A new paper in Evolutionary Anthropology reviews the causes of the global expansion of homo sapiens and argues that it was our propensities for cooperation and social learning that made this ecological dominance possible. The paper initially takes a distinctly macroecological perspective on the evolution of human culture, by commenting on some general facts reflecting the evolutionary success of humans.
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 dominance, and success of our species in colonizing every terrestrial habitat have no parallel.2 Moreover, Homo sapiens accounts for about eight times as much biomass as do all other terrestrial wild vertebrates combined,3 an amount equivalent to the biomass of all 14,000+ species of ants,4 the most successful terrestrial invertebrates. Human societies are complex, with more specialized economic niches in the United States than the total number of mammalian species on the planet.5 While some might suggest that only post-industrial humans achieved stunning biological success, data suggest that humans living as hunter-gatherers would have attained a world population of more than 70 million individuals6 and a total biomass greater than that of any other large vertebrate on the planet if agriculture had not been repeatedly invented as they spread. |
"we outline a series of preadaptations that may help explain why later Homo evolved unique traits that chimpanzee, elephant, and porpoise lineages did not. Other apes have large brains, regularly engage in social learning, and exhibit theory of mind. Moreover, those ape species also passed through the Pleistocene without evolving the combination of characters that make humans biological outliers. We must, therefore consider important preadaptations in the genus Homo that led to human uniqueness.”
This is an excellent review paper that I'm sure will get a lot of attention. Its interesting to see human behavioral ecologists paying progressively more attention to cultural evolution and group level dynamics as major driving forces in the expansion of homo sapiens. I might add that this topic general, that is asking the big 'why questions' about what factors made humans such an expansive force as Pleistocene hunter-gatherers, receives strikingly little attention from evolutionary ecologists. | |
