In a recent article in Philosophy of Science Janet Travis [13] seeks to refute the argument for evolutionary progressivism which is based on a series of dominant life forms on the grounds that there is no rigorous definition of that concept. In particular she claims that the definitions formulated by Sir Julian Huxley and George Gaylord Simpson fail adequately to exclude any group of organisms. The concept of dominance is therefore alleged to be meaningless and the argument for progress invalid.

This work takes a stand on whether Wallace should be regarded as co-author of the theory of natural selection alongside Darwin as he is usually considered on behalf of his alleged essential contribution to the conception of the theory. It does so from a perspective unexplored thus far: we will argue for Darwin’s priority based on a rational reconstruction of the theory of natural selection as it appears in the writings of both authors. We show that the theory does not (...) appear in exactly the same manner in the writings of each of its alleged co-discoverers: tough we find the same fundamental elements in both works, even in Darwin’s early texts, we discern a more complex unifying and ramified structure than the one we find in Wallace’s Ternate manuscript. Even when we think the badge of the “Darwin–Wallace” theory is well deserved, the unifying force of Darwin’s version has proved to be one of the keys for the ulterior success of the so-called Darwinian revolution in Biology. (shrink)

Teilhard de Chardin's ideas about the mechanisms of biological evolution are revised and their connections with contemporary theories are reported. Teilhard de Chardin's main contribution is the proposal of a new scientific discipline, geobiology—the science of the biosphere evolving as a whole. The main fields of interest of geobiology are reported, and its relationships with contemporary hypotheses, such as Lovelock's Gaia, are discussed. The consequences of this kind of approach are the parallel evolution described as orthogenesis and the presence of (...) canalization phenomena. These Teilhardian hypotheses are discussed in relation to those of the process structuralists and to the novelties of the molecular evolution of the genome. Conclusions are that the mechanisms discussed by Teilhard are presently taken into consideration by contemporary evolutionists in order to construct a new theory of biological evolution. (shrink)

The T/t locus was a major focus of study by mouse geneticists during the 20th century. In the 70s, as the study of cell surface antigens controlling transplantation antigens was taking off, several laboratories hypothesized that alleles of this locus would control cell surface antigens important for embryonic development. One such antigen, the embryonal carcinoma F9 antigen was said to be an example. Other antigens were described on sperm and embryos that were said to be controlled by alleles at the (...) T/t complex. These findings were later found to be false. The history of the findings and their refutation is described. (shrink)

Group size is a function of relative neocortical volume in nonhuman primates. Extrapolation from this regression equation yields a predicted group size for modern humans very similar to that of certain hunter-gatherer and traditional horticulturalist societies. Groups of similar size are also found in other large-scale forms of contemporary and historical society. Among primates, the cohesion of groups is maintained by social grooming; the time devoted to social grooming is linearly related to group size among the Old World monkeys and (...) apes. To maintain the stability of the large groups characteristic of humans by grooming alone would place intolerable demands on time budgets. It is suggested that (1) the evolution of large groups in the human lineage depended on the development of a more efficient method for time-sharing the processes of social bonding and that (2) language uniquely fulfills this requirement. Data on the size of conversational and other small interacting groups of humans are in line with the predictions for the relative efficiency of conversation compared to grooming as a bonding process. Analysis of a sample of human conversations shows that about 60% of time is spent gossiping about relationships and personal experiences. It is suggested that language evolved to allow individuals to learn about the behavioural characteristics of other group members more rapidly than is possible by direct observation alone. (shrink)

Although classical evolutionary theory, i.e., population genetics and the Modern Synthesis, was already implicitly ‘gene-centred’, the organism was, in practice, still generally regarded as the individual unit of which a population is composed. The gene-centred approach to evolution only reached a logical conclusion with the advent of the gene-selectionist or gene’s eye view in the 1960s and 1970s. Whereas classical evolutionary theory can only work with (genotypically represented) fitness differences between individual organisms, gene-selectionism is capable of working with fitness differences (...) among genes within the same organism and genome. Here, we explore the explanatory potential of ‘intra-organismic’ and ‘intra-genomic’ gene-selectionism, i.e., of a behavioural-ecological ‘gene’s eye view’ on genetic, genomic and organismal evolution. First, we give a general outline of the framework and how it complements the—to some extent—still ‘organism-centred’ approach of classical evolutionary theory. Secondly, we give a more in-depth assessment of its explanatory potential for biological evolution, i.e., for Darwin’s ‘common descent with modification’ or, more specifically, for ‘historical continuity or homology with modular evolutionary change’ as it has been studied by evolutionary developmental biology (evo-devo) during the last few decades. In contrast with classical evolutionary theory, evo-devo focuses on ‘within-organism’ developmental processes. Given the capacity of gene-selectionism to adopt an intra-organismal gene’s eye view, we outline the relevance of the latter model for evo-devo. Overall, we aim for the conceptual integration between the gene’s eye view on the one hand, and more organism-centred evolutionary models (both classical evolutionary theory and evo-devo) on the other. (shrink)

In recent years, several prominent biologists have pointed to the relatively new field of evolutionary developmental biology (EvoDevo) as evidence of an Extended Synthesis in evolutionary biology. More particularly, these biologists claim that theoretical and empirical EvoDevo research is extending the Modern Synthesis framework of evolutionary theory through investigation of evolutionarily important concepts that are not part of the framework developed during the 20th century. To describe the current changes in evolutionary biology as an Extended Synthesis, however, is incorrect. Through (...) review of Extended Synthesis arguments and analysis of the same biological concepts used to support these arguments, I argue that the foundation of the Modern Synthesis framework, theoretical population genetics, faces significant, perhaps insurmountable challenges from the concepts highlighted by EvoDevo research. As the foundation of the Modern Synthesis framework will require considerable remodeling—if possible—in light of the concepts emphasized by EvoDevo, it is incorrect to describe the ongoing changes in evolutionary biology as an Extended Synthesis. (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)

In the 1940s, the ‘modern synthesis’ (MS) of Darwinism and genetics cast genetic mutation and recombination as the source of variability from which environmental events naturally select the fittest, such ‘natural selection’ constituting the cause of evolution. Recent biology increasingly challenges this view by casting genes as followers and awarding the leading role in the genesis of adaptations to the agency and plasticity of developing phenotypes—making natural selection a consequence of other causal processes. Both views of natural selection claim to (...) capture the core of Darwin’s arguments in On the Origin of Species. Today, historians largely concur with the MS’s reading of Origin as a book aimed to prove natural selection the cause (vera causa) of adaptive change. This paper finds the evidence for that conclusion wanting. I undertake to examine the context and meaning of all Darwin’s known uses of the phrase vera causa, documenting in particular Darwin’s resistance to the pressure to prove natural selection a vera causa in letters written early in 1860. His resistance underlines the logical dependence of natural selection, an unobservable phenomenon, on the causal processes producing the observable events captured by the laws of inheritance, variation, and the struggle for existence, established in Chapters 1–3 of Origin. (shrink)

Between 1946 and 1960, a new phenomenon emerged in the field of bacteriology. "Bacterial sex," as it was called, revolutionized the study of genetics, largely by making available a whole new class of cheap, fast-growing, and easily manipulated organisms. But what was "bacterial sex?" How could single-celled organisms have "sex" or even be sexually differentiated? The technical language used in the scientific press -- the public and inalienable face of 20th century science -- to describe this apparently neuter organism was (...) explicit: the cells "copulated," had "intimate contract," "conjugal unions," and engaged in "ménage à trois" relationships. And yet, to describe bacteria as sexually reproducing organisms, the definition of sex itself had to change. Despite manifold contradictions and the availability of alternative language, the notion of sexually active (even promiscuous) single-celled organisms has persisted, even into contemporary textbooks on cell biology and genetics. In this paper I examine the ways in which bacteria were brought into the genetic fold, sexualized, and given gender; I also consider the issues underlying the durability of "bacterial sex.". (shrink)

Common folks “have” emotions and talk to others; and sometimes they make “their” emotions the topic of such talk. The emotions seem to be “theirs,” since they can be conceived of as private states ; and they can be topicalized, because we seem to be able to attribute or lend a conventionalized public form to some inner state or event. This is the way much of our folk-talk and folk-thinking about emotions, the expression thereof, the role of language in these (...) expressions, and communication in general are organized. However, as we have shown, such talk serves the purpose of communicating effectively and reaching mutual understanding. (shrink)