A novel thermodynamic perspective on natural selection is presented. In the case that life continuity is optimized in an ideal system, where relatively constant and homogeneous selective pressures favour a given competing species, natural selection leads that system to a stationary state of maximum genotypic uniformity of life and maximum sustainable consumption of available energy by life (competitive equilibrium). Structurally and functionally, this optimizing tendency towards competitive equilibrium looks similar to the optimizing tendency towards thermodynamic equilibrium of classical thermodynamics (maximum (...) energetic uniformity and maximum degradation of available energy). The principle of competitive exclusion may thus be conceptually viewed as an ecological manifestation of the second law of (classical) thermodynamics. On the other hand, the novel thermodynamic perspective on natural selection is discussed with regard to the open and nonequilibrium system of nature, where selective pressures vary in space and time. In this case, natural selection can induce diversity instead of uniformity, though an optimizing tendendcy towards maximum sustainable consumption of resources (optimization of life continuity) always remains. Overall, it is concluded that the action of natural selection favours the maximization of the sustainable consumption of energy at the level of individual organism. (shrink)

Ernst Mayr''s contributions to 20th century biology extend far beyond his defense of certain elements in evolutionary theory. At the center of mid-century efforts in American evolutionary studies to build large research communities, Mayr spearheaded campaigns to create a Society for the Study of Evolution and a dedicated journal,Evolution, in 1946. Begun to offset the prominence ofDrosophila biology and evolutionary genetics, these campaigns changed course repeatedly, as impediments appeared, tactics shifted, and compromises built a growing coalition of support. Preserved, however, (...) were designs to balance the community and journal with careful equation of status and explicit partitioning of responsibilities within the working coalition. Choice terms such as cooperation and unity carried a strong political message. Mayr''s editorship ofEvolution provides a superb example of these balancing efforts. The mid-century infrastructural activities described herein also represented aggressive attempts to leverage control across several layers of community. Leaders of these campaigns sought: (1) to promote evolutionary studies as a modernized research discipline and place it at the center of American biology, (2) to promote evolutionary studies within existing disciplines — e.g. systematics, genetics, and paleontology, (3) to foster certain research styles within evolutionary studies, and (4) to emphasize certain solutions to prominent research questions. Throughout, Mayr interjected his priorities, tactics and energy. (shrink)

From its inception Darwinian evolutionary biology has been seen as having a problematic relationship of fact and theory. While the forging of the modern evolutionary synthesis resolved most of these issues for biologists, critics continue to argue that natural selection and common descent are “only theories.” Much of the confusion engendered by the “evolution wars” can be clarified by applying the concept of phenomena, inferred from fact, and explained by theories, thus locating where legitimate dissent may still exist. By setting (...) such analysis in the context of research traditions, it is possible to gain further insight into the complex interplay of facts, phenomena, and theories. Two case studies are explored to assess the value of such approaches, one from within evolutionary biology, the Baldwin effect, and one from outside, intelligent design. (shrink)

Phylogenies are increasingly being used to investigate human history, diversification and cultural evolution. While using phylogenies in this way is not new, new modes of analysis are being applied to inferring history, reconstructing past states, and examining processes of change. Phylogenies have the advantage of providing a way of creating a continuous history of all current populations, and they make a large number of analyses and hypothesis tests possible even when other forms of historical information are patchy or nonexistent. In (...) common with approaches taken in other historical sciences, phylogenetics is a way of reconstructing past and processes using the traces left in the present day. Trees, based on DNA, language, cultural traits, or other evidence, are now sprouting all over the academic landscape. The increasing use of phylogenetic analysis to understand human cultural evolution has been embraced by some, and scorned by others. The purpose of this article is not to review methods and applications of phylogenetic analyses, nor to consider the growing field of cultural phylogenetics, but, more broadly, to explore how we interpret phylogenies as narratives about human diversification. The first half of the article deals with meaning: phylogenies are often interpreted as histories, but a bifurcating tree is at best an abstract representation of history, and its connections to past events and processes is dependent on the data used, the assumptions made in the analysis, and the degree to which nodes in the tree (where one lineage splits into two) can be connected to change and movement in real populations. The second half of the article explores the purpose of phylogenies: a tree does not have to be a literal history of human lineages in order to be useful for investigating processes of human diversification. Phylogenies should not be read as accurate records of history, but as a way of exploring plausible explanations for current patterns of diversity. Phylogenies provide important information that can be used to test ideas about human diversity, and can help to guard against errors of inference arising from statistical artifacts. (shrink)

Although there is no in-principle impediment to an EvoDevo of behavior, such an endeavor is not as straightforward as one might think; many of the key terms and concepts used in EvoDevo are tailored to suit its traditional focus on morphology, and are consequently difficult to apply to behavior. In this light, the application of the EvoDevo conceptual toolkit to the behavioral domain requires the establishment of a set of tractable concepts that are readily applicable to behavioral characters. Here, I (...) begin the type of theoretical work that needs to be undertaken in order to achieve this, focusing in particular on the key concept of “novelty.” Building on existing criteria used for the identification of behavioral homology from behavioral ecology, I develop a set of operational criteria for identifying novelty in the behavioral domain. These criteria provide a conceptual foundation for the study of novelty in behavioral traits. (shrink)

For the first time during evolution of life on this planet, a species has acquired the ability to direct its own genetic destiny. Following 200,000 years of evolution, modern man now has the technologies not only to eradicate genetic disease but also to prolong life and enhance desired physical and mental traits. These technologies include preimplantation diagnosis, cloning, and gene therapy in the germline on native chromosomes or by adding artificial ones. At first glance, we should all be in favor (...) of eliminating genetic diseases and enhancing genetic traits. Evolutionary considerations, however, uncover hidden dangers and suggest caution against the total embracement of such actions. The first major concern is that the genome will never be a completely reliable crystal ball for predicting human phenotypes. This is especially true for predictions concerning the performance of alleles in future generations whose populations might be subjected to different environmental and social challenges. The second, and perhaps more important, concern is that the end result of germline intervention and genetic enhancement will likely lead to the impoverishment of gene variants in the human population and deprive us of one of our most valued assets for survival in the future, our genetic diversity. BioEssays 25:815–821, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

Darwin’s main contribution to modern biology was to make clear that all history of life on earth is dominated by a simple principle, which is usually summarised as 'descent with modification'. However, interpretations about how this modification is produced have been controversial. In light of the data provided by recent studies on molecular biology, developmental biology, genomics, and other biological disciplines we discuss, in this paper, how Darwin's theory may apply to two main 'types' of evolution: that occurring in the (...) prebiotic world and that regarding the acquisition of major key-innovations differentiating higher-taxa, which makes up part of the so-called macroevolution. We argue that these studies show that evolution is a fascinating, complex and multifaceted process, with different mechanisms drivin it on different occasions and in different places. (shrink)

David Lack of Oxford University and V. C. Wynne- Edwards of Aberdeen University were renowned ornithologists with contrasting views of the modern synthesis which deeply influenced their interpretation and explanation of bird behavior. In the 1950's and 60's Lack became the chief advocate of neo-Darwinism with respect to avian ecology, while Wynne- Edwards developed his theory of group selection. Lack 's position was consistent with the developing focus on individual level adaptation, which was a core concept of the modern synthesis. (...) Alternatively, Wynne- Edwards viewed the emphasis on populations as the most important development provided by the modern synthesis. In this paper, I present the development of these two positions and trace their roots in the literature of the synthesis. Through an analysis of Lack 's 1966 critique of Wynne- Edwards I conclude that Wynne- Edwards was, in many ways, justified in his pursuit of group level explanations. (shrink)

Ernst Mayr''s scientific career continues strongly 70 years after he published his first scientific paper in 1923. He is primarily a naturalist and ornithologist which has influenced his basic approach in science and later in philosophy and history of science. Mayr studied at the Natural History Museum in Berlin with Professor E. Stresemann, a leader in the most progressive school of avian systematics of the time. The contracts gained through Stresemann were central to Mayr''s participation in a three year expedition (...) to New Guinea and The Solomons, and the offer of a position in the Department of Ornithology, American Museum of Natural History, beginning in 1931. At the AMNH, Mayr was able to blend the best of the academic traditions of Europe with those of North America in developing a unified research program in biodiversity embracing systematics, biogeography and nomenclature. His tasks at the AMNH were to curate and study the huge collections amassed by the Whitney South Sea Expedition plus the just purchased Rothschild collection of birds. These studies provided Mayr with the empirical foundation essential for his 1942Systematics and the Origin of Species and his subsequent theoretical work in evolutionary biology as well as all his later work in the philosophy and history of science. Without a detailed understanding of Mayr''s empirical systematic and biogeographic work, one cannot possibly comprehend fully his immense contributions to evolutionary biology and his later analyses in the philosophy and history of science. (shrink)

Over the decades, there has been substantial empirical evidence showing that the unity of species cannot be maintained by gene flow. The biological species concept is inconclusive on this point. The suggestion is made that the unity of species is maintained rather by selection constantly spreading new alleles throughout the species, or bygene circulation. There is a lack in conceptual distinction between gene flow and gene circulation which lies at the heart of the problem. The concept of gene circulation also (...) sheds some new light on the problem of typology and on such a broad concept as evolution. A new species definition is proposed. (shrink)

Ernst Mayr''s distinction between ultimate and proximate causes is justly considered a major contribution to philosophy of biology. But how did Mayr come to this philosophical distinction, and what role did it play in his earlier scientific work? I address these issues by dividing Mayr''s work into three careers or phases: 1) Mayr the naturalist/researcher, 2) Mayr the representative of and spokesman for evolutionary biology and systematics, and more recently 3) Mayr the historian and philosopher of biology. If we want (...) to understand the role of the proximate/ultimate distinction in Mayr''s more recent career as a philosopher and historian, then it helps to consider hisearlier use of the distinction, in the course of his research, and in his promotion of the professions of evolutionary biology and systematics. I believe that this approach would also shed light on some other important philosophical positions that Mayr has defended, including the distinction between essentialism: and population thinking. (shrink)

This is the first of a two-part essay on the history of debates concerning the creativity of natural selection, from Darwin through the evolutionary synthesis and up to the present. Here I focus on the mid-late nineteenth century to the early twentieth, with special emphasis on early Darwinism and its critics, the self-styled “mutationists.” The second part focuses on the evolutionary synthesis and some of its critics, especially the “neutralists” and “neo-mutationists.” Like Stephen Gould, I consider the creativity of natural (...) selection to be a key component of what has traditionally counted as “Darwinism.” I argue that the creativity of natural selection is best understood in terms of selection initiating evolutionary change, and selection being responsible for the presence of the variation it acts upon, for example by directing the course of variation. I consider the respects in which both of these claims sound non-Darwinian, even though they have long been understood by supporters and critics alike to be virtually constitutive of Darwinism. (shrink)

This is the second of a two-part essay on the history of debates concerning the creativity of natural selection, from Darwin through the evolutionary synthesis and up to the present. In the first part, I focussed on the mid-late nineteenth century to the early twentieth, with special emphasis on early Darwinism and its critics, the self-styled “mutationists.” The second part focuses on the evolutionary synthesis and some of its critics, especially the “neutralists” and “neo-mutationists.” Like Stephen Gould, I consider the (...) creativity of natural selection to be a key component of what has traditionally counted as “Darwinism.” I argue that the creativity of natural selection is best understood in terms of selection initiating evolutionary change, and selection directing evolutionary change, for example by creating the variation that it subsequently acts upon. I consider the respects in which both of these claims sound non-Darwinian, even though they have long been understood by supporters and critics alike to be virtually constitutive of Darwinism. (shrink)

Pluralisms of various sorts are popular in philosophy of science, including those that imply some scientific concept x should be eliminated from science in favour of a plurality of concepts x1, x2, … xn. This article focuses on influential and representative arguments for such eliminative pluralism about the concept species. The main conclusions are that these arguments fail, that all other extant arguments also fail, and that this reveals a quite general dilemma, one that poses a defeasible presumption against many (...) eliminative pluralisms about various scientific concepts. The article ends by outlining a novel integrative alternative in defence of species. 1) Introduction 2) The species Concept, the Category ‘Species’, and the ‘Species’ Category Problem 3) What Are Eliminative Pluralism about species, and the Arguments for It? 4) Evaluation of Arguments 4.1 Splitting? 4.2 Lumping? 4.3 The eliminative pluralist’s dilemma 5) More General Lessons6Species Cohesion: An Integrative Alternative7Conclusion. (shrink)

Using the Burgess Shale controversies as a case-study, this paper argues that controversies within different domains may interact as to create a situation of "complicated intricacies," where the practicing scientist has to navigate through a context of multiple thought collectives. To some extent each of these collectives has its own dynamic complete with fairly negotiated standards for investigation and explanation, theoretical background assumptions and certain peculiarities of practice. But the intellectual development in one of these collectives may "spill over" having (...) far reaching consequences for the treatment of apparently independent epistemic problems that are subject of investigation in other thought collectives. For the practicing scientist it is necessary to take this complex web of interactions into account in order to be able to navigate in such a situation. So far most studies of academic science have had a tendency to treat the practicing scientist as members of a single (enclosed) thought collective that stands intellectually isolated from other similar entities unless the discipline was in a state of crisis of paradigmatic proportions. The richness and complexity of Burgess Shale debate shows that this encapsulated kind of analysis is not enough. (shrink)

Standard microbial evolutionary ontology is organized according to a nested hierarchy of entities at various levels of biological organization. It typically detects and defines these entities in relation to the most stable aspects of evolutionary processes, by identifying lineages evolving by a process of vertical inheritance from an ancestral entity. However, recent advances in microbiology indicate that such an ontology has important limitations. The various dynamics detected within microbiological systems reveal that a focus on the most stable entities (or features (...) of entities) over time inevitably underestimates the extent and nature of microbial diversity. These dynamics are not the outcome of the process of vertical descent alone. Other processes, often involving causal interactions between entities from distinct levels of biological organisation, or operating at different time scales, are responsible not only for the destabilisation of pre-existing entities, but also for the emergence and stabilisation of novel entities in the microbial world. In this article we consider microbial entities as more or less stabilised functional wholes, and sketch a network-based ontology that can represent a diverse set of processes including, for example, as well as phylogenetic relations, interactions that stabilise or destabilise the interacting entities, spatial relations, ecological connections, and genetic exchanges. We use this pluralistic framework for evaluating (i) the existing ontological assumptions in evolution (e.g. whether currently recognized entities are adequate for understanding the causes of change and stabilisation in the microbial world), and (ii) for identifying hidden ontological kinds, essentially invisible from within a more limited perspective. We propose to recognize additional classes of entities that provide new insights into the structure of the microbial world, namely “processually equivalent” entities, “processually versatile” entities, and “stabilized” entities. (shrink)

Sexual reproduction is a composite, not a singular, phenomenon and as such can be subdivided into a number of componentsi.e. fusion, recombination, fission, and the male-female phenomenon. These components can evolve independently, though any evolutionary change in one component is likely to influence the future evolution of the other components. The ambiguity that surrounds the term ‘sex’ due to a failure to recognise the composite nature of sexual reproduction has led to considerable confusion in past discussions of the evolution of (...) the phenomenon. This paper considers the possible chronological interaction of the components of sexual reproduction both with each other and with the sequence of selective pressures that seem likely to have acted. This chronological approach is used to consider: the origin of sexual reproduction; the evolution of sexual reproduction in the common ancestor of the procaryotes and eucaryotes; the modification of the ancestral system in the procaryote line following the procaryote-eucaryote dichotomy; and the modification of the ancestral system in the eucaryote line up to the origin of the male-female phenomenon.It is suggested that the fusion and recombination of the first living organisms were chronological continuations of the fusion and recombination of complex organic molecules that led up to the origin of life. The evolution of the third major component of sexual reproductioni.e. fission , by definition coincided with the origin of life. Initial selection on the components of sexual reproduction are likely to have been related to the optimum manifestations of size, complexity, diversity, multiplication, and distribution. Resultant early evolutionary trends are likely to have been: selective fusion between more-similar organisms; increase in number of fissions per fusion; and less recombination.The procaryote-eucaryote dichotomy is argued to have evolved in response to the increasing cellular problems of packing and replicating an increasing amount of hereditary material. The evolution of a single circular hereditary organelle in the procaryote line is argued to have led to the loss of total fusion and the specialisation of individuals into either donors or recipients. The donor-recipient phenomenon of procaryotes is directly analogous to the male-female phenomenon of eucaryotes and leads to parallel evolution due to sexual selection in both groups. In the eucaryote line the ancestral mechanism of sexual reproduction is argued to have persisted through, but to have been greatly modified by, the evolution of complex machinery for the handling of multiple hereditary organelles at cell division and reduction division. The evolutionary modification of the ancestral system of sexual reproduction is suggested to have led in eucaryotes to the evolution of: the species phenomenon; allelic recombination; and the male-female phenomenon. (shrink)

No single theory so far proposed gives a wholly satisfactory account of the origin and maintenance of bird-song dialects. This failure is the consequence of a weak comparative literature that precludes careful comparisons among species or studies, and of the complexity of the issues involved. Complexity arises because dialects seem to bear upon a wide range of features in the life history of bird species. We give an account of the principal issues in bird-song dialects: evolution of vocal learning, experimental (...) findings on song ontogeny, dialect descriptions, female and male reactions to differences in dialect, and population genetics and dispersal.We present a synthetic theory of the origin and maintenance of song dialects, one that accommodates most of the different systems reported in the literature. The few data available suggest that large, regional dialect populations are genetically differentiated; this pattern is correlated with reduced dispersal between dialects, assortative mating by females, and male-male exclusion. At the same time, “subdialects” may be formed within regional dialects. Subdialect clusters are usually small and may represent vocal mimicry among a few adjacent territorial males. The relative importance of genetic and social adaptation may contribute to the emergence of subdialects; their distinctiveness may be correlated with the degree of polygyny, for example. Thus, subdialect formation is linked to one theory of the evolution of repertoire size, but data are too fragmentary to examine this idea critically. (shrink)

Different concepts define species at the pattern-level grouping of organisms into discrete clusters, the level of the processes operating within and between populations leading to the formation and maintenance of these clusters, or the level of the inner-organismic genetic and molecular mechanisms that contribute to species cohesion or promote speciation. I argue that, unlike single-level approaches, a multi-level framework takes into account the complex sequences of cause-effect reinforcements leading to the formation and maintenance of various patterns, and allows for revisions (...) and refinements of pattern-based characterizations in light of the gradual elucidation of the causes and mechanisms contributing to pattern formation and maintenance. (shrink)

Sciences able to identify appropriate analytical units for their domain, their natural kinds, have tended to be more progressive. In the biological sciences, evolutionary natural kinds are adaptations that can be identified by their common history of selection for some function. Human brains are the product of an evolutionary history of selection for component systems which produced behaviours that gave adaptive advantage to their hosts. These structures, behaviour production systems, are the natural kinds that psychology seeks. We argue these can (...) be identified deductively by classing behaviour first according to its level of behavioural control. Early animals in our lineage used only reactive production, Vertebrates evolved motivation, and later Primates developed executive control. Behaviour can also be classified by the type of evolutionary benefit it bestows: it can deliver either immediate benefits (food, gametes), improvements in the individual’s position with respect to the world (resource access, social status), or improvements in the ability to secure future benefits (knowledge, skill). Combining history and function implies the existence of seven types of behaviour production systems in human brains responsible for reflexive, instinctual, exploratory, driven, emotional, playful and planned behaviour. Discovering scientifically valid categories of behaviour can provide a fundamental taxonomy and common language for understanding, predicting and changing behaviour, and a way of discovering the organs in the brain––its natural kinds––that are responsible for behaviour. (shrink)

Traditionally, Darwin has been grouped with the functionalists because natural selection (an adaptational mechanism) plays the prominent role in shaping organic form. In this paper, I sketch the dichotomy of functionalism versus structuralism and then argue that Darwin cannot be characterized adequately with this dichotomy. I argue that Darwin can incorporate both causal stories because he makes two important modifications to the traditional metaphysical presuppositions. I then offer some brief reflections on the import of Darwin's causal pluralism for the Philosophy (...) of Science. (shrink)

There are several different ways in which chance affects evolutionary change. That all of these processes are called “random genetic drift” is in part a due to common elements across these different processes, but is also a product of historical borrowing of models and language across different levels of organization in the biological hierarchy. A history of the concept of drift will reveal the variety of contexts in which drift has played an explanatory role in biology, and will shed light (...) on some of the philosophical controversy surrounding whether drift is a cause of evolutionary change. (shrink)

The three processes needed to create life, compartmentalization, metabolism, and information transfer (memory stored in nucleic acids and manipulation operated by proteins) are embedded in organized genome features. The core of life puts together growth and maintenance (which drives survival), while life in context explores and exploits specific niches. Analysis of gene persistence in a large number of genomes shows that the former constitutes the paleome, which recapitulates the three phases of the origin of life: metabolism of small molecules on (...) surfaces, substitution of surfaces by an RNA-world where transfer RNA played a central role, and invention of template mediated information transfer. Colonization of each niche is performed using an almost unlimited set of genes, forming the cenome. The agreement of the paleome structure with a consistent scenario for the origin of life is such that we may consider extant genomes as providing us with an archive of the origin rather than as a palimpsest where most of our past would be irremediably hidden. (shrink)

The species problem is the longstanding puzzle regarding the nature of species. This paper aims to describe how biologists experience little communication breakdown when they have different conceptions of species. For this purpose, I analyze two debates on species and speciation between Guy Bush and Jerry Coyne & H. Allen Orr. Although they have radically different ideas on species, they experience little communication difficulty. I will argue that this is because they implicitly agreed on the referent of the group of (...) organisms being addressed and possible causal factors of the speciation process. This analysis confirms a leading account in the general philosophy of science on the way in which scientists avoid the incommensurability threat. (shrink)