Wednesday, March 02, 2011

The Combe Capelle burial is Holocene in age

So says this Past Horizons report. This is fairly important in that it joins a bunch of other modern Homo sapiens remain long thought to have been associated with the Aurignacian to recently have been directly dated and shown to be much more recent (Churchill and Smith 2000). One recent and well publicized case was that of the Vogelherd remains, which were redated to between 3.9-5kya as opposed to the 30+kya it was originally thought to date to (Conard et al. 2004).

In the case of Combe Capelle, the redating of the skeleton to ca. 9575BP (the report doesn't give the exact age range) is especially significant for two reasons. For one thing, it's one more blow to the idea that modern humans were in Europe from the very beginning of the Upper Paleolithic. For another thing, and perhaps most importantly, it conclusively dissociates this set of modern human bones from the Chatelperronian artifacts with which it was found. As I've argued before, who made the Chatelperronian is now hotly debated, and this new piece of the puzzle just makes the question even more intriguing.

Edit Also, check out this photo (included in the Past Horizons report) of Otto Hauser, who discovered the burial, posing with the remains themselves... you just don't see photos like that in paleoanthropology anymore!


Churchill SE, & Smith FH (2000). Makers of the early Aurignacian of Europe. American journal of physical anthropology, Suppl 31, 61-115 PMID: 11123838

Conard, N., Grootes, P., & Smith, F. (2004). Unexpectedly recent dates for human remains from Vogelherd Nature, 430 (6996), 198-201 DOI: 10.1038/nature02690

Obsidian blades as surgical tools

In my recent post on #hipsterscience, the quote that struck closest to home was the one about the obsidian blade. See, most of my analytical work ResearchBlogging.orgThis post was chosen as an Editor's Selection for ResearchBlogging.orghas been focused on stone tools (aka lithics) and how they were manufactured, used and managed by people in the past. Whenever it was available, obsidian seems to have been one of the preferred materials to make sharp flakes of, mainly because it is incomparably sharp among lithic raw materials!

Just how sharp is obsidian? Extremely damn frikkin' sharp! I often regale students about the first time I knapped stone myself, a sad, sordid story that ends with a fountain of blood gushing from the tip of my index finger (not that I would ever exaggerate for dramatic effect or anything). Well, that bloody geyser was unleashed by a flake of coarse flint - and obsidian is much, much sharper than that. When I've given knapping demos using obsidian and inadvertently nicked myself with little obsidian flakes, they're so sharp that I usually didn't notice I was bleeding until I smeared blood all over myself - this made knapping look pretty bad-ass to at least one group of sixth graders I once gave a demo to.

But don't take my word for it! Lithic specialists often refer to the story of Don Crabtree (one of the people directly responsible for the rebirth of knapping in the 60's and 70's) insisting that he be operated on by surgeons using scalpels tipped with obsidian blades he had expressly knapped for the purpose. Buck (1982) reports some observations on this episode, as well as on experiments comparing the obsidian to steel scalpel blades, concluding that, at 30 angstrom (i.e., 3 nanometers; that's three billionth of a meter) obsidian is much sharper than even the sharpest steel blade, the cuts it produces heal just as well if not better than those made with a steel surgical blade, and contrary to some concerns, it doesn't chip or leave residues when employed to operate on soft tissue. Specifically, he observes that

In most fields of surgery, of course, a modicum
of sharpness suffices, and one feels comfortable
with the convenience of the modem disposable
steel blade. However, in many specialized areas,
scalpel blades and razor blades leave much to be
desired. Examples that come to mind are the
debridement of nerve ends for repair, microvascular
surgery, fine plastic work on thin skin (blepharoplasty,
for example) and ophthalmologic surgery.
Though one with faith in modem technology
cannot imagine that instruments equal to these
various tasks cannot be produced today, the fact
remains that no honed metal edge has matched
that of the glass blade to date. (Buck 1982: 269)

Since the results of that brief experimental study were published almost thirty years ago, however, there hasn't been much of a push for obsidian tipped surgical instruments. My guess as to why this might be the case, beyond inertia in surgical equipment trends, is that some of the practical aspects of making obsidian blades might have been underestimated by Buck, especially those concerning standardization in shape and thickness, along with the properties of various grades of obsidian.

Edit (03/03/2001, 10:45AM): Hey! This post was included in this week's ResearchBlogging 'Editor's Selection' for the social sciences! Sweet!


Buck BA (1982). Ancient technology in contemporary surgery. The Western journal of medicine, 136 (3), 265-9 PMID: 7046256

Tuesday, March 01, 2011

Anthropology meets #hipsterscience

I never really got the big deal about Twitter (nor do I really get how hashtags work, to be perfectly honest), but Drug Monkey has a blog post compiling #hipsterscience tweets, and they're pretty damn funny! A couple are paleo/anthropological in nature, so I figured I'd share them here:

drugmonkeyblog: You get a better shave with a blade you’ve freshly knapped from fair-trade, small producer obsidian @drisis #hipsterscience #hipsteranthro

cambrianexplode: Evolution? I like the early stuff but it’s all gotten so predictable now. #hipsterscience

And finally, this one made me burst out laughing and wipe off coffee from my screen:

dorsalstream: I only work with skinny genes. #hipsterscience