Monday, November 9, 2009

New Paper on Human Uniqueness

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.

The emergence of human uniqueness: Characters underlying behavioral modernity
Kim Hill, Michael Barton, A. Magdalena Hurtado
email: Kim Hill ( Michael Barton ( A. Magdalena Hurtado (

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.

Thursday, January 29, 2009

First Americans Paper in PNAS

PNAS published a review paper on the peopling of the Americas authored by Tom Dillehay.
I have to say it strikes me as kind of an odd paper to appear in a journal like PNAS. Its title is 'Probing Deeper into First American Studies' and yet it really doesn't report anything new and as a review paper goes the synthesis of existing data is just sort of... so so. Also interesting is that even though it explicitly addresses different ideas about how the New World was colonized, it does not cite a paper written on this very topic that was published in this very journal within the last year. Is that odd? I think so. Especially since its a novel and interdisciplinary approach to understanding migrations and that is exactly what Dillehay says we need more of...
Here's a quote from the paper:

"Places of origin, dates of entry, routes of dispersion, and types of early cultural lifestyles lie at the heart of the debate over the initial peopling of the Americas. Fresh thinking about these and other issues has occurred because of the recent demise of the Clovis-first paradigm to explain the initial peopling of the Americas (2, 6, 7, 8) and because of new and more flexible interdisciplinary research directions."

I have to admit I'm also a bit tired of the Monte Verde crowd claiming that the 'Clovis-first paradigm' has been defeated because of sites like, well... Monte Verde, which is much more problematic than we're aloud to acknowledge. If you do question it, prepare to be berated by Dillehay and his friends. (Also, 'paradigm' ? really? clearly Clovis-first is nothing like an actual paradigm as defined by Thomas Kuhn. Just a pet peeve...)

Just the same, this will continue to be a hot topic in archaeology and hopefully the issues raised in this short reivew will be resolved with new data and research in the future.

Sunday, January 25, 2009

Water bears: just because everyone should know about these

This doesn't come from an obscure source or anything like. Just NPR's Science Friday, but here's a very cool video they posted on their website. Enjoy it.
Locations of visitors to this page