ENVIRONMENTS OF NATURAL SELECTION

Understanding the evolution of great ape cognition depends on identifying past adaptive settings and the factors that influenced early ape cognitive responses. Reconstructing past environments is not sufficient for developing and testing evolutionary arguments. It is the sequence of selective environments in which ancestral apes lived that is essential to determining how great ape mental abilities evolved. This requires us to assess the ways in which environmental settings (i.e., specific habitat reconstructions), trends (e.g., cooling, drying), and variability (e.g., seasonality and long-term oscillation) affected the resources and survival regimes of ancestral great apes – and thus posed adaptive problems in the places where they lived and the time periods when they evolved. This chapter investigates the evolutionary adaptability of great apes in light of local, regional, and global paleoenvironments; the geographic patterns of ape evolution; and the cognitive, social, environmental, and dietary characteristics of living great apes.

PRIOR HYPOTHESES OF GREAT APE COGNITIVE EVOLUTION

Although attempts to define unique aspects of great ape cognition have generated much debate (e.g., Tomasello & Call 1997), great apes appear to have achieved levels of cognitive sophistication and flexibility unknown in other nonhuman primates.