Behavioral Relics and Animal-Environment Mutualism: Commentary on Coss (1991)

Abstract

Coss (1991a) found that squirrels from populations that differed in their historical exposure to snakes reacted in a manner similar to that of squirrels sympatric with snakes when exposed to one; lab-reared pups also showed some typical reactions to a snake. Coss concluded that the squirrels possessed a genetic relic of the pattern of behavior typical of the common progenitor at a time when snakes exerted selection pressure on squirrel evolution. It is argued here that this concept of behavioral relics is suspect and should be employed with caution. The concept is difficult to apply rigorously, and the philosophy of the concept is diametrically opposed to the animal-environment mutualism espoused by ecological psycholo- gists. Three more parsimonious explanations for the phenomena reported in Coss (199 1 a) are suggested.