EVOLUTIONARY PERSISTENCE OF GROUND-SQUIRREL ANTISNAKE BEHAVIOR - REFLECTIONS

The evolutionary persistence construct considers the possibility that animals retain perceptual biases and behavioral relics from former his toric periods of natural selection. As critiqued by Burton (this issue ), this construct is suspect because it assumes that perceptual biases can be carried by the animal before it reaches the environment, a vie w contrary to those who consider behavior to be organism-environment t ransactions. Burton further argues that the laboratory study result sh owing that California ground squirrels from habitats where their snake predators are virtually absent behaved like squirrels from a snake-ab undant habitat could be an artifact of laboratory conditions. A more p arsimonious explanation than evolutionary persistence is that snakes a re perceived as generalized anxiety-provoking stimuli, not as specific predators. In response to this critique, evidence is presented that g round squirrel antisnake behavior is indeed functionally specialized f or dealing with snakes. Additional study of squirrel populations provi des further evidence that antisnake behavior is generally intact in gr ound squirrel populations experiencing prolonged relaxed selection for many thousands of years. The implications of the evolutionary persist ence construct for the theoretical structure of animal-environment mut ualism, ideas of direct perception, and the role of memory and cogniti on in different time scales are discussed.