The theoretical heuristic of assuming distinct alleles (or genotypes) for alternative phenotypes is the foundation of the paradigm of evolutionary explanation we call the Modern Synthesis. In modeling the evolution of sociality, the heuristic has been to set altruism and selfishness as alternative phenotypes under distinct genotypes, which has been dubbed the “phenotypic gambit.” The prevalence of the altruistic genotype that is of lower evolutionary fitness relative to the alternative genotype for non-altruistic behavior in populations is the basis of the (...) “paradox of altruism.” I show in this article that the assumption of contrasting genotypes for altruism and selfishness in our “phenotypic gambit” is inconsistent with the empirical data when viewed in the light of today’s post-Mendelian understanding of gene expression. I demonstrate that however nuanced and sophisticated the models may have become today, they are still rooted in that fundamentally problematic assumption. I then offer a genetic conception of altruism that best fits the field data. (shrink)

The adequacy of currently popular accounts of the genetic basis for psychological altruism, including inclusive fitness, reciprocal altruism, sociality, and group selection, is questioned. Problems exist both with the evidence cited as supporting these accounts and with the relevance of the accounts to what is being explained. Based on the empathy-altruism hypothesis, a more plausible account is proposed: generalized parental nurturance. It is suggested that four evolutionary developments combined to provide a genetic basis for psychological altruism. First is the evolution (...) in mammals of parental nurturance. Second is the evolution in humans of the ability to see others as sentient, intentional agents and, thereby, to recognize other's needs, even subtle ones. Third is the evolution in humans of tender, empathic emotions as an important component of parental nurturance. Fourth is the evolution in humans of cognitive capacities that make it possible to generalize tender, empathic feelings and, thereby, altruism beyond offspring. (shrink)

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Chagnon’s analysis of a well-known axe fight in the Yanomamö village of Mishimishiböwei-teri (Chagnon and Bugos 1979) is among the earliest empirical tests of kin selection theory for explaining cooperation in humans. Kin selection theory describes how cooperation can be organized around genetic kinship and is a fundamental tool for understanding cooperation within family groups. Previous analysis on groups of cooperative Lamaleran whale hunters suggests that the role of genetic kinship as a principle for organizing cooperative human groups could be (...) less important in certain cases than previously thought (Alvard Human Nature 14:129–163, 2003b). Evidence that supports a strong role for genetic kinship—groups are found to be more related than expected by chance—may be spurious because of the correlation between social structure and genetic kinship. Reanalysis of Chagnon’s data using matrix regression techniques, however, confirms that genetic kinship was the primary organizing principle in the axe fight; affinal relations were also important, whereas lineage identity explained nothing. (shrink)

Traditional model systems such as fly, mouse, and chick have formed the foundation of the EvoDevo research program. These animal systems have provided a wealth of information on the patterns and mechanisms of developmental change over large phylogenetic scales. However, the almost exclusive focus on individual embryos as model organisms has also limited the field’s ability to address the central roles that natural selection and life history adaptation play in the evolution of developmental systems. Likewise, focus on this small set (...) of “unitary” model organisms may also constrain the explanatory reach and theoretical robustness of EvoDevo if we consider that many core developmental processes like homeostatic regulation, ontogenetic differentiation, and norms of reaction are also manifest at other levels of biological organization, such as colonial organisms. The study of social insect systems can help bridge these considerable gaps in EvoDevo’s current approach. Because social insect colonies span the fine line between simple associations of “unitary” organisms and full-fledged “superorganisms,” these systems help elucidate what kinds of processes fundamentally characterize developmental systems and their evolution. What is more, the traits of social insect colonies show high degrees of population-level variability that can be linked directly to selective factors in the environment, making them ideal systems in which to more fully integrate EcoEvoDevo approaches. (shrink)

Edward O. Wilson’s recent decision to abandon kin selection theory has sent shockwaves throughout the biological sciences. Over the past two years, more than a hundred biologists have signed letters protesting his reversal. Making sense of Wilson’s decision and the controversy it has spawned requires familiarity with the historical record. This entails not only examining the conditions under which kin selection theory first emerged, but also the organicist tradition against which it rebelled. In similar fashion, one must not only examine (...) Wilson’s long career, but also those thinkers who influenced him most, especially his intellectual grandfather, William Morton Wheeler (1865–1937). Wilson belongs to a long line of organicists, biologists whose research highlighted integration and coordination, many of whom struggled over the exact same biological riddles that have long defined Wilson’s career. Drawing inspiration (and sometimes ideas) from these intellectual forebears, Wilson is confident that he has finally identified the origin of the social impulse. (shrink)