New PaleoAnthropology papers

PaleoAnthropology,, the official publication of the Paleoanthropology Society, has a number of new reviews and papers out, as of yesterday (methinks). The papers are available for free in pdf format. Look for some thoughts on the piece entitled "Eco-Cultural Niche Modeling: New Tools for Reconstructing the Geography and Ecology of Past Human Populations " in the near future. Time has been kind of tight lately, but I'll be posting more very soon, so keep posted!

Update on Creswell Crags

There's a short online report detailing the results of recent excavations at the British rock art site of Creswell Crags. Given that the team was digging up the spoil heap of 19th Century excavations that took place at the site, it's perhaps not surprising they didn't find too much. What they did find, however, covers the range from the Middle Ages all the way to the Gravettian. The exact nature of all Pleistocene chronological attributions is unclear.

Not terribly informative as to exactly what was found, tool-wise, aside from a potential Pleistocene awl, though the report includes this tentalizing if vague excerpt:

"There was one possible find of Ice Age art, which researchers will be examining further, and the excavation will provide the archaeologists with enough information to plan a further major dig at the site next year."

The report does include a neat image showing the outline of some of the engraved stags identified in 2003 and 2004.

Study break of sorts

I'm in Genoa until mid-September, studying Paleolithic lithic collections from Riparo Bombrini with my colleague Fabio Negrino, but I have web access so I should keep posting relatively regularly.

While in Europe, I'll also take a week off to attend the quinquennal UISPP meetings in Lisbon, Portugal, where I'm presenting papers on aspects of my doctoral research. The full program of the 2006 meetings is now available online in pdf format on the conference website and, for anyone with an interest in prehistoric research in the broadest sense, it's sure to be a treasure trove of information, since the abstracts are included as well. Individual sessions, such as Setting the Record Straight: Toward a Systematic Chronological Understanding of the Middle to Upper Palaeolithic Boundary in Eurasia also have individual web pages, or more detailed information in pdf format. Should be a great conference, and Lisbon, well, is Lisbon!

Henri de Monfreid, archaeologist

Reading through a paper by David Pleurdeau "in press" in the African Archaeological Review, I stumbled upon a reference to the original discoverers of Porc-Epic Cave, a Middle Stone Age (MSA) site in Ethiopia. Almost everyone interested in the MSA of East Africa knows that P. Theillard de Chardin (1930) was one of them (see also Pleurdeau 2005); fewer know that Henri de Monfreid was the other. Fewer still probably know about Henri de Monfreid, a French expat (mainly) who lived an adventurous life on and along the coast of the Red Sea, trafficking in weapons and other things, and doing a number of things often not completely within the bounds of the law. As it happens, Monfreid was also a very talented and prolific writer who captured a number of his experiences in written form. The first Monfreid book I had the pleasure to read back in 1994 was La croisière du Hachich, translated into English under the title Hashish (a fantastic read!), and I've been hooked ever since, reading compulsively anything of his I've come across over the years. A good overview of Monfreid's life and artistic output (he was also a painter) is provided by P. Baraduc in his Henri de Monfreid: Flibustier de la Mer Rouge (1998).

He is, hands down, one of my favorite writers, and it was a small pleasure to learn that he had, on top of all else he did over his lifetime, done paleoanthropological and ethnological work.

References

Baraduc, P. 1998. Henri de Monfreid: Flibustier de la Mer Rouge. Collection "Grandes aventures." Arthaud, Paris.

Monfreid, H. de. 1933. La croisière du Hachich. Grasset, Paris.

Pleurdeau, D. 2005. Le Middle Stone Age de la grotte du Porc-Épic (Dire Dawa, Éthiopie) : gestion des matières premières et comportements techniques: Porc-Epic cave (Dire Dawa, Ethiopia). L'Anthropologie 107:15-48.

Pleurdeau, D. 2006. Huma technical behavior in the African Middle Stone Age: the lithic assemblage from Porc-Epic Cave (Dire Dawa, Ethiopia). African Archaeological Review 22: in press. (DOI: 10.1007/s10437-006-9000-7)

All Mellars, all the time

Paul Mellars is enjoying a rather prolific year, as far as publishing review papers in high-profile journals is concerned. The latest one can be found in Science and concerns the archaeological evidence from southern Asia between 50 and 30,000 BP. Unsurprisingly, Mellars argues that these artifacts provide indisputable evidence for the dispersal of (not to say the colonization of the Old World by) anatomically and behaviorally modern humans. Now, there's things I like about this papers, and things I dislike.

On the “like” side, Mellars present evidence from an area that is largely unknown (and therefore undiscussed) by most researchers concerning themselves with modern human origins research. This therefore exposes the rest of the discipline to data that offer the potential to confirm or contradict current ideas and models. This is done in his usual concise and engaging style, which is not something that is given to all paleoanthropologists to be able to do.

On the “dislike” side, Mellars once again (see Mellars 2006a) implicitly presents archaeology as simply an ancillary line of evidence to be at worst fitted to or at best compared to the conclusions reached by seemingly serious disciplines like evolutionary genetics and human paleontology (see discussion in Marks 2003). This, in my view, seriously demeans archaeology as an independent field of study which has a lot to offer. I think part of why Mellars perhaps unwittingly depicts archaeology in such a way has to do with his approach to archaeology. For him, archaeology is largely a culture-historical exercise, meaning that the goal of archaeology is to track the extant and duration of given “cultures.” From this perspective, artifacts are not so much objects that were used by prehistoric hominins to achieve given ends but signals of group identity. In this sense, a Dufour bladelet, say, becomes simply the Paleolithic equivalent of a coin of a given age and provenience in numismatics.

As I've said before, this is not inherently wrong, and some artifacts unquestionably have restricted temporal and geographical distributions. However, this perspective stands in stark contrast to the goals of anthropological archaeology and evolutionary ecology, which are to understand how people acted in the past and why. For anyone interested in evolutionary processes in the deep past, these are the questions that should matter. To simply plot the distribution of culture groups does nothing to explain the evolutionary storyline to which they belong, it merely sets the stage. It's like stating that a book comprises X number of chapters without explaining how the chapters are related and why one chapter comes to a close when and how it does. To me at least, this is very unsatisying.

Getting back to the paper itself, however, there are some more serious issues with some of Mellars' assertions. As concerns the genetic evidence for a single population diffusing from Africa, he brushes aside known problems with studies of mitochondrial and Y-chromosome DNA that potentially support the existence of two separate populations despite citing fully eight such critiques, which is no small number considering that he cites only seven studies in support of his argument. This is not necessarily critical, since studies are liable to criticisms even if they are not thoroughly flawed, but these numbers do give pause.

As far as the archaeology is concerned, Mellars makes his case for a direct link between Africa and southern Asia by presenting evidence that a handful of sites dated to between 30-34 kya (calibrated, which means roughly 27-31 kya uncal, which corresponds to the beginning of the Gravettian and not the Aurignacian in Europe!!) yielded “crescentic” forms and ostrich eggshell beads similar to a handful of African Howiesons' Poort (and Howiesons' Poort-like) assemblages dating to at most 65 kya. In passing, Mellars once again repeats his assertion that such lithics may have been parts of arrows, something which I have shown to be unsupported by any hard evidence in two previous posts (the first, the second). As concerns the lithics, the argument for analogy is unconvincing on two levels. On a purely empirical level, a casual inspection of the drawings of them presented by Mellars suggests that the majority of the southern Asian artifacts were made on flake blanks, which is a very different way to manufacture crescentic forms than the backing of blade segments that characterizes the African material. Further, Mellars presents no data whatsoever about the rest of the lithic assemblages to which these crescents belong. In the Howiesons' Poort of Klasies River Mouth, Wurz (2002) has shown “crescents” are present in the hundreds! They thus represent a central part of the assemblage. Unless the lithic assemblages from southern Asia can be shown to display a similar dependence on crescent technology, any argument about whether they represent the same “culture” or even more simply the same “way of doing things” is unsupported. Otherwise, one would have to say that the Uluzzian of southern Italy, which Mellars himself has repeatedly and unwaveringly assigned to Neanderthals (e.g., Mellars 1996, 2004, 2005), would have to be taken as proof positive of modern human expansion in that part of the world as well.

On a conceptual level, it is also very interesting to take a look at how Mellars attempts to present the case for a cultural connection between Africa and southern Asia. Rather than presenting any contextual data about the assemblages which he mentions, he limits himself to presenting composite pictures of “representative” artifacts from, on one side, southern Asia and, on the other, Africa. It doesn't matter that in both instances the assemblages invoked are separated by hundreds if not thousands of years and kilometers. A telling analogous argument is that put forward by Bradley and Stanford (2004) which alleges that the Clovis Paleoindian culture of North America derives from the influence of western European Solutrean migrants who would have crossed the Atlantic to settle the Americas. This argument has been debunked in press by a number of paleoanthropologists (e.g., Sellet 1998, Straus 2000, Clark 2004) and does not appear – to the best of my knowledge – to enjoy widespread credence among the archaeological community as a whole. Interestingly in the context of this discussion of Mellars' latest paper, however, in their latest paper Bradley and Stanford's discussion of actual artifacts is illustrated only by a set of three figures (2004:466, 467, 468) in which they present, on the one side, select Clovis artifacts and, on the other, Solutrean artifacts. Here too, there are no detailed discussions of the broader context in which these lithics are found, and no solid empirical data presented in tables to back up their argument. Rather, the similarities between the composite pictures are, in this case as well, argued to represent indisputable evidence of a direct link between the two. Except that in this case, nobody else no seems to be convinced, beyond perhaps the popular press which is always so eager to present “both sides of the debate.”

As Clark (2004:110-111) argues:

“Their scenario is an example of post hoc accomodative argument, wherein explanations are developed after an analysis has been completed (in this case, a very superficial one) to account for patterns detected in a data set. Post hoc accomodation is a weak form of inference because the research designs that incorporate it lack a deductive component... Post hoc accomodative argument sets the agenda for future research, rather than constituting a set of conclusions that can stand or fall on their own.”

I think that this relatively fairly describes the gist of Mellars' approach as well. Now, I'm not saying that post hoc accomodative arguments cannot be a good source of ideas, some of which may even be amenable to empirical testing. However, in this case, there is very little analytical depth to this and Mellars' other recent papers (2006a, 2006c), and no critical take on the data. Rather, Mellars repeats the same argument over and over again, incorporating only the data that fits his ideas. The problem is that such papers are then taken as gospel by other researchers who cite it as proof for a single-origin colonizing population of modern humans that blazed an ochre-stained trail out of their African homeland as they marched ineluctably to conquer the rest of the world. Contemporary archaeology can – and most importantly should – do more than this, and develop its own set of conclusions that can then be confronted to the human paleontological and genetic records rather than vice-versa.

References

Bradley, D., and D. Stanford. 2004. The North Atlantic ice-edge corridor: a possible Palaeolithic route to the New World. World Archaeology:459-478,

Clark, G. A. 2004. Deconstructing the North Atlantic connection. In The Settlement of the American Continent (C.M. Barton, G.A. Clark, D.R, Yesner, and G.A. Pearson, eds.), pp. 103-122. The University of Arizona Press, Tucson.

Marks, A. E., 2003. Reflections on Levantine Upper Palaeolithic studies: past and present. In More than Meets the Eye: Studies on Upper Palaeolithic Diversity in the Near East (A. N. Goring-Morris & A. Belfer-Cohen, eds.), pp. 249-264. Oxbow Press, Oxford.

Mellars, P. 1996. The Neanderthal Legacy. Princeton University Press, Princeton.

Mellars, P. 2004. Neanderthals and the modern human colonization of Europe. Nature 432:461–465.

Mellars, P., 2005. The impossible coincidence. A single-species model for the origins of modern human behaviour in Europe. Evolutionary Anthropology 14, 12–27.

Mellars, P. 2006a. Why did modern human populations disperse from Africa ca. 60000 years ago? A new model. Proceedings of the National Academy of Sciences 103:9381-9386.

Mellars, P. 2006b. Going east: new genetic and archaeological perspectives on the modern human colonization of Eurasia. Science 313:796-800.

Mellars, P. 2006c. A new radiocarbon revolution and the dispersal of modern humans in Eurasia. Nature 439:931-5.

Sellet, F. 1998. The French connection: investigating a possible Clovis-Solutrean link. Current Research on the Pleistocene 15:67-68.

Straus, L.G. 2000. Solutrean settlement of North America? A review of reality. American Antiquity 65:219-226.

Wurz, S. 2002. Variability in the Middle Stone Age lithic sequence, 115,000–60,000 years ago at Klasies River, South Africa. Journal of Archaeological Science 29:1001–1015.

More on interstratifications

There's a new paper in PNAS by J. Zilhão and colleagues which casts serious doubts on the empirical validity of claims by Gravina et al. (2005) for the presence of a Châtelperronian-Aurignacian interstratification at the site of Grotte des Fées de Châtelperron. This is the final version of a paper which was presented at the Paleoanthropology Society meetings in San Juan, Puerto Rico this past April, and John Hawks already has some good comments on it.

Empirically, there is little to argue with here, and the authors thoroughly and painstakingly debunk the evidence used by Gravina et al. (2005) in support of the alleged interstratification. They conclude that, by and large, the sequence at Grotte des Fées de Châtelperron appears to have been extensively disturbed postdepositionally and that its stratigraphy is too severely compromised for it to be used to reliably talk about the succession of Upper Paleolithic "cultures" in the area. The most damning evidence they bring to bear is the presence of typological diagnostics belonging to various technocomplexes in the layers that are at the center of the dispute. As well, there is indisputable evidence that carnivores accumulated the vast majority of the faunal assemblages of the site's levels germane to the debate, which given the dubious context of the lithics largely precludes their unambiguous association with human occupations at the site.

As concerns the lithic assemblages, they conclude that the scant number of retouched pieces relative to debitage (34.5% of the assemblage - a figure which is in actuality not all that low, but one that is consistent with the occupation of the site by residentially-mobile foragers or those on task-specific forays) and the extremely small number of Aurignacian diagnostics argue against interstratification. Most important, however, is the taphonomic study of the site's stone tools which clearly demonstrates that levels B1-3 are significantly disturbed, while levels B4 and B5 might be largely in place. Given this situation, it is more than likely, according to the authors, that the rare Aurignacian pieces (i.e., 5 pieces out of 237 total) are intrusive into B4. This is an excellent example of how taphonomic study of lithics can yield precious information about site formation processes and a further incentive for analysts to perform such studies in all contexts.

Overall, I like this paper a lot, and not only because it agrees with my colleagues and I's conclusions that Gravina et al.'s (2005) case is thoroughly unconvincing (Riel-Salvatore et al. 2006). This is the kind of critical evaluation of artifactual material that should go into any analysis of Paleolithic material, especially when dealing with such "hot button" topics as the Neanderthals' disappearance and/or their cognitve capacities. That said, as discussed in a previous post, I don't necessarily agree with Zilhão, d'Errico and their colleagues that these findings argues only for the 'indigenist' scenario of modern human origins. Considered in the broader context of Eurasia and of other kinds of interstratifications, the implications are much less straightforward than claimed in this paper. Specifically, with all the respect I have for the rigor of Zilhão and d'Errico's work and the important rejuvenation it has brought to 'Transition studies' so to speak, their perspective remains fundamentally a very culture-historical one where given artifact types can be equated directly with given "cultural" and even biological groups. While not inherently incorrect, this perspective largely discounts the fact that Pleistocene hominins made artifacts first and foremost to ensure their survival and maximize their reproductive fitness through the acquisition of the resources necessary to support them. I think that considering the transition from such an angle offers new, stimulating perspectives on the Transition that enable us to approach this evolutionary problem from the behavioral perspective necessary to cast it in the appropriate theroretical - and methodological - light.

References

Gravina, B., P. Mellars, C. Bronk Ramsey, 2005. Radiocarbon dating of interstratified Neanderthal and early modern human occupations at the Châtelperronian type-site. Nature 438:51-6.

Riel-Salvatore, J., A. E. Miller, and G. A. Clark. 2006. On the reality of a claimed Châtelperronian-Aurignacian interstratification at Grotte des Fées de Châtelperron (Allier, France). Paper presented at the 2006 Annual Meetings of the Paleoanthropology Society, San Juan, Puerto Rico.

Zilhão, J., F. d’Errico, J.-G. Bordes, A. Lenoble, J.-P. Texier, and J.-P. Rigaud. 2006. Analysis of Aurignacian interstratification at the Chaˆ telperronian-type site and implications for the behavioral modernity of Neandertals. Proceedings of the National Academy of Sciences 103:12643-12648.

New Predmosti finds

A recent report details the discovery, by Becky Farbstein of Cambdige University, of two small pieces of bone bearing incised lines at the site of Predmosti, in Moravia. Here's the only image of the finds I've been able to locate so far.

Accoridng to the timeline provided by the report (25-30 kya - no mention of whether this is in calibrated years BP), the finds would belong to the Gravettian (or Pavlovian, in East-Central Europe), an industry for which a rich body of artistic behavior is documented, especially in Moravia, where figurines, dolls, ornaments and rich burials are well-documented. Thus, two "thumbnail-sized" pieces of incised bone hardly represent a revolutionary find, though little new in the way of decorated artifacts had been found at Predmosti since the original excavations, about a century ago. Every little bit helps, though, when trying to understand the complexity of artistic behavior in the deep past. It'd be interesting to see if a similar find would have been published without additional expert commentary had it been made in Mousterian or even Aurignacian context...

The ongoing Kansas shuffle...

So, the Kansas board of education got a makeover again yesterday, as related in this story in the NY Times.

Seems like a good thing, at least for the short term... it'd be better if we could ultimately enact a more lasting solution than the current political see-saw between moderates and advocates of non-scientific approaches, however. Carl Zimmer has a good, interesting post on the ruling.

Be back soon!

Hey folks.
Sorry for the lack of updates. I'm back in AZ and currently in the throes of moving to a new place, which is monopolizing my time. I should be back posting regularly within a week or so.