Mary Lee Jensvold & Lori K. Sheeran
Biological anthropologists use the comparative perspective in their efforts to reconstruct human evolutionary history. As our closest living relatives, primates are often used to frame comparisons and to test hypotheses about various human features. A feature (behavioral, genetic, or anatomical) that appears in all primate species is at least initially assumed to also characterize the last common ancestor of those species; features present in only one form presumably evolved at some point after it diverged, and hypotheses explaining the features are developed in the context of unique aspects of the organism's ecology and anatomy. The large-bodied apes (orangutans, gorillas, chimpanzees, and bonobos) are most closely related to humans, so those species, particularly chimpanzees, are the preferred ones to compare to fossil and living humans. However, comparisons between humans and other more distantly related species are also informative and serve to demonstrate instances of evolutionary convergences (similar selective pressures lead to ...