Although scientists are aware that humans share the same biological heritage as do all other organisms on the planet, the reliance of Homo sapiens on culture and cooperation has resulted in what can best be described as ‘‘a spectacular evolutionary anomaly.’’1:11 The extra-somatic adaptations, technological domi-nance, and success of our species in colonizing every terrestrial habitat have no parallel.2 Moreover, Homo sapiens accounts for about eight times as much bio-mass as do all other terrestrial wild vertebrates combined,3 an amount equiva-lent to the biomass of all 14,000þ species of ants,4 the most successful terres-trial invertebrates. Human societies are complex, with more specialized eco-nomic niches in the United States than the ...