The concept of an evolved adaptation.
A Darwinian adaptation is an organism's feature that was functionally designed by the process of evolution by selection acting in nature in the past. Functional design rules out explanations of drift, incidental effect, phylogenetic legacy and mutation. Elucidation of the functional design of an adaptation entails an implicit reconstruction of the selection that made the adaptation. Darwinian adaptations and other individual traits may be currently adaptive, maladaptive or neutral. One relatively recent meaning of adaptation is inconsistent with the Darwinian conception of adaptation. The inconsistent meaning characterizes much research on humans and non-human species in behavioural ecology. Its focus is on equating Darwinian adaptation with current adaptiveness. Current adaptiveness is not an actual scientific prediction of a hypothesis about Darwinian adaptation. Some aspects of the discussion in the evolutionary literature surrounding the current adaptiveness view of adaptation are evaluated. Contrary to claims by some who advocate current adaptiveness, the environment of evolutionary adaptedness of humans and other organisms is scientifically knowable through discovery of the functional design of Darwinian adaptations.
Thornhill
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Department of Biology, University of New Mexico, Albuquerque 87131, USA.
D000223:Adaptation, Psychological; D005075:Biological Evolution; D006801:Humans