Chimpocentrism and reconstructions of human evolution (a timely reminder)

Chimpanzees, but very few other animals, figure prominently in (recent) attempts to reconstruct the evolution of uniquely human traits. In particular, the chimpanzee is used (i) to identify traits unique to humans, and thus in need of reconstruction; (ii) to initialize the reconstruction, by taking its state to reflect the state of the last common ancestor of humans and chimpanzees; (iii) as a baseline against which to test evolutionary hypotheses. Here I point out the flaws in this three-step procedure, and show how they can be overcome by taking advantage of much broader phylogenetic comparisons. More specifically, I explain how such comparisons yield more reliable estimations of ancestral states and how they help to resolve problems of underdetermination inherent to chimpocentric accounts. To illustrate my points, I use a recent chimpocentric argument by Kitcher.