This paper analyzes biological and scientific discourses about the racial composition of the Brazilian population, between 1832 and 1911. The first of these dates represents Darwin’s first arrival in the South-American country during his voyage on H.M.S. Beagle. The study ends in 1911, with the celebration of the First universal Races congress in London, where the Brazilian physical anthropologist J.B. Lacerda predicted the complete extinction of black Brazilians by the year 2012. Contemporary European and North-American racial theories had a profound (...) influence in Brazilian scientific debates on race and miscegenation. These debates also reflected a wider political and cultural concern, shared by most Brazilian scholars, about the future of the Nation. With few known exceptions, Brazilian evolutionists, medical doctors, physical anthropologists, and naturalists, considered that the racial composition of the population was a handicap to the commonly shared nationalistic goal of creating a modern and progressive Brazilian Republic. (shrink)

Sightings of the revolutionary comet that appeared in the skies of evolutionary biology in 1976—the selfish gene—date back to the 19th and early 20th centuries. It became generally recognized that genes were located on chromosomes and compete with each other in a manner consistent with the later appellation “selfish.” Chromosomes were seen as disruptable by the apparently random “cut and paste” process known as recombination. However, each gene was only a small part of its chromosome. On a statistical basis a (...) gene should escape disruption for many generations. This led George Williams and Richard Dawkins to a new definition of the gene, differing from conventional biochemical definitions in that there were no consistent genic boundaries. There had been no previous sightings of another revolutionary, albeit less verbally spectacular, comet that appeared in 1975—the homostability principle of Akiyoshi Wada. Each gene has a base composition “accent” that distinguishes it from its neighbors. We now see that recombination can be triggered by the shift in base composition at genic boundaries. Hence, the Williams-Dawkins definition approaches the conventional definitions. (shrink)

Sightings of the revolutionary comet that appeared in the skies of evolutionary biology in 1976—the selfish gene—date back to the 19th and early 20th centuries. It became generally recognized that genes were located on chromosomes and compete with each other in a manner consistent with the later appellation “selfish.” Chromosomes were seen as disruptable by the apparently random “cut and paste” process known as recombination. However, each gene was only a small part of its chromosome. On a statistical basis a (...) gene should escape disruption for many generations. This led George Williams and Richard Dawkins to a new definition of the gene, differing from conventional biochemical definitions in that there were no consistent genic boundaries. There had been no previous sightings of another revolutionary, albeit less verbally spectacular, comet that appeared in 1975—the homostability principle of Akiyoshi Wada. Each gene has a base composition “accent” that distinguishes it from its neighbors. We now see that recombination can be triggered by the shift in base composition at genic boundaries. Hence, the Williams-Dawkins definition approaches the conventional definitions. (shrink)

Despite the burgeoning interest in new and more complex accounts of the organism-environment dyad by biologists and philosophers, little attention has been paid in the resulting discussions to the history of these ideas and to their deployment in disciplines outside biology—especially in the social sciences. Even in biology and philosophy, there is a lack of detailed conceptual models of the organism-environment relationship. This volume is designed to fill these lacunae by providing the first multidisciplinary discussion of the topic of organism-environment (...) interaction. It brings together scholars from history, philosophy, psychology, anthropology, medicine, and biology to discuss the common focus of their work: entangled life, or the complex interaction of organisms and environments. (shrink)

The traditional practice of establishing morphological types and investigating morphological organization has found new support from evolutionary developmental biology (evo-devo), especially with respect to the notion of body plans. Despite recurring claims that typology is at odds with evolutionary thinking, evo-devo offers mechanistic explanations of the evolutionary origin, transformation, and evolvability of morphological organization. In parallel, philosophers have developed non-essentialist conceptions of natural kinds that permit kinds to exhibit variation and undergo change. This not only facilitates a construal of species (...) and higher taxa as natural kinds, but also broadens our perspective on the diversity of kinds found in biology. There are many different natural kinds relevant to the investigative and explanatory aims of evo-devo, including homologues and developmental modules. (shrink)

Responses are strengthened by consequences having to do with the survival of individuals and species. With respect to the provenance of behavior, we know more about ontogenic than phylogenic contingencies. The contingencies responsible for unlearned behavior acted long ago. This remoteness affects our scientific methods, both experimental and conceptual. Until we have identified he variables responsible for an event, we tend to invent causes. Explanatory entities such as “instincts,” “drives,” and “traits” still survive. Unable to show how organisms can behave (...) effectively under complex circumstances, we endow them with special abilities permitting them to do so.Behavior exhibited by most members of a species is often accepted as inherited if all members were not likely to have been exposed to relevant ontogenic contingencies. When contingencies are not obvious, it is perhaps unwise to call any behavior either inherited or acquired, as the examples of churring in honey guides and following in imprinted ducklings show. Nor can the relative importance of phylogenic and ontogenic contingencies be argued from instances in which unlearned or learned behavior intrudes or dominates. Intrusions occur in both directions.Behavior influenced by its consequences seems directed toward the future, but only past effects are relevant. The mere fact that behavior is adaptive does not indicate whether phylogenic or ontogenic processes have been responsible for it. Examples include the several possible provenances of imitation, aggression, and communication. The generality of such concepts limits their usefulness. A more specific analysis is needed if we are to deal effectively with the two kinds of contingencies and their products. (shrink)

The paper aims at proposing an extended notion of epigenesis acknowledging an actual causal import to the phenotypic dimension for the evolutionary diversification of life forms. “Introductory remarks” section offers introductory remarks on the issue of epigenesis contrasting it with ancient and modern preformationist views. In “Transmutation of forms: phenotypic variation, diversification, and complexification” section we propose to intend epigenesis as a process of phenotypic formation and diversification dependent on environmental influences, independent of changes in the genomic nucleotide sequence, and (...) occurring during the whole life span. Then, “Evolvability and phenotypic evolution” section focuses on phenotypic plasticity and offers an overview of basic properties that allows biological systems to be evolvable—i.e. to have the potentiality of producing phenotypic variation. Successively, the emphasis is put on environmentally-induced modifications in the regulation of gene expression giving rise to phenotypic variation and diversification. After some brief considerations on the debated issue of epigenetic inheritance, the issue of culture is considered. The key point is that, in the case of humans and of the evolutionary history of the genus Homo at least, the environment is also, importantly, the cultural environment. Thus, “Bio-cultural feedback” section argues that a bio-cultural feedback should be acknowledged in the “epigenic” processes leading to phenotypic diversification and innovation in Homo evolution. Finally, “Brain plasticity and cultural neural reuse” section introduces the notion of “cultural neural reuse”, which refers to phenotypic/neural modifications induced by specific features of the cultural environment that are effective in human cultural evolution without involving genetic changes. Therefore, cultural neural reuse may be regarded as a key instance of the bio-cultural feedback and ultimately of the extended notion of epigenesis proposed in this work. (shrink)

Parallels in anatomy between humans and domesticated mammals suggest that for the last 300,000 years, Homo sapiens has experienced more intense selection against the propensity for reactive aggression than any other species of Homo. Selection against reactive aggression, a process that can also be called self-domestication, would help explain various physiological, behavioral and cognitive features of humans, including the unique system of egalitarian male hierarchy in mobile hunter-gatherers. Here I review nine leading proposals that could potentially explain why self-domestication occurred (...) in H. sapiens, whether by selecting in favor of cooperation and tolerance or by selecting against aggressiveness. To account for the domestication syndrome, proposals must explain what led to a decline in fitness of highly aggressive males, and why the explanatory factor applies only to H. sapiens rather than to other species of Homo. The proposed explanations invoke genetic group selection; group-structured culture selection (also known as cultural group selection); social selection by female mate choice; social selection by male partner choice; increased self-control; cooperative breeding; high population density; use of lethal weapons; and language-based conspiracy. Most proposals face difficulties in accounting for the origins and/or maintenance of self-domestication. I conclude that the evolution of language-based conspiracy, which is a form of collective intentionality, was the key factor initiating and maintaining self-domestication in H. sapiens, because it is the most convincing mechanism for explaining the selective pressure against individually powerful fighters. Sophisticated language enabled males of low fighting prowess to coordinate in executing physically aggressive and domineering alpha males. This system is known today as a leveling mechanism in small-scale societies. Group-structured culture selection possibly accelerated the process. (shrink)

This book consists of a dialogue between two interlocutors, Pablo and a student, who discuss a great range of issues in social philosophy and political theory, and in particular, the emergence, working properties and economic effects of institutions. It uses the dialogical form to make philosophy more accessible, but also to show how ideas develop through intellectual interaction. The fact that one of the interlocutors is the "student" in a place in the real world makes the dialogue quasi-fictive in character (...) and enables the active engagement of the reader. After all, we are all philosophers and we develop our own philosophy by exchanging views and arguments. The dialogue form is and should remain the principal form of philosophizing, since ideas, like butterflies, do not merely exist – they develop. This is certainly the case in actual philosophical interaction, and it can be the case in written philosophical exposition. Although the dialogue does not presuppose prior acquaintance with the respective philosophical and social scientific literature under discussion in this book, it makes arguments more accessible, and conveys the feeling that there are no definite solutions to philosophical problems. (shrink)

Contingency-theorists have gestured to a series of phenomena such as random mutations or rare Armageddon-like events as that which accounts for evolutionary contingency. These phenomena constitute a class, which may be aptly called the ‘sources of contingency’. In this paper, I offer a probabilistic conception of what it is to be a source of contingency and then examine two major candidates: chance variation and genetic drift, both of which have historically been taken to be ‘chancy’ in a number of different (...) senses. However,contrathe gesturing of contingency-theorists, chance variation and genetic drift are not always strong sources of contingency, as they can be non-chancy in at least one sense that opposes evolutionary contingency. The probabilistic conception offered herein allows for sources of contingency to appropriately vary in strength. To this end, I import Shannon’sinformation entropyas a statistical measure for systematically assessing the strength of a source of contingency, which is part and parcel of identifying sources of contingency. In brief, the higher the entropy, the greater the strength. This is also empirically significant because molecular, mutational, and replicative studies often contain sufficient frequency or probability data to allow for entropies to be calculated. In this way, contingency-theorists can evaluate the strength of a source of contingency in real-world cases. Moreover, the probabilistic conception also makes conceptual room for the converse of sources of contingency: ‘sources of directionality’, which ought to be recognised, as they can interact with genuine sources of contingency in undermining evolutionary contingency. (shrink)

Darwin's ideas on variation, heredity, and development differ significantly from twentieth-century views. First, Darwin held that environmental changes, acting either on the reproductive organs or the body, were necessary to generate variation. Second, heredity was a developmental, not a transmissional, process; variation was a change in the developmental process of change. An analysis of Darwin's elaboration and modification of these two positions from his early notebooks (1836-1844) to the last edition of the /Variation of Animals and Plants Under Domestication/ (1875) (...) complements previous Darwin scholarship on these issues. Included in this analysis is a description of the way Darwin employed the distinction between transmission and development, as well as the conceptual relationship he saw between heredity and variation. This paper is part of a larger project comparing commitments regarding variation during the latter half of the nineteenth century. (shrink)

Abstract Charles Darwin, in his discussions with Asa Gray and in his published works, doubted whether God could so arrange it that exactly the desired contingent events would occur to cause particular outcomes by natural selection. In this paper, I argue that even a limited or neo-Leibnizian deity could have chosen a world that satisfied some arbitrary set of goals or functions in its outcomes and thus answer Darwin's conundrum. In more general terms, this supports the consistency of natural selection (...) with providentialism, and makes “theistic evolutionism” a coherent position to hold. (shrink)

Darwin proposed that evolutionary novelties are environmentally induced in organisms “constitutionally” sensitive to environmental change, with selection effective owing to the inheritance of constitutional responses. A molecular theory of inheritance, pangenesis , explained the cross‐generational transmission of environmentally induced traits, as required for evolution by natural selection. The twentieth‐century evolutionary synthesis featured mutation as the source of novelty, neglecting the role of environmental induction. But current knowledge of environmentally sensitive gene expression, combined with the idea of genetic accommodation of mutationally (...) and environmentally induced change, supports a revival of Darwin's original theory that is consistent with modern molecular and population genetics. †To contact the author, please write to: Smithsonian Tropical Research Institute, c/o Escuela de Biología, Universidad de Costa Rica, Costa Rica; e‐mail: [email protected]. (shrink)

Weismann's ideas on species transmutation were first expressed in his famous debate with Moritz Wagner on the mechanism of speciation. Wagner suggested that the isolation of a colony from its original source is a preliminary and necessary factor for speciation. Weismann accepted a secondary, facilitating role for isolation, but argued that natural and sexual selection are the primary driving forces of species transmutation, and are always necessary and often sufficient causes for its occurrence. The debate with Wagner, which occurred between (...) 1868 and 1872 within the framework of Darwin's discussions of geographical distribution, was Weismann's first public battle over the mechanism of evolution. This paper, which offers the first comprehensive analysis of this debate, extends previous analyses and throws light on the underlying beliefs and motivations of these early evolutionists, focusing mainly on Weismann's views and showing his commitment to what he later called "the all sufficiency of Natural Selection." It led to the crystallization of his ideas on the central and essential role of selection, both natural and sexual, in all processes of evolution, and, already at this early stage in his theoretical thinking, was coupled with sophisticated and nuanced approach to biological organization. The paper also discusses Ernst Mayr's analysis of the debate and highlights aspects of Weismann's views that were overlooked by Mayr and were peripheral to the discussions of other historians of biology. (shrink)

Melanin, and other pigments have recently been shown to preserve over geologic time scales, and are found in several different organisms. This opens up the possibility of inferring colours and colour patterns ranging from invertebrates to feathered dinosaurs and mammals. An emerging discipline is palaeo colour: colour plays an important role in display and camouflage as well as in integumental strengthening and protection, which makes possible the hitherto difficult task of doing inferences about past ecologies, behaviours, and organismal appearance. Several (...) studies and techniques have been presented in the last couple of years that have described ways to characterize pigment patterns. Here, I will review the available methods and the likely applications to understand past ecologies. A golden age of colourized dinosaurs and other animals is now dawning upon us, which may elucidate the nature of ancient predator prey interactions and display structures.Also watch the Video Abstract. (shrink)

Butler’s idea of evolution was developed over the publication of four books, several articles and essays between 1863 and 1890. These publications, although never achieving the success expected by Butler, proposed a psychological elaboration of evolution, called ‘unconscious memory’. This was strongly in contrast with the materialistic approach suggested by Darwin’s natural selection. Starting with a historical introduction, this paper aspires to ascertain the logic, meaning and significance of Butler’s idea of ‘unconscious memory’ in the post-Darwinian physiological and psychological Pan-European (...) discussion. Particular attention is devoted to demonstrating that Butler was not only a populariser of science but also an active protagonist in the late Victorian psychological debate. (shrink)