11 Rethinking Paleoanthropology : A World Queerer Than We Supposed

The universe is not only queerer than we suppose, it is queerer than we can suppose. A dvances in paleoclimatology and paleoecology are producing an ever more detailed picture of the environments in which our species evolved, helping us to understand the processes by which our large brain and its productions—toolmaking, complex social institutions, language, art, religion—emerged. Our large brain relative to body mass and the extreme elaboration of our cultures differentiate us from our nearest relatives. We achieved our present anatomy and behavioral repertoire very recently. Fossil material attributable to our species goes back perhaps 200,000 years ago (200 kya), by which time the brain of our species and of Neandertals had reached nearly modern proportions. Artifacts that strike us as representing fully modern behavior are rare early in the record of our species, and only become abundant after 50 kya, and then mainly in western Eurasia (Marean et al. 2007, Klein 2009). Our ecological dominance began with the evolution of agriculture starting about 10,000 years ago (Vitousek et al. 1997). Explaining the late coming of human brains is a major evolutionary puzzle as most important animal adaptations are old. Eyes, internal skeletons , adaptations for terrestrial life and for flight all date back hundreds of millions of years. Many lineages of fully terrestrial animals have re-adapted