Wednesday, December 08, 2010

Front Range Neanderthal Workshop - UC Denver, Dec. 11

In one of my last posts, I mentioned in passing that I'm hosting a workshop on the UC Denver campus this coming Saturday, Dec. 11, 2010. The event - the Front Range Neanderthal Workshop - is to be held in the historic Tivoli Building which currently serves as the student union on our campus (but used to house the Tivoli Brewing Company and still is the only place you can get a beer on campus these days).

The rationale for the workshop is pretty simple: there's quite a few people doing Neanderthal/Paleolithic research within about a two-hour drive from Denver, all of whom are doing really interesting research. In fact, I'd even go as far as saying that the density of Neanderthal specialists along the Front Range is among the highest outside of Europe. Yet, for a variety of reasons, we rarely come together to take full benefit of each other's expertise or bounce ideas off of one another. Sure, nowadays, you could argue that face-to-face interaction is not necessary, but my view is that nothing replaces direct interaction.

So with that in mind, I invited colleagues from my own institution, CU Boulder, Colorado State University (where I had a wonderful time when I gave a talk there last month - thanks to Chris and Mica for setting it up!), UC Colorado Springs, Denver Museum of Nature and Science and the University of Wyoming, to congregate on the UC Denver campus so we can give each other an overview of and comment on our ongoing research. As well, I've invited students to present posters on some of their own project, so that they can get some feedback on their ongoing projects from specialists in the field. Here's the program of the day:

9:15 - The Middle and Upper Pleistocene Record of Western Europe and South Africa: Similarities and Differences.
P. Villa, CU Museum of Natural History

9:40 - How to Think like a Neandertal.
T. Wynn & F. Coolidge, UC Colorado Springs

10:05 - The Paleobiogeography of Central Asia: Addressing the Validity of a Neandertal Range.
M. Glantz, Colorado State University

10:30 Coffee break

10:45 - 'Necessity is the Mother of Invention': Late Neanderthal Cultural Innovation in Context
J. Riel-Salvatore, UC Denver

11:10 - The Neandertal-Modern Human Biocultural Transition in South-Central Europe: The Evidence From Croatia.
J.C. Ahern et al., University of Wyoming

11:35 - The Early Upper Paleolithic of Eastern Europe Reconsidered..
J.F. Hoffecker, CU Boulder

12:00 - The Upper Paleolithic Levels at Ksar Akil, Lebanon, and the Levantine Aurignacian.
J. Williams, SWCA

12:30 - Student poster session:

  T. Beeton et al.: GIS Modeling of Hominin Landscape Exploitation Strategies in Central Asia.

  L. Denton: The Internal Structure of Shovel Shaped Incisors Revealed.

   I.C. Ludeke et al.: Contrasting Neanderthal and Homo sapiens Use of Space at Riparo Bombrini, Italy.

  I. Riley et al.: Evaluating the Ballistic Properties of Levallois Points from ‘Ain Difla (Jordan).

  C.J. Tinti: Understanding Patterned Behaviors through the Analysis of Femoral Neck Torsion.

Two of these posters are by some of my own students, Ingrid Ludeke and Ian Riley, who are presenting preliminary results of really interesting projects we've been working on together for the past semester.

The talks and poster session are open to the public, provided interested parties register by contacting me directly (replace the dot by, well, dots!). There's also a roundtable in the afternoon that includes my UC Denver colleagues D. Tracer and C. Musiba, as well as S. Nash of the DMNS, but that is closed to the public. If you want more info, you can also download the program in pdf format.

In any case, here's to hoping I haven't jinxed the event by talking about it before it happens (they're predicting snow on Saturday morning, of course), but I really think it's going to be a lot of fun on top of being a great occasion to hear about some really forward-looking research by very active scholars in the field.

Café Scientifique postmortem


My Colorado Café Scientifique talk this past Monday went very well, with about 100 people crammed upstairs at Brooklyn's and firing off over an hour's worth of questions at yours truly. It was great fun, and many thanks to Eric Meer and John Cohen for all their hard work setting it up and running the two incarnations of Colorado Café Scientifique

If you live in the Denver and have an interest in science, definitely try to attend their lectures; I can guarantee you won't regret it. I also wasn't aware of this, but I was told that the Colorado Café is one of the biggest in North America, and its monthly talks are always very well attended. Yet another reason to like life in Denver!


Monday, December 06, 2010

Neanderthal innovation at tonight's Denver Café Scientifique

Hiya folks! Yes, I'm still alive, but have been incredibly, incredibly busy, a business that shows no sign of abating until December 11. Why December 11? It's when I'm hosting the Front Range Neanderthal Workshop on the UC Denver campus! But more on that in a but.

Focusing on the here and now, tonight, December 6 2010, at 6:30PM, I'm presenting an overview of some of my recent research on Neanderthal innovation and niche construction as part of the Denver Café Scientifique series. In their words, at the
"Café Scientifique, people (often science buffs) come together in a friendly pub after work and hear an informal (no PowerPoint!) introduction to an interesting current scientific topic, led by an expert. We take a short break for refreshments, to meet new people, and chat, and then we return for questions and answers and general discussion. All questions and comments are welcome, as this isn't a seminar, it's a chance for all of us to express an opinion, expert or otherwise."

So this is a non-technical talk (and powerpoint-free, to boot!) geared to an educated, but non-specialist audience. The talk's titled "So Easy a Caveman Could Do It: Neanderthals Innovated Independent of Modern Humans." So if Neanderthals float your boat, or if you'd like to learn about them, by all means, come down. The event is free and open to the public, at it starts at 6:30PM at Brooklyn's, just North of the UC Denver campus. So if any Denver-area readers want to come and meet, I'll be there and would love to meet you!

PS: To the readers who left comments on my post about my recent JAMT paper, thank you! I haven't forgotten about you, and I'm hoping to be able to provide replies in short order.


Thursday, September 30, 2010

Important Science!

Talk about some scientific research I get behind!

"These findings might help brewers in devising fermentation processes in which the release of yeast proteins could be minimized, if such components could alter the flavor of beer, or maximized in case of species improving beer's aroma," the report notes.

In fact, I'm sure quite a few archaeologists might be interested in this... In other beer-y news, I was finally able to sample Tut's Royal Gold after Todd Surovell's colloquium talk last Friday. It reminded me of a slightly bitter Hefeweizen, but it was pretty good. Can't beat that for an archaeologically-themed beverages.


Tuesday, September 28, 2010

Independent Neanderthal Innovation - Some Additional Considerations

One of my upcoming papers (Riel-Salvatore 2010) was written-up in a series of mainstream news outlets, including the New York Times, the BBC, Discovery News, AOLNews, MSNBC and sundry others. The original, reproduced in Science Daily, was published under the headline "Neanderthals More Advanced Than Previously Thought: They Innovated, Adapted Like Modern Humans, Research Shows." In the original UC Denver press release, ResearchBlogging.orgI'm quoted as saying, among other things, that this study helps 'rehabilitate' Neanderthals by showing that they were able to develop some of the accoutrements of behavioral modernity independent of any contact with modern humans. While I've caught a bit of flak from some friends and colleagues for that turn of phrase, I stand by my statement -this study helps to cast Neanderthals in a much more positive light than they have been for a long while now.

In any case, it's always exciting to see your work written-up, but also a bit daunting. In a few days, I'm going to try to put together a post on the whole 'going to the press' experience, but I figured I'd seize the opportunity to provide a bit more detail on the paper currently making the rounds in various news outlets, to clear up confusion and preemptively answer some of the questions it might raise. Here goes...


So,  what is it I did? The short answer: I showed that, among, other things, around 42,000 calendar years ago (ca. 36.5 radiocarbon years BP), a new culture (better, behavioral adaptation) - the Uluzzian - emerged in southern Italy and is widely believed to have been made by Neanderthals. The thing is, the Uluzzian is associated with bone tools, stone armatures likely used as part of composite projectile weapons, shell ornaments, coloring material (ochre, limonite), and possible evidence of small game exploitation. These features are all generally associated with modern human groups, not so much with Neanderthals. Because the timing of the origins of the Uluzzian matches that of the appearance of the Aurignacian generally attributed to modern humans, many people (e.g., Mellars 2005) have argued that the Uluzzian was the result of Neanderthals being acculturated by modern humans, and creating hybrid cultures that ultimately proved to be too little, too late for the Neanderthals.

Here's the rub, though: for acculturation to be a likely explanation, two conditions need to be met, proximity in time (i.e., they need to overlap in time) and proximity in space (they need to be found next to one another). As I show in the paper, for the Uluzzian, while proximity in time to the Aurignacian is established, proximity in space isn't. That's because when the earliest Aurignacian appears in northern Italy and the Uluzzian appears in southern Italy ca. 42,000 years ago, the center of the Italian peninsula is occupied by Neanderthals making the Mousterian tools they'd been making for over 100,000 years. So, in essence, you have a 'Mousterian buffer' (and a long-lasting one at that) between the regions where the Aurignacian and Uluzzian develop. If the acculturation scenario was right in this case, you would expect the Uluzzian to first spring up immediately next to where you find the Aurignacian. Since the condition of proximity in space is not satisfied, it is very unlikely that acculturation is the explanation for the origins of the Uluzzian.

Given that the Uluzzian is assumed to have been made by Neanderthals, this implies that Neanderthals developed it on their own, independent of modern human influence. If that's the case, though, a natural follow-up question is why the Uluzzian should emerge at the same time as you first see the Aurignacian implant itself in northern Italy. To answer this, in my view, you have to consider the ecology of that time period. To keep it short, it's one of the most climatically turbulent periods of the Late Pleistocene, which was climatically turbulent to begin with. In southern Italy, this translated into cooler, more arid conditions that stand in contrast to the Mediterranean scrub-woodland that characterized the region earlier. Given the suddenness with which conditions shifted between one and the other (there was a lot of fluctuation), people would have had to develop behavioral strategies that allowed them to cope with uncertainty so as to minimize the risk of not being able to find the resources they needed to survive. The Uluzzian seems to fit that description, what with stoneworking strategies that minimize production waste; new tools that would have allowed people to better hunt at a distance; mobility patterns that reflect a conscious effort to provision hospitable spots with resources they may have lacked; the exploitation of a wider range of animals; and the development of artifacts to ease social friction when other groups were encountered.

It's hard to establish with certainty a link between paleoenvironments and behavioral innovation. In fact, naysayers would probably point out that Neanderthals were perfectly able to survive shift of the magnitude of those documented ca. 42kya. That's true but it ignores the fact that what Neanderthals hadn't been faced with previously, however, is the close spacing at which these fluctuations started happening ca. 42kya (Finlayson and Carrion 2007) - that was something new, and something that would stress any population, setting the stage for a moment where technological innovation could have been selected for. Now, this is an interpretation based on correlation as opposed to causation; however, any explanation for the origins of the Uluzzian (and the Aurignacian in northern Italy for that matter) that doesn't at least take them into consideration is likely oversimplistic.

Overall then, what I'm proposing in this paper is that climatic instability selected for behavioral innovation, one manifestation of which was the Uluzzian in southern Italy. If Neanderthals are responsible for the Uluzzian, that means they reacted in very 'modern' ways to these conditions by developing some of the very same innovations that seem to have made modern humans so evolutionary successful in the long term.

On to the preemptive questions and answers to them...

OK, but the paper's 33 pages long, is that all you're saying?


The short answer to that is no. The paper is an effort to use niche construction theory (Odling-Smee et al. 2003) as a conceptual framework in paleoanthropology to yield new insights on how to best integrate behavioral, ecological and biological evidence. It's by using that approach, however, that I'm able to propose an alternative explanation for the emergence of the Uluzzian that accounts for its timing, the lack of spatial proximity to the Aurignacian, and the paleoecological evidence. Because it explains more of the evidence, I argue that it's a much more parsimonious explanation than any of the ones that have been proposed in the past, which mostly focus on social factors.

The main advantage of using NCT as a conceptual framework here is that it encourages people to move beyond the identification of single prime movers to explain the Middle-Upper Paleolithic transition and the eventual disappearance of Neanderthals from the fossil record. Specifically, I argue that it's only by documenting the changing relationship between behavioral, ecological and biological dimensions of the record that we're likely to get at how this process really unfolded. In this case, I suggest that we can identify three phases of the transition interval, each of which is characterized by distinct dynamics between these three systems of inheritance, that are in part influenced by the interactions between them in earlier phases.

I get it... so is this the same mechanism that accounts for the origins of the Chatelperronian of the Franco-Cantabrian region?

Not exactly. The situation of the Chatelperronian, another 'transitional' industry attributed to Neanderthals and for many decades argued to be the result of their acculturation by modern humans, is slightly different. In that case, the condition of proximity in space is met. In other words, you find Chatelperronian sites in and next to regions where Aurignacian assemblages are found. What people like d'Errico and Zilhao have shown, however, is that the condition of proximity in time is not met, since the earliest Chatelperronian appears to predate the appearance of the Aurignacian in those regions by several thousand years (d'Errico et al. 1998, Zilhao 2006).

Therefore, while an origin independent of modern human influence can be postulated for both the Uluzzian and the Chatelperronian, the evidence for why this is the case is different in the two cases. For the Uluzzian, the reason is that, geographically, its only neighbors appear to have been Neanderthals. It is perhaps not surprising that a consideration of ecological conditions has come to the forefront in models for the development of these 'transitional' industries, which are called transitional, because they fall within the interval of the Middle-Upper Paleolithic transition, starting some 45,000 years ago.

But wait! Aren't there reports of Uluzzian occupations in northern Italy? How does this affect your conclusions?

Peresani and colleagues have recently been making a case for an Uluzzian presence in level A3 and A4-I at Grotta di Fumane, in the Veneto region of NE Italy (Peresani 2008; Higham et al. 2009). I talk about Fumane briefly in the paper, but let me discuss it in a bit more depth here. These are intriguing data. I've seen the material described as Uluzzian presented at a conference but I'm still uncertain about how closely it compares to what is found in southern Italy, since I haven't had a chance to see a detailed typological and technological publication of these objects and since I don't feel right using figures/numbers based on ongoing analyses that I've only seen fleetingly during a talk. Chronologically, they'd fit right in, no question. But there are a number of possibly contemporaneous assemblages in northern Italy associated with some evidence bipolar technology and with backed knives that somewhat resemble Uluzzian crescents (e.g., La Fabbrica, Paina) but that otherwise more closely align themselves with Late Mousterian assemblages, notably La Fabbrica (Bietti and Negrino 2007). So for the time being, it's not really possible to exclude that the Fumane assemblages claimed to be Uluzzian belong to this distinctive Mousterian tradition.

That said, let's consider for a moment what it might mean if Fumane A3 and A 4-I were to be shown to be Uluzzian. For one thing, it doesn't invalid the gist of what I have argued, namely that the Uluzzian could very well be an independent development. That's because in this case, while the condition of spatial proximity would be met (i.e., there are Aurignacian assemblages in the vicinity), the condition for proximity in time wouldn't since the earliest Uluzzian (dated to about 43,000BP) predates any Aurignacian assemblage in the region by as much as 2,000 years (Higham et al. 2009). Furthermore, the Uluzzian in southern Italy lasts until almost 35,000 calibrated years BP, while it would seem to not last beyond 40,000 BP at Fumane. This raises the question of the relationship of the Uluzzian in the two regions, and why it isn't found at all in Central Italy. Could the Uluzzian have originated in northern Italy? If so, how did it reach southern Italy? One obvious explanation would be to argue that people with Uluzzian technology sprinted down the Northern Adriatic Plain exposed during OIS3. However, since that area is now under water, we're unlikely to ever be able to demonstrate this one way or the other. Additionally, it still doesn't explain why Central Italy wouldn't have been explored by these people. The argument that they stuck to the coast is pretty weak in light of the fact that in southern Italy, Uluzzian assemblages are found along the Western coast of the Salento peninsula in the Bay of Uluzzo, and in southwestern Italy, in the foothills of the Alburni Moutains.

One possible explanation is that the Uluzzian originated somewhere else and diffused both in northern and southern Italy from that original homeland. The assemblage from Level 5 at Klisoura Cave, Greece has been proposed as one such potential source of origin. There are two problems with this, however: First, technologically, Klisoura 5 is very different from the Uluzzian in southern Italy. Notably, it displays much less bipolar technology, an almost complete reliance on blade technology, many more microliths, and a different way of making microliths. Second, in light of new dates from Fumane, the timing might be a problem since the assemblages would be almost contemporaneous. Third, there is nothing even remotely resembling an Uluzzian assemblage between the Peloponnese and the Italian peninsula. On the basis of current evidence, then, there is little solid data on which to base a solid link between Level 5 at Klisoura and the Uluzzian as a whole (Papagianni 2009). If that's the case, there are currently no assemblages on which to base the notion of an extra-Italian origin of the Uluzzian.

I'll buy that. But if Neanderthals were so smart and able to innovate in the face of change, what happened to them and their Uluzzian culture?

That's a good question, and before I answer it, let me highlight a few things. First, the Uluzzian is by no means a flash in the pan... currently available dates indicate that it lasted some 7,000 years. If a generation lasts 20 years, that's 350 generation of 'Uluzzians' - that's a hell of a long time, if you think about it, almost as long as the entire Gravettian. That means that, just because it disappears doesn't mean that the Uluzzian wasn't a successful adaptation. So there's that. Second, what I propose in the paper is that the Uluzzian is ultimately supplanted by a series of assemblages that have traditionally been called 'proto-Aurignacian' (a label for the earliest Aurignacian along the Mediterranean coast), but that really bear little in common with 'proto-Aurignacian' assemblages from northern Italy. For one thing, the proto-Aurignacian is characterized by very high frequencies of retouched bladelets in their tool inventories. In fact, as I detail in the paper, formal tools in most proto-Aurignacian assemblages in northern Italy on average comprise about two-thirds retouched bladelets. "Proto-Aurignacian" assemblages in southern Italy, in contrast, comprise on average only about 25% of retouched bladelets. In fact the bladelet frequency of the most bladelet-rich southern assemblages doesn't even surpass that of the least bladelet-rich northern assemblage. In addition, southern Italian 'proto-Aurignacian' assemblages tend to be associated with proportionally more evidence of bipolar technology (an Uluzzian trait in the region). These observations suggest that whatever comes after the Uluzzian in southern Italy may not, in fact, be the same as the proto-Aurignacian in the north, but really more of an amalgam or a form of cultural 'middle ground' between the two traditions.

This means that the makers of the Uluzzian probably weren't dispatched by people making proto-Aurignacian technology. Rather, it seems they were probably absorbed in the growing population from the north that would have been slowly spreading southwards over many millennia. This 'incorporation' makes sense of both the archaeological record, fossil evidence that there was some interbreeding between modern humans and Neanderthals (Trinkaus et al. 2003), and recent genetic research that shows that Neanderthals contributed a small portion (1-4%) of modern non-African populations (Green et al. 2010).

I only see the dates you mention in support of your argument for a lack of geographical proximity graphed in Fig. 2. Are the raw dates available?

All of the dates used in Fig. 2 are already published (see Riel-Salvatore and Negrino 2009, Table 1), with the exception of a series of dates from Grotta del Cavallo. These are reported in my PhD dissertation (Riel-Salvatore 2007), which is available upon request. These new dates will soon be published in full with colleagues from the University of Siena. In the meantime, they're presented here in graphical form to underscore a point, but since they're not the central thesis of the paper, the raw dates are not included in the paper itself.

What about recent claims that the Chatelperronian wasn't made by Neanderthals? Do they have any impact on your conclusions? 

The short answer here is not directly. I'm the first one to admit that the fossil evidence for the 'transition interval' in Italy is extremely scant. The attribution of the proto-Aurignacian to modern humans is based on a couple of loose while the attribution of the Uluzzian to Neanderthals is based on three milk teeth from two layers in one site, Grotta del Cavallo. The only certainty seems to be for central Italy, where Neanderthal remains are associated with some of the Late Mousterian assemblages. In the past, the consensus view - no doubt in part informed by the Chatelperronian situation - has been that some of those teeth from Cavallo display some affinities to Neanderthals, in spite of the lowermost tooth originally having been described as more modern in appearance (Palma di Cesnola and Messeri 1967), although recent revisions suggest that it falls within the Neanderthal range (Churchill and Smith 2000).

Whatever the case may be, the fossil record is extremely thin here, and while people have traditionally been comfortable with the proto-Aurignacian = modern human and Uluzzian = Neanderthal equations, my own preference is to remain agnostic about who made what industry during the transition interval in the Italian peninsula (Riel-Salvatore 2009). However, because the generally accepted view is that the Uluzzian was made by Neanderthals, I've used it as an operating assumption in this new paper, even though I derive none of my hypotheses from that assumptions. In fact, I think that considering whoever made the Uluzzian first and foremost as foragers helps to avoid predetermining interpretations about what the Uluzzian was, how it came to be and how it disappeared.

That said, it's worth considering what the implications would be for my new paper of a modern human authorship. First, would it alter my main conclusion, that the Uluzzian was developed independent of proto-Aurignacian influence. Here, the answer is a clear no. Authorship has no fundamental impact on what the Uluzzian was. Even if it turned out to have been made by modern humans, it would seem to emerge in southern Italy independently of whatever was going on in the north at that time. The only wrench modern human authorship really would throw in my interpretation would relate to where those modern humans would have come from - in that case, people would probably start looking east towards Klisoura with renewed attention, but as I've detailed earlier, this is an unlikely source for the Uluzzian, unless we're willing to accept that modern humans diffused along the northern coast of the Mediterranean without a single defining industry. While not impossible, this scenario opens a whole new can of worms, though, because then you need to demonstrate the modern human authorship of everything between the Peloponnese and southern Italy, which would be no small feat.However, given that the homogeneity of most new cultures associated with modern humans during the transition is generally interpreted as a positive indication of their adaptability (Roebroeks and Corbey 2000), we'd then have to explain why this feature was not selected for in that specific region, and why/how the Uluzzian grew out of this strategy to last for several millennia. As a thought exercise, though, it is interesting to ponder the ramifications of what it might mean if the Uluzzian had been made by modern humans in the context of the traditional acculturation scenario, since Homo sapiens-Homo sapiens confrontation is not usually taken to be a feature of the transitions... (Riel-Salvatore 2009: 390-391)


OK, I'm posting this now so that it's available for interested readers to peruse in order to complement the press coverage this has been getting... if you have questions/comments, feel free to leave them below, and I'll answer them in short order... if they're substantive enough, I might even incorporate them in the list of questions comprised in this post!


References

Bietti, A. and F. Negrino. 2007. ‘‘Transitional’’ Industries from Neandertals to Anatomically Modern Humans in Continental Italy: Present State of Knowledge. In Transitions Great and Small: New Approaches to the Study of Early Upper Paleolithic ‘Transitional’ Industries in Western Eurasia, edited by J. Riel-Salvatore and G. A. Clark, pp. 41–59. Archaeopress, Oxford.

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

d'Errico, F., Zilhao, J., Julien, M., Baffier, D., & Pelegrin, J. (1998). Neanderthal Acculturation in Western Europe? A Critical Review of the Evidence and Its Interpretation Current Anthropology, 39 (S1) DOI: 10.1086/204689

FINLAYSON, C., & CARRION, J. (2007). Rapid ecological turnover and its impact on Neanderthal and other human populations Trends in Ecology & Evolution, 22 (4), 213-222 DOI: 10.1016/j.tree.2007.02.001

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

Higham, T., Brock, F., Peresani, M., Broglio, A., Wood, R., & Douka, K. (2009). Problems with radiocarbon dating the Middle to Upper Palaeolithic transition in Italy Quaternary Science Reviews, 28 (13-14), 1257-1267 DOI: 10.1016/j.quascirev.2008.12.018

Mellars, P. (2005). The impossible coincidence. A single-species model for the origins of modern human behavior in Europe Evolutionary Anthropology: Issues, News, and Reviews, 14 (1), 12-27 DOI: 10.1002/evan.20037

Odling-Smee, F.J., Laland, K.N. & Feldman, M.W. 2003. Niche Construction: The Neglected Process in Evolution. Monographs in Population Biology. 37. Princeton University Press.

Papagianni, D. 2009. Mediterranean southeastern Europe in the Late Middle and Early Upper Paleolithic: modern human route or Neanderthal refugium? In The Mediterranean Between 50-25,000 BP: Turning Points and New Directions, edited by M. Camps i Calbet and C. Szmidt, pp. 115-136. Oxbow, Oxford.

Peresani, M. (2008). A New Cultural Frontier for the Last Neanderthals: The Uluzzian in Northern Italy Current Anthropology, 49 (4), 725-731 DOI: 10.1086/588540

Riel-Salvatore, J. 2007. The Uluzzian and the Middle-Upper Paleolithic Transition in Southern Italy. Unpublished PhD Dissertation, Arizona State University, 351 pp.

Riel-Salvatore, J. 2009. What is a 'transitional' industry? The Uluzzian of southern Italy as a case study. In Sourcebook of Paleolithic Transitions, (M. Camps, P. Chauhan, eds.), pp. 377-396. Oxbow, Oxford. DOI 10.1007/978-0-387-76487-0_25.

Riel-Salvatore, J. (2010). A Niche Construction Perspective on the Middle–Upper Paleolithic Transition in Italy Journal of Archaeological Method and Theory DOI: 10.1007/s10816-010-9093-9

Riel-Salvatore, J. and F. Negrino. 2009. Early Upper Paleolithic Population Dynamics and Raw Material Procurement Patterns in Italy. In The Mediterranean Between 50-25,000 BP: Turning Points and New Directions, edited by M. Camps i Calbet and C. Szmidt, pp. 205–224. Oxbow, Oxford.

Roebroeks, W. and R. Corbey. 2000. Periodizations and double standards in the study of the Palaeolithic. In Hunters of the Golden Age (W. Roebroeks, M. Mussi, J. Svoboda and K. Fennema, eds.), pp. 77-86. Leiden University, Leiden.

Trinkaus, E. (2003). An early modern human from the Pestera cu Oase, Romania Proceedings of the National Academy of Sciences, 100 (20), 11231-11236 DOI: 10.1073/pnas.2035108100

Zilhão, J. (2006). Neandertals and moderns mixed, and it matters Evolutionary Anthropology: Issues, News, and Reviews, 15 (5), 183-195 DOI: 10.1002/evan.20110

Wednesday, September 22, 2010

Todd Surovell - Late Pleistocene Megafaunal Extinction talk at UC Denver, Friday Sept. 24

This Friday, September 24, 2010 (at 4:00PM in AD 200), the UC Denver Department of Anthropology is hosting a colloquium by Todd Surovell on Late Pleistocene megafaunal extinctions in North America. Details below.

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The Associational Critique and the Late Pleistocene Extinction of North American Megafauna

Todd A. Surovell
Associate Professor
Dept. of Anthropology, University of Wyoming

Abrstract

Humans first arrived in North America approximately 14,000 years ago. Over the next two millennia, some 35 genera of Pleistocene megafauna suffered extinction. While it is tempting to see causality in this chronological correlation, after more than 80 years of fieldwork concerning the Pleistocene human occupation of the Americas, we can only demonstrate with confidence that humans hunted at most five species of extinct fauna. Fundamentally then, we must ask if it is possible that humans caused the extinction of some 35 genera of large mammals but left behind very little evidence of that act? This question is at the heart of what I call the "Associational Critique" of the overkill hypothesis. Critics of overkill argue that anthropogenic extinction will remain highly controversial until unambiguous material evidence of human hunting of a large number of taxa is discovered. In contrast, I will argue that a huge amount of circumstantial evidence points to humans as the primary causal agents of extinction, and that the associational critique puts forth unrealistic if not impossible requirements for the overkill hypothesis to fulfill.

Friday, September 24, 2010 – 4:00PM
Room AD 200 (Administration Bldg., 1201 5th St.)
Hosted by the
UC Denver Department of Anthropology

Thursday, September 02, 2010

Quote of the day: Bears, scrapers and points, oh my!

I'm co-teaching a seminar on Neanderthals and the origins of modern humans at UCD this fall, and so far having a really good time. Today, I introduced the topic of Mousterian stone tool technology to my students, including this classic tip on how to distinguish convergent scrapers from Mousterian points...
"In fact, the major problem in classifying Mousterian points is distinguishing them not from other point types but from convergent scrapers... Bordes (1961) himself offered a light-hearted "functional" criterion, writing that the best way to decide is to haft the piece and try to kill a bear with it. If the result is successful, then it is a point; if not, then it should be considered a convergent scraper. One of the problems with this approach is that it can quickly exhaust the available supply of bears or typologists, depending on the nature of the assemblage." (Debénath and Dibble 1994: 62).

Reference

Debénath, A. and H.L. Dibble. 1994. Handbook of Paleolithic Typology Volume One: Lower and Middle Paleolithic of Europe. University Museum of the University of Pennsylvania, Philadelphia.

Friday, August 27, 2010

DIY knapping

The Scientific American blog has a short piece on how stone tools have been an integral part of human evolution for the past 3.4 million years. It's mostly a series of links to some articles featured on the online features of the magazine, but it's accompanied by this nifty video of Kyle Brown knapping:



Clearly, someone's very impressed at 1:58, when he knocks off a big honking flake! All kidding aside, I always enjoy videos like this, that really focus on the piece being knapped and zoom appropriately. They really do a wonderful job of showing the hand-eye coordination involved in flintknapping, as well as how much slight hand motion, control and feeling around is involved in the act... it's not just randomly bashing rocks, folks! And though Brown doesn't use gloves or anything to protect his hands in this demo (though notice the pad on his legs), for any novice knapper reading this, remember, in lithics as in love, use protection!

Thursday, August 26, 2010

Why flour matters

A couple of days ago, I mentioned how excavations at a Paleoindian site in Utah has revealed that the site's occupants had been milling various seeds to produce different kinds of flours. In that post, I mentioned how this discovery re-emphasized the fact that hunter-gatherers in general hunt as well as gather. In ResearchBlogging.orgfact, outside of the highest latitudes, plant foods often account for a majority of the caloric intake of ethnographically-documented forager groups, suggesting that this was also very likely the case in prehistory. This is an especially important realization for Paleoindian research, since public (and sometimes even academic) perception is that Clovis and Folsom foragers were essentially big guys with big spears killing big things, i.e., megafauna. Estbalishing that they were not only collecting plants but also processing some of them rather intensively (grinding is a very time-consuming activity, and so is the shaping of grinding implements) reinforces recent research that suggests that Paleoindian diets were as a whole much more diverse than is generally believed (Hill 2008).

Grinding plant matter into flour also has important other implications about the structure of hunter-gatherer subsistence and social life, however. To understand these, it's helpful to look at some of the earliest traces of flour production in the archaeological record, one example of which is provided by the Gravettian site of Bilancino, in Tuscany, Italy, which dates to about 25,000BP uncal. (Aranguren et al. 2007), and which I mentioned briefly earlier. Bilancino is a very interesting site: because of preservation issues, namely the acidic nature of the sediment there, no bone was preserved at all. This has forced the investigators to thoroughly investigate other kinds of archaeological remains that are not usually the focus of such intensive scrutiny in many Paleolithic studies. This includes notably charcoal, pollen and starch grain recovered from the surface of a grindstone. These efforts have paid off in spades by revealing that the occupants of Bilancino had been grinding cattail (Typha latifolia), likely its roots, as well as wild grasses to produce flour.

Aranguren et al. (2007) explicitly discuss the potential impact of flour on Paleolithic lifeways. They specificallyhighlight that it "implies the availability of an elaborate product, a flour, with high energy content, that is rich in carbohydrates, easily storable and transportable, to make a kind of bread (biscuits) or a porridge" (Aranguren 2007: 853). This means that plant material could be preserved and stored for much longer periods of time, which effectively can provide carbs during seasons such as winter during which they are normally difficult if not impossible to obtain. Also, it provides a subsistence items that serves as a buffer against the fluctuating availability of other types of subsitence resources, such as animal tissue. Lastly, because flour is easily ingested and digested, it also provides a foodstuff that both very young and very old members of a group can consume - and maybe even produce while adults are off procuring other things. This means that survival to adulthood and into old age can be facilitated, which has the potential of significantly reorganizing the way labor is divided within a society, and increasing the generational knowledge available to given forager groups.

References

Aranguren,Biancamaria, Becattini, Roberto, Mariotti Lippi, Marta, & Revedin, Anna (2007). Grinding flour in Upper Palaeolithic Europe (25000 years bp) Antiquity, 81 (314), 845-855

HILL JR, M. (2008). Variation in Paleoindian fauna use on the Great Plains and Rocky Mountains of North America Quaternary International, 191 (1), 34-52 DOI: 10.1016/j.quaint.2007.10.004

Tuesday, August 24, 2010

Location, location, location...

"I grew up in New Jersey. I might find a body, but not a prehistoric animal."

- Jim Leyden of Brighton, Tenn., on finding a mastodon skeleton while digging in his backyard earlier this summer.

Anthropological items of note, Aug. 24 edition

A few items of note, not all paleo-related, that grabbed my attention over the past couple of days:

  • There's an intriguing report at Slate about the lone survivor of an 'uncontacted' (a term I abhor) native tribe in Brazil that was decimated by ranchers and loggers. The man now live in almost complete isolation in a 31-squared-mile 'safe zone' monitored by government official.The report includes an interesting allusion to ethnoarchaeological  observations on a series of huts that allowed officials to estimate the size of hiss original tribe and pinpoint the year, 1996, they were eradicated by land-settler. Chilling.
  • Gizmodo offers an interview with Timothy Taylor who discusses some aspects of his upcoming book The Artificial Ape: How Technology Changed the Course of Human Evolution. The beginning of the exchange is wrapped in one of those annoying "Darwin was wrong" tropes that is completely misleading, but the rest of the piece presents an good overview of Taylor's view that human tool-use is radically different than any behavior observed in other animals. I should have more to say about this soon.
  • BYU archaeologist Joel Janetski and his team have found evidence that prehistoric foragers ground seeds and plants into flour some 10,000 years ago at North Creek Shelter, in Utah. The milled seeds include sage, salt bush and various grasses, which were processed on grindstones. The discovery provides evidence that Paleoindian diet may have been more varied than generally acknowledged by those who focus on the 'hunter' in 'hunter-gatherer'.
  • At Neuroanthropology, Greg Downey provides a long but very interesting discussion of Pat Shipman's new paper on the human-animal connection, focusing especially on the dog-human connection in human evolution.


Monday, August 23, 2010

Portrait of the artist as a Neanderthal

In a recent paper, O. Moro Abadia and M.R. Gonzales Morales (2010) argue that an important component of the 'multiple species model' (MSM) that sees Neanderthals as having essentially 'modern' behavioral capacities and that originated in the late 90's is based not so much on new discoveries as it is on new ways of looking at the ResearchBlogging.orgarchaeological record. Specifically, they make the case that part of why Neanderthals have become associated with artistic capacity signaling 'modern' behavior is a growing awareness over the past 30 years or so of the fact that personal ornaments and mobiliary (i.e., portable) art such as statuettes and engraved pieces are intrinsically symbolic in nature. This has resulted in what they claim is a paradigmatic shift away from considering cave art as the sole diagnostic of developed artistic (and by extension symbolic) capacities, to one that sees ornaments and mobiliary art as fundamental markers of that capacity. In turn, the association of Neanderthals with ornaments - based especially on Chatelperronian assemblages from Arcy-sur-Cure and Quincay - has likewise shifted the general perception of them towards a more 'human' prehistoric hominin over the past generation.

This is an interesting paper that makes some worthwhile points and provides some good food for thought. First, even though the idea of a Neanderthal authorship of the Chatelperronian has recently come under fire, the fact that pierced shells and coloring material have been found in even older Mousterian contexts renders moot the question of whether Neanderthals had the capacity to use and produce such technology in the absence of H. sapiens stimulus. Second, it's noteworthy that recent claims (i.e., in the past decade) about the much greater time depth of archaeologically visible traces of symbolic behavior in Africa are all based on this kind of evidence (e.g., engraved ochre at Blombos, early ochre use at PP13 and other sites, pierced shells in South and North Africa, etc.). In fact, prior to what Moro Abadia and Gonzales Morales consider the 'reconceptualization' of Paleolithic art, it was widely agreed that the Middle Stone Age and the Middle Paleolithic were very similar.

To their analysis, I would only add observations about two other aspects of the fundamental impact of considering ornaments as reflective of artistic and symbolic behavior. First, part of why personal ornaments and ochre became the focus of so much attention beginning in the 80's was that they were argued by people like Randy White to characterize the Aurignacian, in contrast to the Mousterian which lacked them (White 1992, 2006). This was in part driven by the observation that Paleolithic cave art was essentially absent from the Aurignacian record even though that technocomplex was argued to be the expression of the arrival of symbolically-enhanced modern humans in Europe. Even if one includes the Fumane and Chauvet art, we're hardly talking about a very abundant record, especially compared to later periods of the Paleolithic. Therefore, rightfully broadening the definition of 'art' to include personal ornaments at first distinguished Neanderthals from  modern humans, though that kind of evidence soon made it clear that Neanderthals also were symbolic beings, at least to an extent. In an unexpected twist, though, this reconceptualization of what is 'art' combined to a renewed interest in the MSA record during the 2000's ultimately ended up establishing that artistic behavior was a integral component of the behavior of at least some modern human groups much earlier than for Neanderthals as a whole.

My second observation is about the durability of ornaments. Ornaments are more resilient than cave art, since they don't need the exceptional preservation conditions of the latter to preserve in the archaeological record. If bones are present in a Paleolithic deposits, odds are that any associated ornaments made of, say, ivory, will also preserve, unlike most cave art which requires unusually stable temperature and humidity to preserve longer than a few hundred years.  By extension, considering ornaments 'art' means that, on purely probabilistic grounds, the first expressions of symbolic behavior would be traced back much further in time than if only identified on the basis of parietal art. The recent discoveries in Africa pushing ornament use to about 82kya clearly underscore the underappreciated importance of their sheer relative durability although, unlike for parietal art, human agency in perforating these early shells needs to be demonstrated rather than assumed.

Clearly, then, the authors are right in emphasizing the impact on paleoanthropological research of redefining Paleolithic artistic behavior to include personal ornaments (and portable art more broadly). This is true for an even wider range of reasons than even they discuss. I like this snippet of their concluding paragraph, which I think neatly sums up one of their fundamental points:

"While some specialists have a tendency to believe that science develops through the accumulation of discoveries and inventions, the MSM illustrates how scientific research is also influenced by theoretical paradigms that generate and sustain knowledge, determining the questions that are asked and those that are excluded. The latter statement does not imply that science is exclusively driven by conceptual propositions. Rather, we suggest that conceptual, technical and factual developments are interlinked... We have focused upon the theoretical dimension of the new discourses about Neanderthals and art to argue that scientific developments are not part of an ever-growing piecemeal process, but one influenced by a set of factual discoveries, previous knowledge, current beliefs and disciplinary paradigms."

References

MORO ABADÍA, O., & GONZÁLEZ MORALES, M. (2010). REDEFINING NEANDERTHALS AND ART: AN ALTERNATIVE INTERPRETATION OF THE MULTIPLE SPECIES MODEL FOR THE ORIGIN OF BEHAVIOURAL MODERNITY Oxford Journal of Archaeology, 29 (3), 229-243 DOI: 10.1111/j.1468-0092.2010.00346.x

White, R. (1992). Beyond Art: Toward an Understanding of the Origins of Material Representation in Europe Annual Review of Anthropology, 21 (1), 537-564 DOI: 10.1146/annurev.an.21.100192.002541

White, R. (2006). The Women of Brassempouy: A Century of Research and Interpretation Journal of Archaeological Method and Theory, 13 (4), 250-303 DOI: 10.1007/s10816-006-9023-z




2010 Loveland Stone Age Fair

The 2010 Stone Age Fair will be held in Loveland, CO, on Sept. 25 and 26. Although I wasn't planning on going, in the end, I was able to make it to last year's 75th edition, and it was a lot of fun and a great way to learn about Paleoindian archaeology and Colorado archaeology generally. I'm definitely planning to attend this year's Fair, which also will include the following two presentations:

Building a Paleoindian Research Program in Southeastern Idaho & Northern Utah
Bonnie Pitblado

For historical reasons, virtually nothing is known about the Paleoindian record of southeastern Idaho and northern Utah. However, in this region, four major physiographic zones converge—the Central Rockies, Great Basin, Columbia Plateau, and Wyoming Basin—creating an exceptionally diverse and inviting environment. Four years of foundational fieldwork has begun to reveal that the Paleoindian record of the region, like its environment, is diverse…and very inviting!

A Folsom winter campsite in the Colorado Rockies
Todd Surovell

Excavations at Barger Gulch Locality B in Middle Park Colorado have produced a rich assemblage of Folsom artifacts occurring within clusters associated with hearth features. Large scale excavations at the site over a 10 year period have allowed us to identify a number of aspects of Folsom spatial and social behavior.

Regular AVRPI readers might remember that some of Surovell's research on the effectiveness of wooden vs. stone projectile point tips was discussed earlier on this blog (and featured on Mythbusters!). In addition to the talks, there will be artifact displays, and the great Bob Patten (who was kind enough to come show Lithic Analysis students how to knap this past srping) will be doing a flintknapping demo, while Bob Heid will be making beads.  Find out all the details about this year's Stone Age Fair, including directions and a schedule of event, by visitng their website.


Friday, August 20, 2010

Paleolithic whodunnit: Who made the Chatelperronian?

The Chatelperronian is a lithic industry that springs up for several thousand years during the transition from Middle to Upper Paleolithic industries. Its precise age is debated, but it clearly is associated with this interval. One of the reasons the Chatelperronian is the subject of so much debate is because, since the ResearchBlogging.orgdiscovery of a Neanderthal in a Chatelperronian level at the site of
St. Césaire in 1978, it has widely been believed that Neandertals were the makers of this industry. This is important because up to that point, the Chatelperronian had been considered a true 'Upper Paleolithic' culture. Since the Upper Paleolithic had been thought to correspond to the arrival of modern Homo sapiens in Europe, the St. Cesaire discovery - and the association of Neanderthals with the Upper Paleolithic - meant that this association needed to be rethought. This has led to two main perspectives: those who see the Chatelperronian as an independent development by Neanderthals (d'Errico et al. 1998), and those who see the Chatelperronian as the result of the acculturation of Neanderthals by modern humans (Mellars 2005). The key thing here is that, in spite of much acrimonious debate between the two perspectives, both fundamentally attribute the Chatelperronian (and other coeval 'transitional' industries like the Uluzzian and Szeletian) to Neanderthals.

This may be about to change. In a short paper in press in the Journal of Human Evolution, Bar-Yosef and Bordes (2010) question this fundamental association in light of a revision of the two sites on the Neanderthal-Chatelperronian association is based: Grotte du Renne at Arcy-sur-Cure, and St. Césaire at La Roche à Pierrot, both in France. At Grotte du Renne, the authors suggest that the Neanderthal remains were incorporated into Chatelperronian deposits as a result of that layer's occupants digging into the Mousterian layer when they first settled into the cave. Thus, the Neanderthal bits would come from the Mousterian levels below. To them, such mixing is indicated by 1) the position of the remains (near the cave mouth) where dug up dirt would have been dumped, 2) the presence of a dug hearth indicating digging did take place, 3) a decrease in the number of teeth from the bottom to the top of the Chatelperronian levels, and 4) dicrepancies between radiocarbon dates and the stratigraphy of the late Mousterian and Chatelperronian layers.I think this is a fair argument, especially considering that the site was excavated prior to the establishment of the complete excavation methods used today, as the authors also underline.

At St. Césaire, where the the secondary burial of a Neanderhal was found in the Chatelperronian, Bar-Yosef and Bordes argue that the presence of distinct 'Mousterian' and 'Chatelperronian' components of the lithic industry and the fact that not all artifacts show a similar state of preservation suggest caution is needed before we can accept that it was not a mix of Mousterian and Chatelperronian levels. Because the burial is found in the upper (of two) Chatelperronian level, they argue that it was probably not deposited by occupants of the site anyway, implying that Neanderthals who did not make Chatelperronian tools might have buried one of their deceased at St. Césaire, perhaps in an effort to mark the site as theirs following the arrival of whoever made the Chatelperronian.

In my view, Bar-Yosef and Bordes' case is much stronger for Grotte du Renne than it is for St. Césaire, especially since bone refitting at St. Césaire has recently demonstrated that mixing between the Mousterian and the Chatelperronain was a negligible occurrence at the site (Morin et al. 2005). The need to invoke an explanation that doens't depend strictly on stratigraphic of artifactual data also weakens their overall argument. I say this because if their argument is followed to its logical end, it would mean that, even if you found that unheard of goody that would be a site containing only Chatelperronian layers and thus could exclude stratigrpahic mixing as an explanation, the presence of Neanderthal remains (or at least of a secondary Neanderthal burial) could still be explained away as a result of self-affirming Neanderthals claiming a stake to a given bit of territory. That's not to say that it's impossible, of course, and I will concede that the St. Césaire burial is the only relatively undisputed case of a Neanderthal secondary burial, so the practice was never common and who knows what it really might have meant, as the authors concede. Given that this is the case, though, you wouldn't expect a very unusual behavior to be the preferred manner in which Neanderthals would have marked their territories in the context of encounters with new groups of hominins.

In any case, Bar-Yosef and Bordes raise the specter that Neanderthals may not have been the makers of the Chatelperronian. They're circumspect in their conclusions of what this might mean, suggesting that archaeologists "should therefore start afresh, testing hypotheses about the hominins responsible for the formation of Chatelperronian contexts" rather than assume anything about their makers based on the potential unfounded assumption that they were Neanderthals. This is a view that I have a lot of sympathy for, having myself argued for the need for a similar perspective when interpreting the Uluzzian 'transitional' industry of southern Italy (Riel-Salvatore 2009, 2010 - go ahead, treat yourself and click, you'll find free pdfs). Ultimately, though, the revision proposed by Bar-Yosef and Bordes needs to be taken cautiously, especially as it concerns the St. Cesaire remains. One thing it doesn't do is associate the Chatelperronian with modern humans, though that's certainly one of the possible correlates of their paper, especially when they rail against 'continuity models' of human evolution in their conclusion. That said, if this revision and others like it have the beneficial result of getting people to carefully excavate and document new sites bearing 'transitional' assembalge, I'm all for them!


References:

Bar-Yosef, O., & Bordes, J.G. (2010). Who were the makers of the Châtelperronian culture? Journal of Human Evolution DOI: 10.1016/j.jhevol.2010.06.009

d'Errico, F., Zilhao, J., Julien, M., Baffier, D., & Pelegrin, J. (1998). Neanderthal Acculturation in Western Europe? A Critical Review of the Evidence and Its Interpretation Current Anthropology, 39 (S1) DOI: 10.1086/204689

Mellars, P. (2005). The impossible coincidence. A single-species model for the origins of modern human behavior in Europe Evolutionary Anthropology: Issues, News, and Reviews, 14 (1), 12-27 DOI: 10.1002/evan.20037

Morin, E., Tsanova, T., Sirakov, N., Rendu, W., Mallye, J., & Lévêque, F. (2005). Bone refits in stratified deposits: testing the chronological grain at Saint-Césaire Journal of Archaeological Science, 32 (7), 1083-1098 DOI: 10.1016/j.jas.2005.02.009

Riel-Salvatore, J. (2010). A Niche Construction Perspective on the Middle–Upper Paleolithic Transition in Italy Journal of Archaeological Method and Theory DOI: 10.1007/s10816-010-9093-9

Thursday, August 19, 2010

The final (?) word on those handaxes from Crete

While everybody was busy talking about unexpectedly old cutmarks and other Pleistocene goings-on last week, the paper by Strasser et al. (2010) describing the discovery of quartz handaxe assemblages on Crete ResearchBlogging.orgquietly came out in Hesperia. This is a topic that was discussed at length on this blog, in several posts that generated a large amount of comments a few months back. The sticking point of all the arguments concerned the chronology of the handaxes, so without further ado, here's the money quote (Strasser et al. 2010: 185-186):

"The dating of the Palaeolithic in the Plakias region presents a considerable challenge, not least because of the long period of time that may have elapsed since the occupation of the earliest sites, during which postdepositional natural processes may have obscured the archaeological record. Additionally complicating the issue are the small number of sites, the lack of excavation, and the impact of modern development on the area, which has destroyed many sites.

Several approaches to dating were attempted, and our research on this topic continues. At Preveli 2, east of the Preveli Gorge, Palaeolithic artifacts are associated with a flight of marine terraces resulting from relatively high sea levels in the Pleistocene that were preserved by subsequent rock uplift. The lowest late Pleistocene marine terraces resulting from high stands of the sea at Preveli (14 ± 1 masl) and Schinaria (21 ± 1 masl) have 2-sigma calibrated radiocarbon ages of 45,400 ± 1,600 and 49,120 ± 2,890 years b.p., respectively, and are correlated with Marine Isotope Stages 3.3 and 3.4, both eustatic high stands. The higher terraces, at 59 and 96 masl, are unquestionably older. How much older? Assuming similar rates of rock uplift (1.4 ± 0.1 m/kyr) determined from the age-elevation relationships of the dated terraces at 14 and 21 masl, it is possible to estimate the approximate ages of the terraces associated with artifacts. This correlation provides an approximate age for the lithic artifacts. The higher terrace, at 96 masl, may belong to Marine Isotope Stage 5, possibly early 5e, ca. 110,000 b.p. Artifacts associated with the terrace at 59 masl could correlate with Marine Isotope Stage 5a, ca. 70,000 b.p. It should be stressed that these are rough approximations and these ages are probably minima that represent a terminus ante quem. If the uplift rate is changed, the terraces and the artifacts associated with them could be much older.

At Preveli 3, Preveli 7, Timeos Stavros 1, and Schinaria 5, Palaeolithic artifacts were found in outcrops of paleosols that exhibit the characteristics of the oldest maturity stage for such features, that is, Maturity Stage 6, or in geological terms, Marine Isotope Stage 6. Together these observations suggest an age of ca. 190,000–130,000 b.p. and serve as a terminus ante quem for the artifacts embedded within them. The stone tools were incorporated in the paleosols as part of a process described by Runnels and van Andel in Epirus: “the top of the Bt horizon itself would move gradually upward as a result of slow deposition, so engulfing any artifacts laid down on former land surfaces above it.” In other words, the Bt horizon, especially as much of the clay comes from eolian sources, will increase in thickness through time, slowly
engulfing clasts, such as stone tools, that were formerly in the A horizon.

In sum, the dating of the Palaeolithic sites is based on geological data derived from the study of marine terraces on the southwestern coast of Crete and our identification of paleosols, and these data place the Palaeolithic lithic artifacts firmly in the Pleistocene, ca. 130,000 b.p. or earlier. The chronology can be further refined, however, and a dating program
currently in progress may provide data for doing so." (references excised)

So, bottom line, the dating is largely indirect, but grounded by dated references points that provide a minimum age for the terraces where the handaxes were recovered. Interestingly, this indicates that these tools are, at most, 130,000 years old. Given that there do not appear to be more recent Paleolithic age (the rest of the implements reported in the paper are Mesolithic in age and techno-typology, which is an important discovery in and of itself), this implies that on current evidence, Crete was not occupied during the Late Pleistocene (ca. 130,000-10,000 BP). Why this was the case (and how an early colonization took place) is an interesting question that will need to be answered by future research.

In the meantime, here are a few take-away observations from the Strasser et al. (2010) report. First, on the basis of the drawing of the handaxes, these implements do appear to be human-made. Second, they are not isolated occurrences: the authors identified nine localities where these quartz tools were found, only three of which also yielded Mesolithic tools. This leaves open the possibility that the 'Paleolithic' sites represent task-specific components of the Mesolithic toolkit on Crete, but this is unlikely based on the association of handaxes with some of the terrace deposits described in the quote above. Third, as the authors indicate, this was not a case of a H. heidelbergensis (or a couple of them) washing onto Crete: the fact that nine sites (defined by the presence of a minimum of 20 stone tools) were found in a relatively small area indicates a somewhat sustained human presence on the southern coast of Crete. This does suggest that people got there purposefully (i.e., using some kind of watercraft), which leaves open the question of why Middle and Upper Paleolithic assemblages haven't (yet?) been found in the region or elsewhere on Crete (or any other large Mediterranean island, for that matter).

As a parting observation: one aspect of the discovery that definitely wasn't stressed in the media reports about these finds is how they were made. They were breathlessly reported as 'discovered' without much context. The authors actually set out to look for Mesolithic sites in southern Crete using a model developed for the Greek mainland that identified certain areas as having been most appealing for Mesolithic foragers. In other words, this wasn't a blind search for early stuff or simply a fortuitous discovery. Rather, it came about as the result of an explicit research design targeting some very specific questions. Good to see more of that in Paleolithic archaeology. 

References:

Strasser, T., Panagopoulou, E., Runnels, C., Murray, P., Thompson, N., Karkanas, P., McCoy, F., & Wegmann, K. (2010). Stone Age Seafaring in the Mediterranean: Evidence from the Plakias Region for Lower Palaeolithic and Mesolithic Habitation of Crete Hesperia, 79 (2), 145-190 DOI: 10.2972/hesp.79.2.145