Friday, December 4, 2009
Four Stone Hearth #81
Welcome to this addition of Four Stone Hearth! Sorry for getting it up a couple days late. This weeks edition has several perspectives on human evolution. Over at anthropology.net, Tim Jones follows up Turkey Day with a discussion on the archaeological evidence for bird consumption in the Middle Pleistocene. While bird consumption may have been overlooked due to a focus on larger prey items, catching prey that can fly away indicates sophisticated hunting techniques. Over at Ad Hominen, Ciarán Brewster argues that Chins do Not a Human Make; rather, the presence of a slight chin in archaic Homo, as well as the lack of a defined chin in some 'modern' Homo indicates gene flow between archaic and modern humans. So basically, the simple rule that I gave my students at the beginning of this week, "If it has a chin, it's a modern human," was apparently inaccurate.... Ooops.
Ciarán also pointed out a couple other posts to check out. Over at Gene Expression, Razib Khan discusses his thoughts on The Future of Human Evolution. Khan takes issues with Ian Tattersall's statements in National Geographic that large population size and extensive mobility makes further evolutionary change of our own species unlikely. Khan argues that, in a large population, even though fixation due to genetic drift is unlikely, more mutations arise, and selection can act more effectively. Furthermore, he argues that the mixing of different populations will not reduce variation; rather, it will result in the emergence of new genotypic combinations. At NeuroLogica, Steven Novella discusses the latest Update from Hobbiton. Steven addresses the limitations of the current evidence, the controversy over interpretations, and recent evidence, concluding that the small brain size of H. floresiensis, "suggests that H. floresiensis specifically evolved a small brain, while retaining a rather advanced tool-making ability. This has led some to speculate that H. floresiensis had a more efficient brain design – packing more cerebral power into a smaller space."
Don't drills have beautiful rear ends? Since this week's submissions have focused on paleoanthropology and human evolution, I'm adding in a few interesting primatological posts. Beast Ape discusses primate coloration in Badge of Status in Drills. While male coloration is often though to be a result of sexual selection, particularly as a result of female choice, a recent study has found that while male coloration in drills is a badge of social status, it does not relate to female preference within a given a given rank. Over at Prancing Papio, Raymond Ho discusses recent evidence for Grandmothering in Japanese Macaques. Although the evidence is limited and anecdotal, this is one of the first published accounts in support of the Grandmother Hypothesis from nonhuman primates. I think this is important, because I suspect there's been more observations of grandmothering in primates (I'm pretty sure I've heard of it happening in rhesus macaques, and wouldn't be surprised if there were accounts from other species as well), but anecdotal evidence is likely to go unreported. Hopefully this paper will spur some further investigation of this behavior. Finally, for those who haven't read my second installment on tool use and cognition, I highly suggest you read Can Water be Used as a Tool?
Thanks for reading this edition of Four Stone Hearth! The next edition will be hosted by Anthropology in Practice. If you're reading this, I encourage you to submit for future editions. The submissions with this week were predominantly biological, with a focus on human evolution; furthermore, they were all submitted by male bloggers! I'd love to see some more diversity in future editions!