Cavemen, quadrupeds and science, oh my!

So... there's a new paper in PLoS ONE about how 'cavemen' depicted four-legged animals better than 'modern' artists (Horvath et al. 2012). I usually try to refrain from paper bashing here, but there is such a high density of wrong (if not downright fail) in this one, that it's hard not to. Becky Farbstein agrees, and points out that:

1) anyone using the word 'cavemen' with a straight face in a scientific publication today cannot be taken to know anything about the time period in question;

2) the paper's conclusions are only surprising or noteworthy if you assume that cavemen (and by extension hunter-gatherers) are somehow less advanced at a fundamental level than 'modern' folks (again, whatever that is);

3) and - extremely importantly - that there is no reason to expect that an artist, archaic or modern, necessarily operates with the goal of depicting quadrupeds realistically; to assume that this is the case fundamentally misinterprets what art can be and usually is, i.e., not strictly about representing reality.

Basically, as a friend said on Facebook, "With their methodology, you could argue that gravity was invented in the Renaissance because figures in 15th-century paintings begin to be grounded, rather than seeming to float as in Medieval art!" The same friend also added that that's why everyone needs to study at least some art history, but that's another issue (and for those readers wondering, I have [way] more than one snarky friend on FB).

I agree with all of this. However, another extremely problematic aspect that I haven't yet seen discussed concerns the data the authors use to make their case. Even if you disregard the points above, issues with the composition of their 'caveman art' sample data alone should be enough to laugh these people out of town. I was immediately suspicious when I saw the elephant image that accompanies the press release on the paper - an elephant is not usually what one associates with 'cavemen'. So I dug into their data, in the off chance they simply had an extensive sample of prehistoric art. After all, they boast about their data base being 1000 images strong. As it turns out, only 35* of those are 'prehistoric'. That's less than 4% of their total sample (I wonder how often they could bootstrap a similar trend from their modern sample just by randomly selecting 35 representations at a time...). But surely, these images all come from the same site or a handful of sites that date to the same period, right? Sadly, no: we're looking at 11 Paleolithic drawings (9 from Lascaux, one from Niaux, and another from Altamira) that span several thousand years and two countries. At least with those, a tenuous link to the idea of cavemen paintings could be made. But the 24 other representations come from sites scattered across Libya (consistently misspelled as 'Libia' in the paper, for crying out loud!), Morocco, various parts of India, and South Africa, with little if any chronological control. The point is that these pictures don't actually form a coherent body of evidence by any stretch of the imagination. Oh, and these conflate paintings, incisions, and engravings, all of which impose their own specific constraints on how art is produced. Add to that there is no reason to think that many of these representations were necessarily meant to be seen only in two dimensions or outside of the panels on which they were created (and in relation to the other designs these panels comprise), and you've got some of the shoddiest sample selection I have ever seen in a scientific paper.

I can't really figure out what their 'modern' sample is, but the issues with the prehistoric sample alone are enough to damn the paper. I don't care if they think that they can simply disregard context to focus on how walking was represented - the fact is you can't dissociate art from its context. Furthermore, with such a tiny and far-flung (temporally and spatially) sample of 'caveman' art, we can basically have no confidence at all that we're actually looking at how 'prehistoric' people represented animals, let alone their gait.

*Edit (Dec. 6, 2012; 11:43PM: Table 1 in the paper states a prehistoric sample of 39 'prehistoric' representations, whereas the supplementary information only details 35. Given this, I went with 35 being the most reliable value, since it's impossible to figure out what the other four representations were (of and from). Ultimately, however, using one or the other figure does not affect my point here - it's still less than 4% of the total sample, and a very small number of representation given the staggering geographic and temporal scales over which they are spread.

Reference:

Horvath G, Farkas E, Boncz I, Blaho M, Kriska G (2012) Cavemen Were Better at Depicting Quadruped Walking than Modern Artists: Erroneous Walking Illustrations in the Fine Arts from Prehistory to Today. PLoS ONE 7(12): e49786. doi:10.1371/journal.pone.0049786 (Link)

More paleo-porn fun!

Hot on the heels of my recent paleo-porn post, here's a wonderfully sarcastic - and dead-on! - comment about the post that I received on my Facebook.

Can I just say/rant one thing that always irritates me about Venus figurines and art with respect to sexuality/repro in the past is the conceit that saying "they were concerned about reproduction, or it was a focus" whatever is somehow supposed to be an interesting observation. Tell me about a culture that doesn't have some concern, taboos, mores about reproduction, etc. for god's sake. Other than sexy sexx sexxy sex-time sex sex sex titillation, what is so interesting about it? Hey, did you know that faunal remains indicate that people in the past ate food? No, listen, they literally ate food, with their mouths.

And, really, I couldn't agree more: To state that Venus figurines are evidence that Upper Paleolitic folks people cared about sexuality is kind of ridiculous. Of course they did in one way, shape or form, - and we certainly don't need Venus figurines to determine this.

Still on the topic of the paleo-porn story, also make sure to check out Becky Farbstein's post about the story - it touches on a lot of the same issues I originally raised.

A Sum Greater Than Its Parts: Multi-Disciplinary Perspectives on Later Human Evolution

What are you doing this weekend? If you're in the San Francisco area, you should come to the AAAs, specifically to attend this session I'm in entitled "A Sum Greater Than Its Parts: Multi-Disciplinary Perspectives on Later Human Evolution." It's being organized by Jamie Clark (University of Alaska Fairbanks) and Adam Van Arsdale (Wellesley College), and it will be jam-packed with human evolutionary goodness. Both Adam and John Hawks (who's also participating) have already mentioned it, so I figured I'd get in on the action too, and list the program here, for any interested readers (you can also find it online here); you can also click on the presentation titles for the abstracts. 

A Sum Greater Than Its Parts: Multi-Disciplinary Perspectives on Later Human Evolution

Room: Imperial A

Date/time: Saturday Nov. 17, 2012, 1:45-5:15 

Session Abstract:

In anthropology departments across the country- as in the field as a whole- the boundaries between the sub-fields of the discipline are often being drawn more starkly than ever. This reflects the ongoing debates about scientific vs. humanistic anthropologies as well as the increasing specialization of knowledge required for successful scholarship. And yet, even in the face of the increasing fractionation of our field, certain avenues of anthropological inquiry are actually becoming more multi-disciplinary in nature. A particularly noteworthy example is found in the study of later human evolution. Researchers from an array of fields—paleoanthropology, archaeology, behavioral and evolutionary ecology, genetics, linguistics, cognitive psychology, and primatology—produce independent and overlapping datasets that address the behavioral and biological evolution of our species. It is only by embracing the contribution of scholars across sub-field- and disciplinary- boundaries that the complexity of recent human evolution can be understood.

 

The purpose of this session is to bring together scholars who approach the study of human evolution from different perspectives, both to demonstrate the unique contributions being made by the disciplines represented, and as a means of highlighting the critical importance of collaborative work to a more deeply nuanced understanding of the later evolution of our species.

1:45 PM

Blurred Boundaries and Constructed Niches: Interweaving the Individual, the Group and the Community In Human Evolution

Agustin Fuentes (University of Notre Dame)

2:00 PM

Why Humans (especially simple foragers) Are So Egalitarian

Frank W Marlowe (University of Cambridge) 

2:15 PM

Territoriality, Tolerance and Testosterone: Hormonal Correlates of Male Chimpanzee Behavior and Their Implications for Human Evolution

Marissa Sobolewski (University of Michigan), John Mitani (University of Michigan) and Janine Brown (Smithsonian Institution) 

2:30 PM

A Primate Perspective On the Evolution of Human Life History

Tanya M Smith (Harvard University), Andrew Bernard (Freelance Nature Photographer), Ronan Donovan (Freelance Nature Photographer), Zarin Machanda (Harvard University), Amanda Papakyrikos (Wellesley College) and Richard Wrangham (Harvard University) 

2:45 PM

Childhood, Play and the Evolution of Cultural Capacity In Neanderthals and Early Modern Humans

April Nowell (University of Victoria and University of Victoria) 

3:00 PM

Discussant

Milford H Wolpoff (University of Michigan) 

3:15 PM - Break

3:30 PM

Fuzzy Boundaries: The Importance of High-Resolution Datasets for Studying Behavioral Change Across Transitional Periods In the Later Pleistocene

Jamie L Clark (University of Alaska Fairbanks)

3:45 PM

Cultural Diversity and Rates of Change In Structured Populations: A Review of Some Recent Models and Their Implications for Understanding the Appearance of Behavioral Modernity During the Paleolithic

Luke Premo (Washington State University and Max Planck Institute for Evolutionary Anthropology) 

4:00 PM

Neandertal Genetics: Drawing a New Boundary for Humanity

John Hawks (University of Wisconsin-Madison) 

4:15 PM

If Not the Neandertals: Reproductive Barriers and Speciation In the Pleistocene

Adam P Van Arsdale (Wellesley College) 

4:30 PM

Working Hard or Hardly Working? A Preliminary Study of the Metabolic Costs of Stone Knapping

Eric Martin Heffter (University of Arizona), David Raichlen (Universtiy of Arizona and University of Arizona) and Steven Kuhn (University of Arizona) 

4:45 PM

Language, Myth and the Symbolic Mind: Cultural Anthropology Enters the Middle Stone Age

Alan J Barnard (University of Edinburgh and University of Edinburgh) 

5:00 PM

Discussant

Julien Riel-Salvatore (University of Colorado-Denver) 

Taking peddlers of 'paleo-porn' to task

The New Scientist has a short interview with April Nowell ('Palaeo-porn': we've got it all wrong) about an upcoming paper of hers (with M. Chang) in which they expose (eh!) the pernicious tendency to view Venus figurines as having overt sexual meaning. This is timely as my students and I were discussing Venus figurines in my Research Design grad class last week! Among other things, I really dug how she takes to task reputedly serious outfits for promoting this kind of facile interpretation of these objects:

When respected journals - Nature for example - use terms such as "Prehistoric pin-up" and "35,000-year-old sex object", and a German museum proclaims that a figurine is either an "earth mother or pin-up girl" (as if no other roles for women could have existed in prehistory), they carry weight and authority. This allows journalists and researchers, evolutionary psychologists in particular, to legitimise and naturalise contemporary western values and behaviours by tracing them back to the "mist of prehistory".

I like how EP is singled out here - not all of it is bad, of course, but that which is most egregious in transposing current 'commonsense' realities onto the past does drinks deeply from the well of these kinds of unsupported assertions, drawing on the apparent reputability of the sources in which they were published to bolster the credibility of their own conclusions. That's not to say that sexuality wasn't one of the dimensions of at least some Venus figurines, but Nowell's perspective certainly goes a long way to show that assuming that this was the single or most important motivation behind their manufacture in many cases probably says more about prehistorians than it does about prehistory itself.

I also really cannot agree enough with her observation that assuming that all figurines look like the ones from Willendorf or Dolni Vestonice biases our understanding of how variable this class of objects truly is. If we don't acknowledge this variability and the fact that it is a defining feature of figurine-making in the Upper Paleolithic, we're doing our interpretations a major disservice. By extension, we're also doing a major disservice to the interested public who often has a strong interest in the past of our species. In fact, assumptions about the homogeneity of various forms of behavior in the Upper Paleolithic (e.g., cave art, burials) has really been an impediment to getting a realistic understanding of what life between 45-10,000 BP must have been like.

Read the whole thing, it's well worth your time, and make sure you also check out the gallery that accompanies the piece - there's even more info in there.

Picking a journal to publish in as a student

Mike Smith has a post on picking what kind of journal to publish in (mostly) as a graduate student. Rightly, he points to the need of striking the right balance between the prestige/name recognition of the journal and the desire to have the publication come out in a timely manner. As he says "They need quick publications, which would favor a lower-ranking journal. But a paper in a top journal looks awfully good on your CV." He then provides a few personal rules of thumb to help resolve this tension.

I'm in the process of writing another post about tips for publishing as a graduate student that builds on another one of Smith's recent posts, and one of the points I'm making is this: As unbelievable as it probably feels to graduate students, they actually have more time than faculty members, given that the impacts of not publishing are somewhat less negative to their immediate success - though of course publishing during your grad years is nothing but a net positive. In any case, this relative luxury of time means that students can (and should) risk 'shooting for the stars' and submit to prestigious venues, even if they have long turnaround times and/or high rejection rates - Current Anthropology would appear to be a prime example here. Now, this piece of advice comes with one fairly major caveat: you have to start publishing early as a graduate student; if you're staring graduation in the face or are at an advanced stage in the PhD and you need publications to be competitive on the job market, then this advice is null and void. But assuming you're at the end of your MA or first year or two of your PhD, the gamble can pay off big. And if it gets turned down, then you still have time to turn the paper around and resubmit somewhere else, now with the benefit of some reviewers' comments.

PS: I realize this is kind of a weird 'getting back to blogging' post, but bear with me... life has been hectic these past several months.

A Very Neanderthal Easter

The thing I love the most about Easter? Chocolate. The thing I love the most about paleoanthropology? Neanderthals. So this past weekend, I decided to combine the two!

From left to right: Chatelperronian ornament, déjeté sidescrcaper, convergent sidescraper (or is it a Mousterian point? no choco-cave bear around to test it), and Levallois point (milk chocolate); center: Neanderthal (white chocolate). Thought about putting in a drop of milk chocolate to give it brown eyes, but figured it might be overkill...

About those Neanderthal eagle talon ornaments

The recent paper by Morin and Laroulandie (2012) in PLoS ONE has been creating a bit of a buzz, suggesting as it does 'non-nutritional' and possibly symbolic use of eagle talons at two Mousterian sites in France. The authors rightly emphasize that the discovery of several eagle talons bearing cut marks from La Ferrassie and Les Fieux articulates quite well with the evidence from Fumane that Neanderthals purposefully harvested visually striking feathers from a variety of bird species, especially raptors. Hawks underscores their observation that this behavior at La Ferrassie likely goes back almost to 100kya, pushing back the age for potentially symbolic use of bird parts by Neanderthals considerably. In my mind, the study also shows how productive it can be to take a new look at old collections.

While I think the paper reports some very interesting observations and that it makes a solid case overall, I'm left wondering about two things:

1) How were these things used as ornaments? They're not pierced, nor do they display no obvious wear traces from having been worn suspended on strings or thongs. With purported feathers, it's one thing. But these things puzzle me a bit from that standpoint, since even the shells found in Aterian and other MSA sites show some kind of wear from having been strung and worn. 

2) I would have loved to see better shots of the cut marks. By this, I mean microscopic shots of the internal morphology of some of these marks themselves to show unambiguously that they were made by stone tools? Don't get me wrong, they certainly look like cutmarks, at least superficially, and their standardized placement on multiple specimens strongly supports the authors' claim. But as the controversy over the Dikika cutmarks has shown all too well, multiple factors can result in marks that can look like those produced by stone tools, so why not rule it out with some good photographs in this case?

Be it as it may, these new data build on the growing corpus of evidence for the use of things like feathers, ochre, manganese and shells as ornaments by Neanderthals well before the arrival of modern humans on the scene. All in all, it also suggests that different groups of Neanderthals likely used different types of ornaments and coloring materials depending on the ecological setting and available animal and mineral resources.

Reference:

Morin E , Laroulandie V (2012) Presumed Symbolic Use of Diurnal Raptors by Neanderthals. PLoS ONE 7(3): e32856. doi:10.1371/journal.pone.0032856

Shake your (Acheulean) money maker

There was a paper presented by Mimi Lam at the last AAAS meeting in Vancouver and which was covered in LiveScience last week and has bit causing something of a stir (and it spells Acheulean correctly!). While I'm always leery of relying only on press reports to make sense of unpublished papers, its abstract is available online and provides a bit more info. In a nutshell, one the arguments of the paper is that by the Middle Pleistocene, handaxes might have been used as a form of currency. I've talked about handaxes before on this blog, along with some of the debates about what drives their morphology - the focus is often on their alleged symmetry and the fact that this feature might not have been purely functional.

I wasn't at the AAAS meetings, so I didn't hear the paper. All I've read so far are the LiveScience piece, the abstract, and a very thoughtful blog post by Rosemary Joyce in which she rightly points to the at the tangled ball of conceptual yarn that money or currency represents from an anthropological standpoint. Definitely worth a thorough read.

My main concern about the study, however, has to do with the handaxes themselves. There is this notion (often repeated in archaeology textbooks) that they can be very symmetrical, and that the overall degree of symmetry in handaxes increases over time. Frankly,  I don't think we can safely assert this at all. Sure, handaxes can be symmetrical on occasion, no question there. But to my knowledge, this remains a very qualitative impression based on selected samples of handaxes, with selection operating both on the geography and age of the biface samples being observed, as well as on the fact that these samples themselves can be selected for. By this, I mean what gets considered a handaxe/biface and considered in these studies about their symmetry (and what the controls are to evaluate what is 'unnatural' symmetry in various contexts), and how that can vary across analysts and studies.

The main problem with the 'time-vectored increase in handaxe symmetry' as I see it is this: to the best of my knowledge, this hasn't been demonstrated empirically to hold true across all of the Old World. Yes, this seems like a fairly tall order. But this is the scale that is implied by this view. Based on my own biased view and experience with handaxes (and I've looked at a few), the opposite could even be said: there is no fundamental change in the degree of symmetry in handaxe assemblages over time - symmetry is a contingent variable determined by factors like blank size and shape, reduction intensity, use-life, technical skill, and maybe social considerations - the social dimensions being the hardest of all to establish objectively, let along attribute a function to. So, if this idea is not demonstrated, any interpretation of handaxe function based on symmetry is also potentially problematic.

I was talking about this with a colleague on Friday, and it struck us that a great dissertation idea would be to actually test this. What you'd need is a large-ish area with many handaxe assemblages recovered using modern excavation techniques for which a baseline chronology is known - some place like the Middle Awash River Basin, maybe. Then, you explicitly define what gets considered a handaxe, and you apply it to all these assemblages (e.g., at minimum, any piece with removals from both surfaces - this is obviously a minimalist definition, but it's given here as an example). Then, you define a way to measure symmetry and establish a baseline for what is considered 'symmetrical' or whether you're looking at symmetry as a continuous variable (ideally, you do both in order to fend off eventual critiques). Then, you get a sense of raw material constraints, site function and reduction intensity for each assemblage, in order to see whether or not any of these is a recurrent conditioner of handaxe morphology, and to factor them out if they do. In particular, you need some controls such as an evaluation of how inherently 'symmetrical' cobbles or flakes used to make handaxes are at various locales, and whether or not this is correlated to symmetry in various assemblages across the study area. Lastly, you measure symmetry on these handaxe assemblages and then, you look at trends over time. Then, you look at various measures: mean vs. median symmetry, coefficient of variation, spread of values, whether or not certain levels of symmetry are only reached after some point in time; the list goes on and on. The point is, we need to actually demonstrate this at the very least at a regional level before we can even consider taking 'increased handaxe symmetry' as the starting point for any subsequent analysis. So there - if you're a graduate student looking for a project, feel free to take this one. I can all but guarantee you that the resulting papers, whether they demonstrated one or the other conclusion, would become ridiculously highly cited.

I think that what we now know about technology (especially earlier technologies like the the Oldowan) would set the null hypothesis here as being that we shouldn't expect increasing symmetry or standardization over time. In other words, high degrees of symmetry can be present from the beginning of the Acheulean and low symmetry can occur in its latest phases. If you look at the Oldowan, the data clearly indicate that people didn't start by knocking off one flake, then a few thousand years realizing that they could knock off another one, and then another one yet more thousand years later. Quite the opposite, it seems that by the time people start regularly working stone, they get it pretty well: they know how to knock off flakes in succession, they realize that different materials flake better than other, going to some effort to get the better stuff (e.g., Stout et al. 2010). My impression is that the same is likely to be applicable to handaxe technology: once people start flaking cobbles bifacially, they also get it: they realize that you can knock flakes off both surfaces, often using one removal as the starting point for removing another one. And if they understand this, then making an object symmetrical as a result is also implicit - the question becomes why symmetry in certain case and not in others, and why this is the case

So, to go back to Lam's argument, my take on it is not so much that it's wrong (it might end up being right) that I think that we don't have nearly the archaeological resolution we need to objectively discuss the issues she tackles, especially those linked to the question of increasing handaxe symmetry over time, let alone the interpretation of such a pattern. Only when the baseline archaeological work has been conducted, can we really hope to usefully revisit the question.

Some earlier posts on the Acheulean and handaxes:


Plus-sized in the Pleistocene

Two sides to every biface

I say Acheulean, you say Acheulian


References and some suggested reading:

Machin, A. 2009. The role of the individual agent in Acheulean biface variability: A multi-factorial model. Journal of Social Archaeology 9: 35-58.

McPherron, S.P. 2000. Handaxes as a Measure of the Mental Capabilities of Early Hominids. Journal of Archaeological Science 27:655-663.

Monnier, G. 2006. The Lower/Middle Paleolithic Periodization in Western Europe: An Evaluation. Current Anthropology 47:709-744.

Nowell, A., and M.L. Chang. 2009. The Case Against Sexual Selection as an Explanation of Handaxe Morphology. PaleoAnthropology 2009: 77-88.

Stout, D., S. Semaw, M.J. Rogers, and D. Cauche. 2010. Technological variation in the earliest Oldowan from Gona, Afar, Ethiopia. Journal of Human Evolution 58: 474-491.

Bitumen used as hafting material in the Middle Paleolithic of Romania

Cârciumaru and colleagues (2012) report on artifacts from Gura Cheii-Râşnov Cave (Romania), of which a couple bear residues of a blackish material on their surfaces. One comes from the one of the site's Upper Paleolithic levels, while the other comes from its Mousterian deposit which date to between roughly 33.3-28.9 kya (uncalibrated radiocarbon ages).

The reason this is noteworthy is that the authors identify the black residue sticking to the surface of these tools as bitumen (albeit heavily weathered), which they interpret as evidence for those tools having been hafted. This is not a first. The use of bitumen as hafting material in the Middle Paleolithic is known from the Levant, at the site of Umm el Tlel, in levels ranging from 40-70kya in age (Boëda et al. 2008). What is significant, however, is that these new data from Gura Cheii-Râşnov Cave provide the first evidence of using bitumen as a hafting material in the European Middle Paleolithic. From a behavioral standpoint, this joins the evidence for birch pitch tar documented at several Middle Paleolithic sites as old as 125ky bp in Germany (see Pawlik and Thissen 2011) and maybe even older in Italy (Mazza et al. 2006) as evidence for hafting material. This is significant because it reflects the Neanderthal capacity to come up with different solutions for the same problem, namely finding an adhesive to help in crafting composite weapons. In areas where bitumen sources were present and accessible, it makes sense that Middle Paleolithic hominins would not have bothered to go through the time-consuming process of birch pitch tar production detailed by Pawlik and Thissen (2011) when they needed an adhesive and a naturally occurring one was readily available.

Another interesting dimension of the study by Cârciumaru et al. (2012) is that it tells us something about the potential geographical range of the site's occupants. While the precise location where the bitumen was procured remains an open question, the authors indicate that there are deposits of bituminous limestone located about 20km away from the site, and that these deposits were definitely used by the Gravettian occupants of the site who procured high-quality flint from the region where they are found. Alternatively, the also mention a source of bitumen located about 100km to the south of the site. While a local procurement of any material can reasonably be argued to be the null hypothesis of any behavioral interpretation for the Paleolithic, should additional information eventually indicate that the more distant source was used, it would make this the longest distance over which bitumen was procured in the Middle Paleolithic, since the bitumen found at Umm el Tlel came from a source 40km distant from that site (Boëda et al. 2008). Additionally, as mentioned in other posts, Neanderthals are known to have procured lithic material over much longer distances than that, so it wouldn't really be all that surprising if they also collected bitumen from distant sources - especially considering that unlike stone, bitumen doesn't break irreparably and can be re-used and re-shaped over time, which makes its overall utility and use-life much greater than that of stone, thus perhaps justifying traveling long distances to procure it.

References

Boëda, E., Bonilauri, S., Connan, J., Jarvie, D., Mercier, N., Tobey, M., Valladas, H., al Sakhel, H., Muhesen, S. 2008. Middle Palaeolithic bitumen use at Umm el Tlel around 70 000 BP. Antiquity 82: 853-86.

Cârciumaru, M., Ion, R.-M., Niţu, E.-C., Ştefănescu, R. 2012. New evidence of adhesive as hafting material on Middle and Upper Palaeolithic artefacts from Gura Cheii-Râşnov Cave (Romania). Journal of Archaeological Science, doi: 10.1016/j.jas.2012.02.016

Mazza, P. P. A., Martini, F., Sala, B., Magi, M., Colombini, M., P., Giachi, G., Landucci, F., Lemorini, C., Modugno, F., Ribechini, E. 2006. A new Palaeolithic discovery: tar-hafted stone tools in a European Mid-Pleistocene bone-bearing bed. Journal of Archaeological Science 33: 1310-1318.

Pawlik, A., Thissen, J. 2011. Hafted armatures and multi-component tool design at the Micoquian site of Inden-Altdorf, Germany. Journal of Archaeological Science 38:1699-1708.

John Hawks lecture at UCD, March 2: Paleogenomics and the Evolution of Neandertals and Denisovans

Back belatedly, but bearing great news! This coming week, John Hawks will be in Denver. On his blog, he's already mentioned the talk that he's giving at the DMNS, but I want to highlight the fact that he'll also be giving a talk at 2:30PM on Friday March 2 on the UC Denver campus, as part of our Anthropology Colloquium series. The event is open to all and free to attend. Here are the details.

"Paleogenomics and the Evolution of Neandertals and Denisovans"

John Hawks, Ph.D.

Dept. of Anthropology, University of Wisconsin

John Hawks' lab is currently working with genomes of archaic humans to uncover the relationships of these ancient people to recent human populations. Most living people trace a fraction of their ancestry to Neandertals, and a smaller proportion trace their ancestry to a mysterious population called the "Denisovans", represented by a genome from an ancient specimen from the Altai mountains. They are uncovering the interactions among these ancient groups -- when and where did they encounter modern humans and exchange genes with them? They are also investigating the function of those ancient genomes, and what new facts their genes can tell us about Neandertal biology. He will talk about his ongoing work related to pigmentation, immune system, muscle physiology and the brain.

2:30 p.m. Friday, March 2, 2012

North Classroom 1535

UC Denver - Auraria Campus (Downtown)

Light Refreshments will be served

What's new on the Italian Middle Paleolithic?

I'm traveling this week, participating in the Roundtable of the Middle Palaeolithic of Italy hosted by the Center for Ancient Mediterranean and Near Eastern Studies(http://camnes.org), which takes place in Florence this coming Thursday and Friday (Feb. 9-10, 2012). I'm really looking forward to it, and looking at the final program, it sounds like a good range of perspectives and regional records will be discussed, which should make for good discussion. This is important given that an underappreciated dimensions of the Italian MP is how varied it is, which really is not al that surprising when you consider the topographic and geographic variability of the peninsula (see e.g., Milliken 2007 for a summary). If possible, I'll try to live blog some of the conference, and I should mention that the organizers have said that the conference presentations should be streamable in real time... I'll update this post accordingly when I have the final details.

How to feed a pregnant Neanderthal

Shorter can be better: Case in point, Bryan Hockett has a short (five pages) paper in press in Quaternary International entitled "The consequences of Middle Paleolithic diets on pregnant Neanderthal women," and it is a must-read for anyone interested in prehistoric nutrition. In a nutshell, what he does here is consider what the hypothesized Neanderthals caloric requirements proposed by a number of recent studies (e.g., Froehle and Churchill 2009; Snodgrass and Leonard 2009) would have meant for a pregnant Neanderthal. In other words, are these estimates even realistic in concrete terms of the number and kinds of animals eaten?

The short answer is no. First, from a strictly caloric standpoint, the amount of food suggested by these estimates is huge, especially for a hunter-gatherer: "from the perspective of a modern fast food diet, a pregnant Neanderthal women would need to eat 10 large burgers per day (or three in the morning, three at mid-day, and four in the evening), or 17 orders of chicken nuggets per day (or five orders in the morning, six at mid-day, and another six in the evening" (Hockett 2012 2012: 2).

Second, and most importantly, the high amounts of meat suggested by the estimates would likely have been lethal for pregnant Neanderthal women. A nutritional ecology perspective emphasizes that humans need more than just calories to survive, especially on range of micronutrients (Hockett and Haws 2003, 2005). Here, using this approach, Hockett shows that the amount of meat currently generally assumed to have been eaten by Neanderthals would have yielded toxic amounts of protein (relative to fat), an unhealthy overconsumption of some mirconutrients (e.g., zinc, potassium - potentially damaging to internal organs), and a severe underconsumption of others (e.g., carbs, folate, calcium). In short, subsisting on a heavily meat-dominated diet given the energy requirements estimated in other published studies would have been impossible. This is all the more dramatic given that he emphasizes that terrestrial herbivores generally yield comparable ranges of essential nutrients. This means that no matter what land mammals they would have hunted, Neanderthals would still have not been able to get the micronutrients to stay alive, especially with the metabolic needs of a pregnant Neanderthal.

This ties in with recent literature that I have discussed on this blog that shows that Neanderthals routinely consumed other kinds of foods than terrestrial mammals, including plants, shellfish and sea mammals, all of which are rich in various essential nutrients often not found in terrestrial mammals. This paper goes a long way to show that hypothetical reconstructions of past diets need to be confronted both with their overall nutritional implications and with archaeological data, the latter of which clearly shows that Neanderthals readily exploited other resources where they were available. As Hockett emphasizes in his conclusion, this is not to say that Neanderthals and modern humans necessarily had comparably broad diets, or that the Neanderthal diet must have necessarily been 'modern' (think about it: is there anything inherently modern about a grizzly bear's diet, even though it sustains it and draws on many resources?). However, it does force people to start grappling with the question of how realistic some recent purported estimates of Neanderthal dietary needs and strategies actually are.

References  

Froehle, A., & Churchill, S., 2009. Energetic competition between Neandertals and anatomicallymodern humans.PaleoAnthropology 2009, 96-116.

Hockett, B. (2011). The consequences of Middle Paleolithic diets on pregnant Neanderthal women Quaternary International DOI: 10.1016/j.quaint.2011.07.002

Hockett, B., & Haws, J. (2003). Nutritional ecology and diachronic trends in Paleolithic diet and health Evolutionary Anthropology: Issues, News, and Reviews, 12 (5), 211-216 DOI: 10.1002/evan.10116


Hockett, B., & Haws, J. (2005). Nutritional ecology and the human demography of Neandertal extinction Quaternary International, 137 (1), 21-34 DOI: 10.1016/j.quaint.2004.11.017


Snodgrass, J., & Leonard, W., 2009. Neandertal energetics revisited: insights into populationdynamics and life history evolution. PaleoAnthropology 2009, 220-237.

Videos as visual aids in presenting experimental archaeology

For reasons that should become clear fairly soon, I've had experimental archaeology videos on my mind lately. In many cases, actually seeing segments of an experimental study play out can convey so much more of the experience itself than summary tables and graphs, which really take the human element out and often don't do justice to some of the phenomena observed as they unfold.

I saw a couple of good example of this last semester, during the student final project presentations in my Lithic Analysis seminar. In part because UC Denver doesn't have a lot of collections available for students to analyze and in part because of my hyping the approach, there was a groundswell of interest in experimental archaeology projects. Two of those resulted in presentations that used video to drive home key observations: The first was a really stark contrast between how groups of male and female knappers communicated during communal knapping sessions. In that one instance, the ladies talked quite a bit, while the men hardly spoke to one another. It's one thing to describe this, but showing the two videos back-to-back really underscored the deafening silence of the guy group - almost everyone in the class remarked upon it.

The other presentation, by one of our grad students, incorporated video of chert and flint nodules being exposed to heat in a replicated prehistoric kiln to study the mechanism of pot lid fractures. The study ended up yielding little usable data because the high heat of the kiln simply cause the nodules to shatter almost on exposure. Again, however, it was one thing to say this in the presentation, and quite another to actually show footage of the nodules literally exploding (complete with the camera holder ducking out of the way in one instance) to highlight just how dramatic the process actually was. It also quite strikingly drove home the point that kilns may not have been the best manner to heat-treat rock in the past!

Especially given how affordable and increasingly user-friendly movie-making software and equipment is becoming, I really can't imagine why an experimental archaeologist would not film given experiments. Even more, after these presentations, I can't imagine some of these videos not being incorporated in professional presentations of these studies, even though I have to say that I haven't seen much of them at, say, the Paleos or those sessions of the SAAs I usually attend.

Is Academia.edu decreasing scholarly communication?

I love Academia.edu - I think it's a fantastic way for papers to reach the broadest possible audience, and it's made me aware of many studies I wouldn't have otherwise heard of. While I'm not necessarily the best Academia citizen myself (I really should start following some people), it's really been a tremendous help in tracking down some papers published in obscure sources that might have otherwise taken me an eternity - well, a few days/weeks, which might as well be an eternity in this internet era - to get my little paws on otherwise.

That said, the other day, I was reorganizing one of my filing cabinets and came to my offprint section. It was great to look at these things again, and seeing some of the personal notes written to me by the authors reminded me of how I first got in touch with some of them, in some cases even before pdfs had become the de facto offprint. What I thought was cool about it was that getting these documents required some kind of direct interaction with the author(s), which helped broaden the range of scholars who would have at least a faint idea of who I was. In some cases, these first contacts laid the groundwork for lasting friendships and even eventual collaborations. The personal nature of these contacts also was part of e-mailing folks for pdfs, once these had become well-established enough, in that you'd start a conversation.

But now, with Academia.edu, sometimes I wonder if the opportunity of these contacts has been lost (or at least decreased). If so, it would mean that something that was instrumental for my personal development as a scholar would be lost to people starting out now. I mean, sure, you can see who accesses certain papers, but that hardly counts as a meaningful interaction, no? Even if you do look at who downloaded a file, it's not like most people will remember this for very long, so that even if you do run into the downloader at some point down the line, the relationship will have to begin from scratch. Unless of course, the content of your paper has pleased or irked them enough to e-mail you as a result...

Quote of the day: Matt Cartmill on evolutionary laws

From the inimitable Matt Cartmill:

"The trick in discovering evolutionary laws is the same as it is in discovering laws of physics or chemistry-namely, finding the right level of generalization to make prediction possible. We do not try to find a law that says when and where explosions will occur. We content ourselves with saying that certain sorts of compounds are explosive under the right conditions, and we predict that explosions will occur whenever those conditions are realized."

Paleoanthropology: Science or Mythical Charter? (2002: 193)