How modern are the hobbits' tools?

There is one passage in the Tocheri et al. (2007) paper that hasn't gotten all that much attention in the media frenzy about the fact that this study 'proves' the hobbits were a different species:

"Our analyses support hypotheses that LB1
is descended from a hominin ancestor that
migrated out of Africa before the evolution of
the shared, derived wrist morphology that is
characteristic of modern humans, Neandertals,
and their last common ancestor. The association
of LB1 with direct evidence of stone
flaking technology comparable to that found at
Oldowan or other Lower Paleolithic sites
throughout the Old World provides
additional support for the hypothesis that the
earliest hominins to use and make stone tools
retained primitive hominin wrist morphology.
The structurally modified
wrist of modern humans and Neandertals
probably evolved sometime between 1.8 and
0.8 Ma. These structural modifications
form a morphological complex that may
represent an adaptation for better distribution
of forces radio-ulnarly across the wrist to
facilitate the full commitment to tool-related
manipulative behaviors that arose in the
hominin lineage leading to modern humans
and Neandertals." (Tocheri et al. 2007: 1745; references excised).

In my view, this passage is of capital importance because it narrows the range of interpretation of the stone tool assemblage associated with the H. floresiensis remains. Here's what they look like in the original Morwood et al. (2004) pub:

(From Pharyngula)

To recap, there are those who think that these tools are basically "Upper Paleolithic", which has been taken to mean either that 1) small-brained hominids can manufacture such things (Morwood et al. 2004) or 2) that such tools can only be manufactured by modern humans, which means that LB1 is most likely a microcephalic H. sapiens that lived about 18 kya (Martin et al. 2006). Some scholars (e.g., Brumm et al. 2006) have argued that there are strong continuities between Lower Paleolithic industries found elsewhere on Flores, and recently the 'modern' features of the lithic assemblage associated with LB1 have been downplayed significantly, suggesting it is relatively simple and part of a technological sequence that involved the production of both 'core tools' and flakes (Moore and Brumm 2007).

Personally, I have never been especially convinced by the claims for systematic blade technology associated with LB1. The two 'macroblades' (a, b) and two 'microblades' (e, f) illustrated by Morwood et al. (2004: Fig. 5) aren't very regular (the central dorsal ridges are not straight in any of them) and none of their platforms (from what can be seen) are truly 'lipped', unlike the platforms usually generated by soft-hammer production (which is largely employed in true blade production). Furthermore, the illustrated "burin core" really looks to me like a flake core from which a series of small flakes with subparallel edges were knocked off, not a bladelet core. None of this really conforms to the "narrow blades removed sequentially from blade cores" alluded to by some detractors (in Culotta 2007:741) who considers they can only be produced by H. sapiens (a misleading assertion anyway [Bar-Yosef and Kuhn 1999]). Rather, M. Moore and T. Sutkina , who have studied the tools, argue that they represent fairly "simple stone artifacts" (in Culotta 2007:741), which happen to include a few flakes that are twice as long as they are wide - the traditional, if slightly outdated, definition of a blade.

Also keep in mind this "trade secret" of archaeologists: the pieces selected for illustration in published papers are usually the "best looking" ones. In other words, if people want to show they have blades in their assemblage, they tend to illustrate the best examples, even if they don't necessarily accurately reflect the range of products they're actually dealing with. If they had regular, textbook blades in their assemblage, I'd be very surprised that Morwood et al. (2004) had chosen not to illustrate them instead of the ones presented in Fig. 5.

In any case, this is where the Tocheri et al. (2007) paper comes in: Blade technology and prepared core technology, which Neanderthals and modern humans are known to have been able to produce, requires a substantial degree of skill and manual dexterity. The tools at Liang Bua do not reflect this kind of manual dexterity and indeed appear to be very close to Lower Paleolithic freehand flake production strategies. This is the kind of technology which could be expected to be associated with pre-modern wrist morphology, which Tocheri et al. (2007) make a strong case for. For me, this is an instance of two sets of paleoanthropological evidence potentially coming together rather nicely and coherently to support one another, and it would lend credence to the hypothesis that the wrist morphology of LB1 was typical of the hominins who produced the stone tools found at the site. While this study obviously doesn't resolve the issue of whether LB1 represents a distinct species and while it is possible for modern humans to produce more rudimentary lithics, the various evidential threads do seem to be starting to come together as an integrated whole.

This discussion and the new paper nonetheless raise a few more issues for me: looking at the scans of various kinds of wrist bones presented in the paper, it looks like the LB1 bones are most similar to those of chimps, not those of early Homo or Australopithecus. What gives? Granted, there aren't very many bones of fossil hominins that we can compare the LB1 wrist to, but what might be the implications of this for the taxonomic designation of LB1 and, especially, for the necessary morphological and neurological preconditions for systematic, purposeful tool production?

References:

Bar-Yosef, O., and S. L. Kuhn. 1999. The big deal about blades: laminar technologies and human evolution. American Anthropologist 101:322-338

Brumm, A., F. Aziz, G. D. van den Bergh, M. J. Morwood, M. W. Moore,I. Kurniawan, D. R. Hobbs, and R. Fullagar. 2006. Early stone technology on Flores and its implications for Homo floresiensis. Nature 441:624-628.

Culotta, E. 2007. The Fellowship of the Hobbit. Science 317:740-742.

Martin, R. D., A. M. MacLarnon, J. L. Philips, and W. B. Dobyn. 2006. Flores Hominid: New Species or Microcephalic Dwarf? The Anatomical Record A 288A:1123-1145.

Moore, M., and A. Brumm. 2007. Stone artifacts and hominins in island Southeast Asia: New insights from Flores, eastern Indonesia. Journal of Human Evolution 52:85-102

Morwood, M. J., et al. 2004. Archaeology and age of a new hominin from Flores in eastern Indonesia. Nature 431:1087-1091.

Tocheri, M. W., C. M. Orr, S. G. Larson, T. Sutikna, Jatmiko, E. W. Saptomo, R. Awe Due, T.Djubiantono, M. J. Morwood, W. L. Jungers. 2007. The Primitive Wrist of Homo floresiensis and Its Implications for Hominin Evolution. Science 317:1743-1745.

Of wrists and hobbits

There's a short feature in Nature News that reports the publication of a paper by Matt Tocheri (Smithsonian) and colleagues in tomorrow's issue Science. This is the published version of the paper Tocheri presented at the Paleo meetings this year, in which they presented an analysis of the wrist morphology of LB1 (H. floresiensis), which they show is very different from that of modern humans. If LB1 was microcephalic, this would be somewhat unexpected, so this paper overall lends support to the "hobbit as separate species" camp.

The Nature News feature also includes some comments by Dan Lieberman and Robert Martin about the discovery. Check out also this interview with Tocheri about the paper.

Shell working and behavioral modernity

The most recent Current Anthropology contains a paper by K. Szabó and colleagues (2007) about the behavioral implications of shell working dating back to 28-32 ky bp at Golo Cave, on Gebe Island (E. Indonesia). Here's the abstract:

"The evolution of anatomical and behavioural modernity in Homo sapiens has been one of the key focus areas in both archaeology and palaeoanthropology since their inception. Traditionally, interpretations have drawn mainly on evidence from the many large and well-known sites in Europe, but archaeological research in Africa and the Levant is increasingly altering and elaborating upon our understanding of later human evolution. Despite the presence of a number of important early modern human and other hominin sites in Southeast Asia, evidence from this region has not contributed to the global picture in any significant way. Indeed, the acknowledged simplicity of lithic assemblages has led generations of scholars to assume that Southeast Asia was far from the cutting edge of behavioural evolution. Comparison of sophisticated shell tools fromlevels dated to 32,000–28,000 b.p. in eastern Indonesia with lithic artefacts recovered from the same levels and an assessment of raw material procurement suggest that using lithic technologies as markers of behavioural complexity may be misleading in a Southeast Asian context and, indeed, may be hampering our efforts to assess behavioural complexity in global and comparative frameworks."

The paper contains a very good description of the distinct technological pathways followed by the Golo Cave hominins to fashion implements out of shell and stone. While their discussion is somewhat limited by the small sample sizes with which they had to deal (51 lithic artifacts, 14 shell artifacts), they do make a strong case that the two kinds of materials were worked in different manners. Further, they adequately emphasize that the worked shell material (i.e., the opercula of Turbo marmoratus, a marine snail) was collected through targeted procurement in subtidal or lagoonal waters - not opportunistically as an expedient alternative to stone. And this, they argue, represents evidence of "behavioral modernity" because materials that were not immediately available were not worked in the same way as stone, which was worked at Golo Cave in an essentially expedient manner. That is, material that was more difficult to obtain was worked more carefully than that which was easier to procure.

They present, in my view, a solid discussion about how different this kind of shell working is from that documented in the Mousterian of Grotta dei Moscerini (Italy), where shells appear to have been collected opportunistically and worked in much the same way as stone flakes. That said, I disagree with their implication that the shell working documented at Golo Cave really is evidence of "modern behavior", at least as they seem to be conceiving it. This is a point made well in I. Davidson's comment on the paper: Szabó et al. don't clearly define what they mean by "modern behavior" which makes it difficult to situate their argument in the broader debate about this issue. From the paper, I gather that they see modern human behavior as being qualitatively different from that of non-modern hominins such as, for instance, Neanderthals. This is why they discuss the differences between their case study and the Moscerini shell artifacts. Now, as I've said, there's no question that shell working at Golo and Moscerini are very different in nature. However, the subsequent implication is that this is proof-positive that Neanderthals were not behaviorally modern, at least not in the same way as the Golo Cave foragers.

This is where I disagree with them: their argument basically boils down to claiming the fact that the Golo Cave toolmakers treated hard-to-procure material in a different, more elaborate way than more easily accessible stone is evidence of modernity (and perhaps even of symbolic behavior, though this is simply stated and not discussed in any depth in this paper). In light of this, I just want to point out that there is plenty of evidence that Neanderthals managed (i.e., knapped) different kinds of raw materials in very different manners, even within single assemblages. Talking about what I know best, in the Mousterian (and Uluzzian) of the Salento peninsula, "formal tools" were much more often made on flint, chert and quartzite, which are not available locally (i.e., were most likely procured 100+ km away). Likewise, the whole operational sequence of production is usually not documented in those sites, implying careful management and transport of these prized mineral resources. Locally available limestones, in contrast, were frequently worked, by and large in very expedient manners. A similar, though not identical, situation is documented at other Mousterian sites where long-distance raw material procurement is documented, for instance at Champ Grand, in France (which I discussed previously here), where exotic materials are found mainly as heavily retouched tools that likely doubled as portable cores (Slimak and Giraud 2007).

All in all, Szabó et al.'s study is an interesting presentation of the different technological responses of Pleistocene foragers to different kinds of raw materials. As well, their desire to transcend the essentialism of the usual 'trait list approach' to the definition and archaeological recognition of "behavioral modernity" is laudable and one with which I am in fundamental agreement. However, if their argument for behavioral modernity at Golo Cave is accepted at face value, the implication is that Neanderthals were also behaviorally modern, in at least some (important) respects...

References:

Slimak L., and Y. Giraud. 2007. Circulations sur plusieurs centaines de kilomètres durant le Paléolithique moyen. Contribution à la connaissance des sociétés néandertaliennes. Comptes Rendus Palevol 6:359-368.

Szabó, K. , A. Brumm, and P. Bellwood. 2007. Shell Artefact Production at 32,000–28,000 BP in Island Southeast Asia. Thinking across Media? Current Anthropology 48:701-723.

Pasta Strike!

Italy Urged to go on Pasta Strike!

Hmmm... doubt that'll work, though it is for a good cause. I, for one, abstained from consuming my almost-daily dose of semolina-based ambrosia, if only to show support for The Cause. Frankly, though, I only heard about this today - you'd think they'd have publicized it a bit better.

Latest Four Stone Hearth is up and running

Run, do not walk, over to John Hawks' blog to check out the latest installment of Four Stone Hearth! Once again, there's lots of goodies gathered in there!

Clean-toothed Neanderthals

In case you haven't heard, two Neanderthal molars were recovered at the ca. 68.4 kya Spanish site of Pinilla del Valle, near Madrid. While finding any Neanderthal remains is always good news to me, the spin taken on those two (and, presumably, the reason which such a comparatively small find wound up being news on Reuters and El País) is that they display grooves that have interpreted as evidence for habitual toopicking. Martín Cagliani and John Hawks have already mentioned a 2003 paper by L. Hlusko to make the point that this discovery should come as no surprise since there is suggestive evidence of toothpicking going back to about 1.8 mya (on the Omo L 894-1 RP³ specimen).

I agree with them that the discovery as such should come as no surprise. However, I'd alo like to point out another CA paper on the topic of toothpicking,- this one by Agger et al. (2004), which has a set of altogether different implications. Agger et al. (2004:403)) argue "that toothpicking behavior may represent indirect evidence for the evolution of the biological capacity for language." Briefly, this is due to the presence of cranial nerve V, the largest branch of which controls (among other things) lingual movement and makes the teeth and gums extremely sensitive to various irritants. And toothpicking is one way to remove small irritants lodged between the teeth and/or in the gum. They conclude that:

"As anyone who has had small pieces of food caught between his or her teeth or has developed a tooth chip is aware, such occurrences cause a sensation out of proportion to the size of the food matter or tooth defect. This exquisitely sensitive neural pathway for conveying proprioceptive information to higher brain centers can only be routed via a developed and functioning cranial nerve V. As a result, oral dental sensations promote the obligatory postprandial toothpick, at least in modern times and plausibly in early hominids. The proprioceptive information is not only protective but critical feedback for the tongue posturing necessary for speech.

Thus it appears that both a highly developed afferent cranial nerve V (trigeminal nerve) and VIII (auditory nerve) are needed for input to the Broadman's area along the perisylvian fissure of the human brain, the region of the brain that is critical for the formulation of speech. We hypothesize that the ability to sense and remove food particles between teeth occurred approximately 2 million years ago as a result of selective pressures driving the evolution of complex vocalization of the hominid frontal-parietal lobe." (Agger et al. 2004: 403).

So, if Agger et al. are correct, the Pinilla del Valle discovery might imply not only that Neanderthals could and did practice some form of dental hygiene, but also - and perhaps mostly importantly - that they had the capacity for speech, as is also suggested by the presence of an essentially modern hyoid bone in the Neanderthal larynx (Arensburg et al. 1989).

References

Agger, W. A., T. L. McAndrews, and J. A. Hlaudy. 2004. On Toothpicking in Early Hominids. Current Anthropology 45:403-404.

Arensburg, B., A. M. Tillier, B. Vandermeersch, H. Duday, L. A. Schepartz, and Y. Rak. 1989. A Middle Palaeolithic Human Hyoid Bone". Nature (338): 758-760.

Hlusko, L. J. 2003. The Oldest Hominid Habit? Experimental Evidence for Toothpicking with Grass Stalks. Current Anthropology 44: 738-741.