of the apparently communicative behavior of vervet monkeys. A way of using the theory to generate data - including usable, testable data - is sketched. The (...) underlying assumptions of this approach can be seen to ally it directly with theorizing in evolutionary biology, which has recently come under attack from Stephen Gould and Richard Lewontin, who castigate it as the Their arguments, which are strongly analogous to B. F, Skinner's arguments against point to certain pitfalls that attend the careless exercise of such thinking (and rival varieties of thinking as well), but do not constitute a fundamental objection to either adaptationist theorizing or its cousin, intentional system theory. (shrink)

No response that was not as long and intricate as the two commentaries combined could do justice to their details, so what follows will satisfy nobody, myself included. I will concentrate on one issue discussed by both commentators: the relationship between evolution and teleological (or intentional) explanation. My response, in its brevity, may have just one virtue: it will confirm some of the hunches (or should I say suspicions) that these and other writers have entertained about my views. For more (...) closely argued defenses of my points, see Dennett 1990a,b,c; 1991a,b. (shrink)

The rise of mechanistic science in the seventeenth century helped give rise to a heated debate about whether teleology—the appearance of purposive activity in life and in mind—could be naturalized. At issue here were both what is meant by “teleology” as well as what is meant “nature”. I shall examine a specific episode in the history of this debate in the twentieth century with the rise of cybernetics: the science of seemingly “self-controlled” systems. Against cybernetics, Hans Jonas argued that cybernetics (...) failed as a naturalistic theory of teleology and that the reality of teleology is grounded in phenomenology, not in scientific explanations. I shall argue that Jonas was correct to criticize cybernetics but that contemporary work in biological organization succeeds where cybernetics failed. I will then turn to contemporary uses of Jonas’s phenomenology in enactivism and argue that Jonas’s phenomenology should be avoided by enactivism as a scientific research program, but that it remains open whether enactivism as a philosophy of nature should also avoid Jonas. (shrink)

The aim of this paper is to explain why, while Charles Darwin was well recognized as a scientific leader of his time, Claude Bernard never really regarded Darwinism as a scientific theory. The lukewarm reception of Darwin at the Académie des Sciences of Paris and his nomination to a chair only after 8 years contrasts with his prominence, and Bernard’s attitude towards Darwin’s theory of species evolution belongs to this French context. Yet we argue that Bernard rejects the scientific value (...) of Darwinian principles mainly for epistemological reasons. Like Darwin, Bernard was interested in hereditary processes, and planned to conduct experiments on these processes that could lead to species transformation. But the potential creation of new forms of life would not vindicate Darwinism since biologists can only explain the origin of morphotypes and morphological laws by the means of untestable analogies. Because it can be the object neither of experiments nor of any empirical observation, phylogeny remains out of science’s scope. Around 1878 Bernard foresaw a new general physiology based on the study of protoplasm, which he saw as the agent of all basic living phenomena. We will analyze why Bernard regarded Darwinism as part of metaphysics, yet still referred to Darwinians in his latter works in 1878. Basically, the absence of a scientific reception of Darwinism in Bernard's work should not obscure its philosophical reception, which highlights the main principles of Bernard’s epistemology. (shrink)

In the Origin of Species (1859), Darwin argued that his revolutionary theory of evolution by natural selection represented a significant breakthrough in the understanding of instinctive behaviour. However, many aspects in the development of his thinking on behavioural phenomena indicate that the explanation of this particular organic feature was by no means an easy one, but that it posed an authentic challenge – something that Darwin himself always recognized. This paper explores Darwin’s treatment of instincts within his theory of natural (...) selection. Particular attention is given to elucidate how he tackled the difficulties of explaining instincts as evolving mental features. He had to explain and demonstrate its inheritance, variation, and gradual accumulation within populations. The historical and philosophical aspects of his theory are highlighted, as well as his study of the case in which the explanation of instincts represented a ‘special difficulty’; that is, the sterile castes of social insects. (shrink)

Algunos aspectos de La expresión de las emociones de Charles Darwin pueden resultar intrigantes, pues, en la explicación de cómo tales expresiones se originan, Darwin casi nunca apela a la selección natural. En cambio, apela principalmente a la idea de que movimientos voluntarios se asocian a emociones, volviéndose por hábito innatos e involuntarios al heredarse a la descendencia. Si bien Darwin da varias razones para defender esta explicación, en este trabajo trataré de mostrar que, si se entiende el libro sobre (...) las expresiones en relación con los objetivos explícitos e implícitos de El origen del hombre (libro del cual originalmente iba a ser un capítulo), el asunto se entiende mejor. En particular, resulta interesante la tesis que Desmond y Moore plantean respecto a la importancia de los ideales antiesclavistas de Darwin a la hora del tratamiento de las razas. Defenderé en este trabajo que el enfoque de Desmond y Moore puede extenderse al libro acerca de las expresiones. Específicamente, estableceré vínculos entre la explicación del origen de las razas y la explicación del origen del rubor. (shrink)

Abstract One of the most important things that the Darwinian revolution affected is the previous teleological thinking. In particular, the attribution of functions to various entities of the natural world with explanatory pretensions. In this change, his theory of natural selection played an important role. We all agree on that, but the diversity and heterogeneity of the answers that try to explain what Darwin did exactly with functional biology are overwhelming. In this paper I will try to show how Darwin (...) modified previous functional biology. Pre-Darwinian naturalists did not hesitate to attribute functions in which, for example, the traits of one species were in the service of other species. I will try to show that this has consequences on the discussion regarding the nature of functional language, since the main approaches, the systemic and the etiological, do not adequately account for these changes and therefore do not account for the way functional biology regulates the kind of legitimate functions. I will outline a possible new solution to this problem: appropriate functional attributions in Darwinian functional biology could be regulated by a theory or a set of laws that provide the criteria for determining its fundamental concepts. -/- Resumen: Una de las cosas más importantes a las que la revolución darwiniana afectó es el pensamiento teleológico previo. En particular, la atribución de funciones a diversas entidades del mundo natural con pretensiones explicativas. En este cambio, su teoría de la selección natural desempeñó un papel importante. Todos estamos de acuerdo en ello, pero la diversidad y heterogeneidad de las respuestas que tratan de explicar lo que Darwin hizo exactamente con la biología funcional son abrumadoras. En este artículo intentaré mostrar cómo Darwin modificó la biología funcional anterior. Los naturalistas predarwinianos no dudaban en atribuir funciones en las que, por ejemplo, los rasgos de una especie estaban al servicio de otras especies. Intentaré mostrar que esto tiene consecuencias en la discusión sobre la naturaleza del lenguaje funcional, pues los principales enfoques, el sistémico y el etiológico, no dan cuenta adecuadamente de estos cambios y, por tanto, no dan cuenta de la forma en que la biología funcional regula el tipo de funciones legítimas. Esbozaré una posible nueva solución a este problema: las atribuciones funcionales apropiadas en la biología funcional darwiniana podrían estar reguladas por una teoría o un conjunto de leyes que proporcionen los criterios para determinar sus conceptos fundamentales. -/- . (shrink)

La constatación de que nuestro universo está constituido de unos y los mismos elementos materiales en cualquier lugar en que podamos observarlo nos lleva directamente a la postulación de un único principio y causa del único proceso universal al que se debe cuanto existe. Y en ese trance parece inevitable preguntar: ¿cómo ha surgido Todo? Todo, aquí, significa cuanto hay; sin excepción alguna. Esta visión puramente física del Universo puede denominarse naturalismo universal, entendiendo el término naturalismo como traducción del término (...) aristotélico physis en su célebre definición. (shrink)

These preprints were automatically compiled into a PDF from the collection of papers deposited in PhilSci-Archive in conjunction with the PSA 2018.

There is a fairly long-standing distinction between what are called the ideographic as opposed to nomothetic sciences. The nomothetic sciences, such as physics, offer explanations in terms of the laws and regular operations of nature. The ideographic sciences, such as natural history, cast explanations in terms of narratives. This article offers an account of what is involved in offering an explanatory narrative in the historical sciences. I argue that narrative explanations involve two chief components: a possibility space and an explanatory (...) causal mechanism. (shrink)

In response to Quinn we identify cladistics to be about natural classifications and their discovery and thereby propose to add an eighth cladistic definition to Quinn’s list, namely the systematist who seeks to discover natural classifications, regardless of their affiliation, theoretical or methodological justifications.

Many standard philosophical accounts of scientific practice fail to distinguish between modeling and other types of theory construction. This failure is unfortunate because there are important contrasts among the goals, procedures, and representations employed by modelers and other kinds of theorists. We can see some of these differences intuitively when we reflect on the methods of theorists such as Vito Volterra and Linus Pauling on the one hand, and Charles Darwin and Dimitri Mendeleev on the other. Much of Volterra's and (...) Pauling's work involved modeling; much of Darwin's and Mendeleev's did not. In order to capture this distinction, I consider two examples of theory construction in detail: Volterra's treatment of post-WWI fishery dynamics and Mendeleev's construction of the periodic system. I argue that modeling can be distinguished from other forms of theorizing by the procedures modelers use to represent and to study real-world phenomena: indirect representation and analysis. This differentiation between modelers and non-modelers is one component of the larger project of understanding the practice of modeling, its distinctive features, and the strategies of abstraction and idealization it employs. (shrink)

Recent Darwin scholarship has provided grounds for recognising the Origin as a literary as well as a scientific achievement. While Darwin was an acute observer, a gifted experimentalist and indefatigable theorist, this essay argues that it was also crucial to his impact that the Origin transcended the putative divide between the scientific and the literary. Analysis of Darwin’s development as a writer between his journal-keeping on HMS Beagle and his construction of the Origin argues the latter draws on the pattern (...) of the Romantic or Kantian sublime. The Origin repeatedly uses strategies which challenge the natural-theological appeal to the imagination in conceiving nature. Darwin’s sublime coaches the Origin’s readers into a position from which to envision nature that reduces and contains its otherwise overwhelming complexity. As such, it was Darwin’s literary achievement that enabled him to fashion a new ‘habit of looking at things in a given way’ that is the centrepiece of the scientific revolution bearing his name. (shrink)

This paper attempts a critical examination of scholarly understanding of the historical event referred to as "the Darwinian Revolution." In particular, it concentrates on some of the major scholarly works that have appeared since the publication in 1979 of Michael Ruse's "The Darwinian Revolution: Nature Red in Tooth and Claw." The paper closes by arguing that fruitful critical perspectives on what counts as this event can be gained by locating it in a range of historiographic and disciplinary contexts that include (...) the emergence of the discipline of evolutionary biology, the 1959 Darwin centenary, and the maturation of the discipline of the history of science. Broader perspectives on something called the "Darwinian Revolution" are called for that include recognizing that it does not map a one-to-one correspondence with the history of evolution, broadly construed. (shrink)

William Sharp Macleay developed the quinarian system of classification in his Horæ Entomologicæ, published in two parts in 1819 and 1821. For two decades, the quinarian system was widely discussed in Britain and influenced such naturalists as Charles Darwin, Richard Owen, and Thomas Huxley. This paper offers the first detailed account of Macleay’s development of the quinarian system. Macleay developed his system under the shaping influence of two pressures: (1) the insistence by followers of Linnaeus on developing artificial systems at (...) the expense of the natural system and (2) the apparent tension between the continuity of organic nature and the failure of linear classification schemes (which continuity seemed to require). Against what he perceived as dogmatic indolence on the part of the Linnaeans, Macleay developed a philosophy of science in which hypotheses that exceeded the available evidence should be proposed and subjected to severe tests. He also developed a novel comparative anatomical methodology, the method of variation, to aid in his search for the natural system. Using this method, he developed an intricate system that showed how organic nature could be continuous without being linear. A failure to appreciate these facets of Macleay’s thought has led to several misunderstandings of him and his work, most notably that he was an idealist. These misunderstandings are here rebutted. (shrink)

Some adaptationist explanations are regarded as maximally solid and others fanciful just-so stories. Just-so stories are explanations based on very little evidence. Lack of evidence leads to circular-sounding reasoning: “this trait was shaped by selection in unseen ancestral populations and this selection must have occurred because the trait is present.” Well-supported adaptationist explanations include evidence that is not only abundant but selected from comparative, populational, and optimality perspectives, the three adaptationist subdisciplines. Each subdiscipline obtains its broad relevance in evolutionary biology (...) via assumptions that can only be tested with the methods of the other subdisciplines. However, even in the best-supported explanations, assumptions regarding variation, heritability, and fitness in unseen ancestral populations are always present. These assumptions are accepted given how well they would explain the data if they were true. This means that some degree of “circularity” is present in all evolutionary explanations. Evolutionary explanation corresponds not to a deductive structure, as biologists usually assert, but instead to ones such as abduction or induction. With these structures in mind, we show the way to a healthier view of “circularity” in evolutionary biology, and why integration across the comparative, populational, and optimality approaches is necessary. (shrink)

In 1880, Charles Darwin publishedThe Power of Movement in Plants, a heavy volume of nearly six hundred pages in which he presented the results of many years of experiments conducted with his son Francis on the reaction of plants to the influence of light and gravity. His results contradicted the observations and explanations of the same phenomena offered by the German plant physiologist Julius Sachs in his influentialLehrbuch der Botanik(1868, English translation 1875). Darwin wished rather to ‘convert him than any (...) other half-dozen botanies put together’. Sachs, however, regarded Darwin's work with contempt. Taking up the topic in hisVorlesungen über Pflanzenphysiologiein 1882 and taking issue especially with Darwin's experiments on the movement of root radicles in reaction to gravity, he remarked sharply: In such experiments with roots not only is great precaution necessary, but also the experience of years and extensive knowledge of vegetable physiology, to avoid falling into errors, as did Charles Darwin and his son Francis, who, on the basis of experiments which were unskilfully made and improperly explained, came to the conclusion, as wonderful as it was sensational, that the growing point of the root, like the brain of an animal, dominates the various movements in the root. (shrink)

Patterns in the data on human sexuality support the hypothesis that the bases of sexual emotions are products of natural selection. Most generally, the universal existence of laws, rules, and gossip about sex, the pervasive interest in other people's sex lives, the widespread seeking of privacy for sexual intercourse, and the secrecy that normally permeates sexual conduct imply a history of reproductive competition. More specifically, the typical differences between men and women in sexual feelings can be explained most parsimoniously as (...) resulting from the extraordinarily different reproductive opportunities and constraints males and females normally encountered during the course of evolutionary history. Men are more likely than women to desire multiple mates; to desire a variety of sexual partners; to experience sexual jealousy of a spouse irrespective of specific circumstances; to be sexually aroused by the sight of a member of the other sex; to experience an autonomous desire for sexual intercourse; and to evaluate sexual desirability primarily on the bases of physical appearance and youth.The evolutionary causes of human sexuality have been obscured by attempts to find harmony in natural creative processes and human social life and to view sex differences as complementary. The human female's capacity for orgasm and the loss of estrus, for example, have been persistently interpreted as marriage-maintaining adaptations. Available evidence is more consistent with the view that few sex differences in sexuality are complementary, that many aspects of sexuality undermine marriage, and that sexuality is less a unifying than a divisive force in human affairs. (shrink)

Classifying is a fundamental operation in the acquisition of knowledge. Taxonomic theory can help students of cognition, evolutionary psychology, ethology, anatomy, and sociobiology to avoid serious mistakes, both practical and theoretical. More positively, it helps in generating hypotheses useful to a wide range of disciplines. Composite wholes, such as species and societies, are “individuals” in the logical sense, and should not be treated as if they were classes. A group of analogous features is a natural kind, but a group of (...) homologous features is not. Imposing hypotheses justified only on the basis of nominalist, realist, phenomenalist, or conceptualist metaphysics upon the neurophysiology of organisms or upon the causes of behavior exemplifies the “psychologist's fallacy” of William James. Levels should be distinguished from their members and from classes of levels, and the ontological status of entities ranked at levels should be made clear. It is important not to confuse such categories as substance and process with one another. Several genetical terms, such as “gene” and chromosome,” are even more equivocal than has been realized. Discussions about units of selection, behavior, and thinking suffer from the ambiguity of a “unit of” an entity. An important source of misunderstanding about natural selection is the habit of treating it as an “agent”: in an important sense, natural selection does not “act” at all. (shrink)

Contemporary mate preferences can provide important clues to human reproductive history. Little is known about which characteristics people value in potential mates. Five predictions were made about sex differences in human mate preferences based on evolutionary conceptions of parental investment, sexual selection, human reproductive capacity, and sexual asymmetries regarding certainty of paternity versus maternity. The predictions centered on how each sex valued earning capacity, ambition— industriousness, youth, physical attractiveness, and chastity. Predictions were tested in data from 37 samples drawn from (...) 33 countries located on six continents and five islands. For 27 countries, demographic data on actual age at marriage provided a validity check on questionnaire data. Females were found to value cues toresource acquisitionin potential mates more highly than males. Characteristics signalingreproductive capacitywere valued more by males than by females. These sex differences may reflect different evolutionary selection pressures on human males and females; they provide powerful cross-cultural evidence of current sex differences in reproductive strategies. Discussion focuses on proximate mechanisms underlying mate preferences, consequences for human intrasexual competition, and the limitations of this study. (shrink)