Saturday, May 22, 2010
"30mila anni fa a Finale Ligure: Nuove acquisizioni sul Paleolitico della Caverna delle Arene Candide // 30,000 Years Ago in Finale Ligure: New insights on the Paleolithic of the Caverna delle Arene Candide."
Saturday May 29 2010, 15.30
Museo Archeologico del Finale
Chiostri di Santa Caterina in Finalborgo (Finale Ligure - SV)
So, if you're in southern France or northern Italy that day, definitely come by! Can't make it? You can read a bit about what we've been up to on UC Denver's Network site.
Thursday, May 13, 2010
I was very happy to see that Nando Piezzi has a very nice slideshow on Saepinum on Demotix, which also includes a brief description of the site. Definitely take a moment to check it out.
Tuesday, May 11, 2010
The results of the study have been published in two papers in the last issue of Science (Green et al. 2010, Burbano et al. 2010 - both free access), where you can also find a free online feature. that provides some context to the public unfamiliar with genetics and/or Neanderthals To get a better idea of the significance and the nuts and bolts of this new work, you must, must go over to John Hawks' blog for a very thorough discussion. I largely agree with his take on the reports and what they mean, but as I've argued elsewhere, we need to reconcile the genetics with the fossil, and especially the archaeological records. Just as there was a great deal of well-founded skepticism by some about 'X woman' a few weeks ago (something which I've been meaning to write about and hopefully will get to relatively soon), people need to come to grips with all of the available data, as opposed to considering one line of evidence as trumping all others. In other words, it's not because some people wear lab coats that their data by definition trump all other!
Among the findings, published in the May 7 issue of Science, is evidence that shortly after early modern humans migrated out of Africa, some of them interbred with Neanderthals, leaving bits of Neanderthal DNA sequences scattered through the genomes of present-day non-Africans.
"We can now say that, in all probability, there was gene flow from Neanderthals to modern humans," said the paper's first author, Richard E. (Ed) Green of the University of California, Santa Cruz.
In practical terms, I think this means that you will see a lot of people more sympathetic to a replacement position start arguing just that, that you need to reconcile these new genetic data with previous data that seemed to strongly support such a position (just how strongly is debatable, but besides the point here). Specifically, I think you'll see these people focus on caveats of genetic studies like they never have before, and latch on to less parsimonious explanations of the genetics as 'something that needs to be considered seriously' (in this case, though, the alternative interpretation is so much less parsimonious as to be untenable). Fundamentally, of course, there's nothing wrong with that; in fact, it's something I've argued for repeatedly both on this blog and in press (link to a free pdf on the Uluzzian). The key difference is that if people on both ends of the spectrum will (hopefully) begin playing by the same general rules.
Now, does this mean that it's time to do the Neanderthal victory dance (to quote Hawks) and to begin re-imagining the caves of Late Pleistocene Europe throbbing to the sweet rhythms of Barry White and Marvin Gaye? Well yes and no. Yes, there is no some fairly conclusive evidence that Neanderthals and modern humans interbred and yielded fertile offspring - this means that, from a purely biological standpoint, the two were part of the same species, Homo sapiens. But no, it does not directly answer the question of how and why Neanderthals ultimately disappeared. And also, NO!, "Let's get it on" is not now a sufficient way of thinking about the relationships between Neanderthals and early modern humans!
That said, in my opinion, the two papers papers (Greene et al. 2010; Burbano et al. 2010) have the potential to considerably change how Neanderthals are discussed, both in terms of how people approach the data and how the data is interpreted, which are slightly different things. First, the people, namely researchers involved in modern human origins research. For one thing, as I mentioned above, you're likely going to hear much more frequent calls to consider all the evidence available and how it agrees/disagrees. On the other, in order to best incorporate all the relevant data in interpretations, the debate should shift away from 'one size fits all' interpretations to interpretations that are more regional in scale. Whether or not any of this actually happens is another story, but these papers definitely have the potential of serving as game changers in the modern human origins debate.
What I find most exciting about the Green et al. (2010) study is that it provides a strong boost for the importance of archaeological evidence plays in understanding the process by which Neanderthals disappear. Quite simply, this is because the genetic data and the skeletal evidence (Trinkaus 2007) now both converge to show some significant degree of biological interaction between the two homminin populations. The thing is, genetics and physical anthropology informing us about the fact that such interaction took place, but they tell us comparatively in terms of how these interactions played out. This is where archaeology comes in, since it's the only way we have of getting at the various types of interactions Neanderthals and modern humans might have had and to remove the preconceptions implicitly imposed by the notion that they were two distinct species.
In practical terms, we should now thankfully be moving away from models that see Neanderthals as fundamentally different from 'us'. This means that there is little reason to continue depending on interaction models that see Neanderthals as merely 'copying without understanding' whatever different behaviors early Eurasian modern humans might have displayed. An extension of that is that if Neanderthals and modern humans interacted enough for the former to have contributed between 1-4% of the genetic material of people of non-African extraction today, the two groups must have been able to interact in a sustained manner, which rules out a scenario whereby rape plays a preponderant role (and plays on prevalent ideas of Neanderthals as the savage/dangerous other). This also has implications about communication between the two groups, by which I mean that they likely were able to speak to one another, as already suggested by both genetic and indirect evidence anyway.
Perhaps most interestingly is that the degree of genetic contribution of Neanderthals to modern human genetics also sheds some light about how intense the interactions might have been, and also what some of the demographic parameters of thee encounters might have been. The numbers do point to some kind of demographic imbalance, though it must also be remembered that genes, like culture, can sometimes diffuse into an area much in advance of the arrival of a new population (Eswaran 2002, Eswaran et al. 2005). In other words, modern human genes might have made their way into Neanderthal areas by virtue of Neanderthal-hybrid interactions as opposed to necessarily only through Neanderthal-modern interactions. What this means for how 'hybrids' might have been perceived or integrated in either population is open to debate, but is a debate that might well shift to the center of ongoing debates about the nature of interactions between prehistoric humans populations.
Burbano, H., Hodges, E., Green, R., Briggs, A., Krause, J., Meyer, M., Good, J., Maricic, T., Johnson, P., Xuan, Z., Rooks, M., Bhattacharjee, A., Brizuela, L., Albert, F., de la Rasilla, M., Fortea, J., Rosas, A., Lachmann, M., Hannon, G., & Paabo, S. (2010). Targeted Investigation of the Neandertal Genome by Array-Based Sequence Capture Science, 328 (5979), 723-725 DOI: 10.1126/science.1188046
Eswaran, V. (2002). A Diffusion Wave out of Africa: The Mechanism of the Modern Human Revolution? Current Anthropology, 43 (5), 749-774 DOI: 10.1086/342639
ESWARAN, V., HARPENDING, H., & ROGERS, A. (2005). Genomics refutes an exclusively African origin of humans Journal of Human Evolution, 49 (1), 1-18 DOI: 10.1016/j.jhevol.2005.02.006
Green, R., Krause, J., Briggs, A., Maricic, T., Stenzel, U., Kircher, M., Patterson, N., Li, H., Zhai, W., Fritz, M., Hansen, N., Durand, E., Malaspinas, A., Jensen, J., Marques-Bonet, T., Alkan, C., Prufer, K., Meyer, M., Burbano, H., Good, J., Schultz, R., Aximu-Petri, A., Butthof, A., Hober, B., Hoffner, B., Siegemund, M., Weihmann, A., Nusbaum, C., Lander, E., Russ, C., Novod, N., Affourtit, J., Egholm, M., Verna, C., Rudan, P., Brajkovic, D., Kucan, Z., Gusic, I., Doronichev, V., Golovanova, L., Lalueza-Fox, C., de la Rasilla, M., Fortea, J., Rosas, A., Schmitz, R., Johnson, P., Eichler, E., Falush, D., Birney, E., Mullikin, J., Slatkin, M., Nielsen, R., Kelso, J., Lachmann, M., Reich, D., & Paabo, S. (2010). A Draft Sequence of the Neandertal Genome Science, 328 (5979), 710-722 DOI: 10.1126/science.1188021
Tuesday, May 04, 2010
This is also significant because of what the Aterian is usually taken to mean in terms of prehistoric human adaptations. For some, it is associated with some of the earliest evidence for projectile technology, which confers the advantage of allowing prey to be brought down at a distance, hence minimizing the risks of hunting to whoever uses it (e.g., Shea 2006). Other researchers have also argued that some of the bifacial points associated with the Aterian "may be adaptive systems focused on hunting in grassland ecosystems" (Banks et al. 2006: 76, 78). Specifically, these authors have argued that such grassland ecosystems are established in North Africa (where the Aterian is found) beginning with Oxygen Isotope 5e, some 130,000 years ago, while before that bifacial lanceolate points are mostly found clustered much further to the SW. if the ages from Ifri n’Ammar are correct, then, this provides some evidence against a simple link between ecology and the emergence of the Aterian industry.
Also of interest is that the Aterian sequence at Ifri n’Ammar is reported to be some 6.3m thick, with much more recent Aterian levels as well. Here, it bears emphasizing that Aterian deposits about 82,000 years old elsewhere in Morocco, have been associated with pierced shells most likely used as personal ornaments, the earliest evidence for that behavior anywhere in the world (as I discussed previously on this blog). It is perhaps not surprising, then, that the site has yielded in more recent levels
"two Nassarius gibbosulus et Nassarius sp. shells used as ornaments by the Aterians. They are older than 80,000 years BP. Both are similar in size and display identical intentional perforations. Microscopic and mineralogical analyses have revealed wear traces clearly resulting from their having being worn as ornaments, and traces of red ochre with which they had been intentionally covered" (my translation).
Overall,if the preliminary findings reported in this press release are borne out by future publications, Ifri n’Ammar definitely looks like it offers the potential to greatly refine our understanding of the Aterian and its origins as a whole.
Banks, William E., Francesco d'Errico, Harold L. Dibble, Leonard Krishtalka, Dixie West, Deborah I. Olszewski, A. Townsend Peterson, David G. Anderson, J. Christopher Gilliam, Anta Montet-White, Michel Crucifix, Curtis W. Marean, María-Fernanda Sánchez-Goñi, Barbara Wohlfarth, and Marian Vanhaeren. 2006. Eco-Cultural Niche Modeling: New Tools for Reconstructing the Geography and Ecology of Past Human Populations. PaleoAnthropology 2006:68-83
Barton, R., Bouzouggar, A., Collcutt, S., Schwenninger, J., & Clark-Balzan, L. (2009). OSL dating of the Aterian levels at Dar es-Soltan I (Rabat, Morocco) and implications for the dispersal of modern Homo sapiens Quaternary Science Reviews, 28 (19-20), 1914-1931 DOI: 10.1016/j.quascirev.2009.03.010
Shea, J. (2006). The origins of lithic projectile point technology: evidence from Africa, the Levant, and Europe Journal of Archaeological Science, 33 (6), 823-846 DOI: 10.1016/j.jas.2005.10.015