Friday, September 21, 2007

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?


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.

1 comment:

Anonymous said...

I love these types of arguments but frankly I wish there were more specimens available to address these ongoing debates. It’s getting tiresome hearing this wrangling about this single find. The discovery of Homo floresiensis could be one of the great stories in human evolution and hopefully we’ll know more once the original research team gets back to the caves in Flores and to the other islands. Hard to believe, but their work was halted by the Indonesian government at one point further adding fuel to this mess.

Of course, I have a vested interest in hoping this story has some validity to it, having written a fictional adventure novel called Flores Girl on the recent find. If you are interested, there is more on this ongoing controversy about Homo floresiensis at

Erik John Bertel