The selected effects or ‘etiological’ theory of Proper function is a naturalistic and realist account of biological teleology. It is used to analyse normativity in philosophy of language, philosophy of mind, philosophy of medicine, and elsewhere. The theory has been developed with a simple and intuitive view of natural selection. Traits are selected because of their positive effects on the fitness of the organisms that have them. These ‘selected effects’ are the Proper functions of the traits. Proponents argue that this (...) analysis of biological teleology has the unique advantage that the selected effect function of a trait is also a causal explanation of the trait: the trait exists because it performs this function. We show, however, that selected effect functions as currently defined explain the existence of traits only under highly restrictive assumptions about evolutionary dynamics. In many common scenarios in which traits evolve by natural selection, selected effect functions do not explain those traits. This is because definitions of selected effect function extract from any evolutionary scenario only the information that would be explanatorily relevant in the simple evolutionary scenario implicit in those definitions. When applied to more complex scenarios, selected effect functions omit the key information that is explanatorily relevant in those scenarios. The assumptions required for selected effect functions to be explanatory are particularly unlikely to hold in the domain that its proponents care most about—the evolution of representation. A more adequate selected effects theory of Proper functions may be possible, but will require much greater attention to the structure of actual evolutionary explanations. (shrink)

Integrating the study of human diversity into the human evolutionary sciences requires substantial revision of traditional conceptions of a shared human nature. This process may be made more difficult by entrenched, 'folkbiological' modes of thought. Earlier work by the authors suggests that biologically naive subjects hold an implicit theory according to which some traits are expressions of an animal's inner nature while others are imposed by its environment. In this paper, we report further studies that extend and refine our account (...) of this aspect of folkbiology. We examine biologically naive subjects' judgments about whether traits of an animal are 'innate', 'in its DNA' or 'part of its nature'. Subjects do not understand these three descriptions to be equivalent. Both innate and in its DNA have the connotation that the trait is species-typical. This poses an obstacle to the assimilation of the biology of polymorphic and plastic traits by biologically naive audiences. Researchers themselves may not be immune to the continuing pull of folkbiological modes of thought. (shrink)

We assess the arguments for recognising functionally integrated multispecies consortia as genuine biological individuals, including cases of so-called ‘holobionts’. We provide two examples in which the same core biochemical processes that sustain life are distributed across a consortium of individuals of different species. Although the same chemistry features in both examples, proponents of the holobiont as unit of evolution would recognize one of the two cases as a multispecies individual whilst they would consider the other as a compelling case of (...) ecological dependence between separate individuals. Some widely used arguments in support of the ‘holobiont’ concept apply equally to both cases, suggesting that those arguments have misidentified what is at stake when seeking to identify a new level of biological individuality. One important aspect of biological individuality is evolutionary individuality. In line with other work on the evolution of individuality, we show that our cases can be distinguished by focusing on the fitness alignment between the partners of the consortia. We conclude that much of the evidence currently presented for the ubiquity and importance of multi-species individuals is simply not to the point, at least unless the issue of biological individuality is firmly divorced from the question of evolutionary individuality. (shrink)

In behavioral ecology some authors regard the innateness concept as irretrievably confused whilst others take it to refer to adaptations. In cognitive psychology, however, whether traits are 'innate' is regarded as a significant question and is often the subject of heated debate. Several philosophers have tried to define innateness with the intention of making sense of its use in cognitive psychology. In contrast, I argue that the concept is irretrievably confused. The vernacular innateness concept represents a key aspect of 'folkbiology', (...) namely, the explanatory strategy that psychologists and cognitive anthropologists have labeled 'folk essentialism'. Folk essentialism is inimical to Darwinism, and both Darwin and the founders of the modern synthesis struggled to overcome this way of thinking about living systems. Because the vernacular concept of innateness is part of folkbiology, attempts to define it more adequately are unlikely to succeed, making it preferable to introduce new, neutral terms for the various, related notions that are needed to understand cognitive development. (shrink)

Developmental systems theory (DST) is a general theoretical perspective on development, heredity and evolution. It is intended to facilitate the study of interactions between the many factors that influence development without reviving `dichotomous' debates over nature or nurture, gene or environment, biology or culture. Several recent papers have addressed the relationship between DST and the thriving new discipline of evolutionary developmental biology (EDB). The contributions to this literature by evolutionary developmental biologists contain three important misunderstandings of DST.

The 'developmental systems' perspective in biology is intended to replace the idea of a genetic program. This new perspective is strongly convergent with recent work in psychology on situated/embodied cognition and on the role of external 'scaffolding' in cognitive development. Cognitive processes, including those which can be explained in evolutionary terms, are not 'inherited' or produced in accordance with an inherited program. Instead, they are constructed in each generation through the interaction of a range of developmental resources. The attractors which (...) emerge during development and explain robust and/or widespread outcomes are themselves constructed during the process. At no stage is there an explanatory stopping point where some resources control or program the rest of the developmental cascade. 'Human nature' is a description of how things generally turn out, not an explanation of why they turn out that way. Finally, we suggest that what is distinctive about human development is its degree of reliance on external scaffolding. (shrink)

It’s an honour to have so many major contributors to the literature respond to our article and we thank them for their thoughtful responses. There are clear shared themes across these commentaries,...