Faces of human evolution

The Smithsonian Magazine has a very nice online feature that presents seven reconstructions of various extinct hominins that John Gurche crafted for the new National Museum of Natural History’s David H. Koch Hall of Human Origins that opens in two weeks.

The piece describes how he "dissected the heads of modern humans and apes, mapping patterns of soft tissue and bone. He used this information to fill out the features of the fossils. Each sculpture starts with the cast of a fossilized skull; Gurche then adds layers of clay muscle, fat and skin."

I especially liked the quote about how he "even molds the hominids’ eyes out of acrylic plastic, eschewing pre-fabricated versions. "If you want the eyes to be the window to the soul,” Gurche says, “you have to make them with some depth."

To give you an idea of the quality of the reconstructions, here's one of his reconstructions, that of a Neanderthal male (what else!).


From http://www.smithsonianmag.com/science-nature/A-Closer-Look-at-
Evolutionary-Faces.html?c=y&page=6 ; copyright John Gurche.

These are extremely well done reconstructions, and quite accurate, IMO, and it helps that Gurche gives a bit of background on each of the hominins he reconstructed - gives a nice idea of how he approached this task. I should add that, really, the power of these reconstructions to help make human revolution more accessible to wider audiences can't be overemphasized. I once gave a presentation about what a paleoanthropologist does to a class of kindergartners, and they went absolutely nuts for this picture, mainly I think because they could more easily relate their own lives to that of a small hominin child (and since this was in Montreal, I didn't have to blur out the "boy parts")...

From http://yalepress.yale.edu/yupbooks/images/interior13/9780300100471/africanus_taung_baby_72dpi.jpg; Copyright Yale University Press.

Of course, I didn't tell them just how accurate this picture is, what with the raptor in the upper left and the fact that there is good evidence the Taung Child bears traces that indicate he was likely killed by a bird of prey (Berger 2006)! That last image is drawn from The Last Human: A Guide to Twenty-Two Species of Extinct Humans, put out by Yale UP and lavishly illustrated with high-quality reconstructions of extinct hominins. I drew on the illustrations of the book extensively when I taught Human Evolution at McGill a few years ago... lost that book in the recent move to Denver, though. Still dearly wish I had it!

References

Berger, Lee R. 2006. Predatory bird damage to the Taung type-skull of Australopithecus africanus Dart 1925. American Journal of Physical Anthropology 131:166-168.

Very low human population size in the Lower Pleistocene

From the NY Times, reporting on a study estimating the "effective" population size of hominins ca. 1.2 million years ago based on three versions of the human genome:

They put the number at 18,500 people, but this refers only to breeding individuals, the “effective” population. The actual population would have been about three times as large, or 55,500.

Comparable estimates for other primates then are 21,000 for chimpanzees and 25,000 for gorillas. In biological terms, it seems, humans were not a very successful species, and the strategy of investing in larger brains than those of their fellow apes had not yet produced any big payoff. Human population numbers did not reach high levels until after the advent of agriculture.

That notion that humans were not very successful is an interesting one, especially considering how far-ranging they were by that point. By that tims, hominins were found all over Africa, all the way to Indonesia, along the northern Mediterranean rim and even as far septentrionally as the Republic of Georgia (i.e., the Dmanisi specimens). I'll be curious to see how the study accounts for this, unless this is it:

But that estimate would apply to the worldwide population only if there were inbreeding between the humans on the different continents. If not, and if modern humans are descended from just one of these populations, like Homo ergaster in Africa, then the estimate would apply only to that.

Richard G. Klein, a paleoanthropologist at Stanford, said it was hard to believe the population from which modern humans are descended was as small as 18,500 “unless they were geographically restricted to Africa or a small part of it.”

Can't wait to read the paper.

Welcome ANTH 203C: Human Evolution!

I've started teaching the summer installment of our introductory "Human Evolution" course today, and might thus be shifting the focus of AVRPI some for the coming weeks to deal more with general issues in human evolution and evolutionary theory. If you've come here from the 203C WebCT, welcome and feel free to explore a bit!

Hot off the presses!

If you're genuinely interested in human evolution, you should probably read a forthcoming paper in PNAS entitled "Recent acceleration of human adaptive evolution" by John Hawks and colleagues.

I'm reading through it as I type, but until I post some comments on it, feel free to check out what Greg Laden and Gene Expression have to say about it.