john hawks weblog

Reading items on my desktop, I found a rant I had written a while back. I generally don't post rants, but a decent amount of time has passed...

I'm totally irritated this morning because we turned on a cable channel where they were showing a documentary about Neandertals from only a few years ago. It's a clutch of talking heads telling stories about what Neandertal life "must have been like", accompanied by actors dressed in skins and clay brow ridges. The difference between the "modern" and "Neandertal" actors is whether the skins have been stripped of fur. If you've seen any human evolution documentaries in the last decade, you know the genre.

Walking caveman shows are hardly anything new, and I've been in a few that have been pretty good. So why am I particularly irritated?

This particular program was such a waste. The producers assembled a fair group of scientists to comment on the Neandertals and clearly spent a lot of money on the production. But then they encouraged those scientists to go way beyond the science. And the scientists went along for the ride.

Here's a hint: When you're talking about the differences between Neandertal and modern human spiritual beliefs, you've gone beyond the science.

Earlier this week, I saw a link on Twitter from a chemist sick of spending time on interviews with journalists: "Another interview makes the cutting room floor".

Yes I wanted to be interviewed because its been drummed into me over 20 years that the public understanding of science is pathetic and we scientists have to do a better job communicating to the masses etc.. Now if you filter the scientists through journalists does that make us better communicators? I think in the pre blog days that was the only way to go but some scientists are cracking communicators and have huge audiences. Not me. My work has a couple of journals and magazines that would likely cover something I might do. The potential for my work to reach a broader audience by contributing to an interview is the “bait”. We scientists are lured hook, line and sinker every time. Bigger audience, equals more citations, more citations equals success, funding and respect. I should go further and say that we try to highlight the work because our collaborators and co-authors also benefit from the exposure.

His complaint is related to tuberculosis research, not bad caveman outfits. But I thought about his concerns when I was watching the program this morning. So many scientists want to help tell good stories about their research, hoping it will make some difference -- a difference to their profile, a difference to public understanding, a difference to their status in the field. It's a mix of selfish and altruistic motivations, a complicated mix.

We can't tell stories alone. But we need to tell our stories, not the stories that writers feed to us.

Eugene Giles has an article in the new Yearbook of Physical Anthropology that will be of great historical interest to many in the field: "Two faces of Earnest A. Hooton" [1]. Hooton was a central character in physical anthropology, and ultimately his students would come to populate most of the positions in physical anthropology in the United States. It is often said that every student who learns osteology in American schools today is fundamentally taking Hooton's course in the subject. He was born in Wisconsin and received his Ph.D. here at the University of Wisconsin, in classics, after a time in the U.K. as a Rhodes Scholar. In other words, he was scientific royalty. Unlike most, he took that status and became a public intellectual of substantial note, publishing popular articles throughout his lifetime on the topics of evolution, race, and eugenics.

Giles has accumulated a rich record of biographical details about Hooton, who was a complex figure. I might describe him as embodying the apotheosis of racial science -- dividing up human groups by an involved scheme of "major" and "minor" races, he attempted to categorize human variation into types purported to represent historical connections among peoples. It is not enough to say that this was typical of physical anthropology, because up until 1950 or so, this simply was physical anthropology. Hooton's students were the first generation to really take an alternative approach, and most of them did so only after a substantial period working with racial categories in a nineteenth-century framework.

Giles approaches crucial questions: Can a racial scientist be a non-racist? Could one be a eugenicist and yet oppose the doctrine of "race hygiene"? Hooton is such an interesting figure because he, more than anyone, stood at the center of established race science during the 1920's and 1930's.

By 1930, Hooton made it clear he believed something had to be done about what he saw as our increasing lack of biological fitness. “[I]n spite of the infinitesimal quantity of our knowledge [of their genetic bases], we are completely justified in urging that measures be taken to prevent the insane and the mentally defective from reproducing. Segregation and sterilization of the unfit ought to be promoted by scientists and by instructed laymen” (Hooton,1930b:103). But at the same time, he goes on to warn that “we have no data which justify the raising of racial issues as a part of eugenics propaganda. We know nothing at all about inherent superiorities or inferiorities of the several races and the many nationalities. If eugenics is to be made the vehicle of bigoted race prejudice, it must be ditched… To me, eugenics in the United States represents too much ill-considered talk and too little careful scientific research” (Hooton,1930b:103). Those in the eugenics movement in the United States who were in fact displaying “bigoted race prejudice” became role models for German “racial hygienists” before Hitler's ascension in 1933 and admirers afterward, for a while (Kühl,1994).

Giles is in the end a defender of Hooton, in opposition to recent public presentations (in particular the "Understanding Race" project by the American Anthropological Association) which Giles sees as having tarnished Hooton's scientific reputation.

For another view of Hooton, Jon Marks returns to blogging: "A Rootin' Tootin' Blog Post". Marks is writing in partial reaction (or addendum) to Giles, accentuating the negative. Marks acknowledges that Hooton was a complicated character -- speaking out against some of the worst instances of scientific racism, but ultimately rooted himself in a typological scheme of human classification that was losing its value.

Anyway, back to Hooton. His ideas about race, and about human biology generally, certainly weren’t the worst ones around at the time, but that’s faint praise. I think my biggest problem with Hooton, since it’s hard to know exactly what he did believe at any point in time, is that he did not use his position as an authority to confront and repudiate the worst elements of racial science in America. He went after the Germans, which was safe, and although he tried to differentiate his racial science from theirs, he ultimately was not very successful, because his physical anthropology was in fact only subtly different from theirs.

However, Marks adds a number of quotes and historical cases in which Hooton presents a less sympathetic side. It is clear that if words are actions, Hooton's record is complicated.

Hooton's racial typological scheme was just as complicated as his position in the history of science. I'm interested in the theory as well as the social impacts of the theory, and this is a great case in the history of science where social change and changes in scientific theories were linked. Like Ptolemaic epicycles, Hooton's classification was an attempt to shoehorn the growing data on human diversity into a theoretical scheme that was losing its value. His typology was full of dozens of "minor races" as variants of the "major" three. Yet the scheme of clinal variation that would come to dominate in postwar anthropology left much unexplained.

I think the Copernican revolution is in some ways a good analogy -- replacing epicycles with heliocentric orbits was in the long run the correct choice, but circular orbits as predicted by Copernicus did not fit the data as well as the overly complicated Ptolemaic scheme. In astronomy, this problem was solved by Kepler and elliptical orbits. But the transition from the geocentric to heliocentric view wasn't easy, with many heavyweight holdouts for a long time, and hybrid systems like Tycho Brahe's geo-heliocentric model.

In human biology, clines were indeed more correct as a description of the pattern of variation. As Hooton and his contemporaries began to appreciate, typological races would have to be endlessly subdivided to adequately account for variation. Any typological theory is weighed down by this complexity.

But the clinal perspective is not as simple as generally presented -- clines of variation in humans are not random, nor equally distributed, and some human populations really have undergone long periods of very low gene flow from others. The advent of genetics in the 1950s promised to make human classification simple -- as simple as blood type frequencies. In fact over time genetics has reinforced the complexity of our history as a polytypic species.

So Hooton, a representative of the Old Guard as his students began to pursue a new kind of human classification, is tremendously interesting. I recommend Giles' entire article, and will be looking forward to seeing more.

References

This week in Science, Jayne Wilkins and colleagues report on part of the lithic assemblage from Kathu Pan, South Africa, which includes 210 points [1]. The paper reports that these are the earliest known hafted points in the world, predating the previous record by more than 200,000 years.

The minireview of the spear literature:

By ~780 ka, hominins were regularly killing large game, based on evidence of repeated in situ processing of complete carcasses of fallow deer at Gesher Benot Ya’kov in Israel (4). At the English site of Boxgrove, a horse scapula with a semicircular perforation is consistent with spear-aided hunting by ~500 ka (5). Wooden spears dating to ~400 ka have been found in association with butchered horses at Schöningen, Germany (6). Hafted spear tips appear to be common in the MSA and Middle Paleolithic (MP) sites of Europe and Africa after ~300 ka (7–20).

This is a very short paper, and it sets out two problems: demonstrating that the points really are 500,000 years old, and demonstrating that they really were used as spear tips. The first is fairly straightforward as a function of the stratigraphy at the site and some ESR/U-series dating of faunal teeth. Possibly a broader issue is the identification of the assemblage as Fauresmith, which has been poorly defined in the literature and sometimes means different things. It is more or less indicative of assemblages based on large cutting tools (such as handaxes), with an increased fraction of flake core production and some MSA-like elements. Andy Herries published a good review of the Fauresmith issue and its chronology last year [2]. He wrote this with respect to Kathu Pan:

Previous dating of the site was based on elephant fossils that were more evolved than those from Olduvai Bed IV [62]. This simply gave the site an age of 417 ka may lend weight to the Fauresmith at Wonderwerk also being in this time range or at least older than 182 ka as suggested by Chazan and Horwitz [147] unless it occurred for over 200 ka in the region and was being produced contemporarily with the MSA.

Fauresmith at some other sites in southern Africa, including Wonderwerk Cave, is apparently younger, less than 300,000 years ago. The entire range is coincident in time with the Early-Middle Stone Age transition in the Kapthurin Formation sites in Kenya, which makes these "transitional" assemblages really representative of a long-term pattern of variability and change. The marker of MSA industries as opposed to Early Stone Age is the MSA's reliance upon prepared core reduction techniques. Yet, prepared core techniques (like the Levallois technique) appear much, much earlier. One marker of the MSA, as reviewed by Herries [2] (citing McBrearty and others) is the appearance of projectile point technology:

Mcbrearty [22] also suggests that the fundamental change from the ESA to the MSA is the end of LCTs and a shift to projectile point technology. Of course, it should be noted that Acheulian bearing hominins in Europe were utilising an entirely wooden projectile technology for hunting as shown by the occurrence of the Schöningen spears at either ~400 (MIS 11 [157]) or ~310 ka (MIS 9d-e; [168]) but were seemingly still disarticulating their kill with LCTs. Whether a similar wooden projectile technology was being used by hominins in Africa is almost impossible to tell given the almost complete lack of preservation of such organic remains in most MSA sites. The exceptions are two wooden tools from Floor 1 at Kalambo Falls in Zambia [30, 56] and one from Florisbad in South Africa [13]. Other sites where large pieces of wood have been recovered include the Acheulian sites of Amanzi Springs [73] and Gesher Benot Ya'aqov [169]. Despite the discovery of significant amounts of wood from these deposits, no tools have been noted. The Kalambo falls tools are reminiscent in some ways of the European “spears” and are associated with large well-formed cleavers from the Acheulian bearing Floor 2, below the Sangoan. Given their context these wood tools might be older than those from Europe and might point to a wooden projectile point technology in the late Acheulian, complimenting the earlier LCT technology. At most sites, the only clue would be in finding injury patterns on faunal remains indicative of such activities. In a similar vein, the co-occurrence of LCTs and projectile point technology in the Sangoan and Fauresmith may reflect similar activity patterns, or as McBrearty [22] suggests that the mix of technologies may, in fact, represent different hominins using different technologies at the same time in the same regions of Africa.

This brings us to the current paper, which pushes the appearance of projectile points back well before the clear appearance of the MSA. So is the evidence solid?

Triangular stone flakes may look on the surface like spear points, but that doesn't necessarily mean they were used that way. Triangular flakes are useful cutting tools, and actually preferred as cutting tools in some archaeological contexts.

The springbok spear test. Figure S6D from Wilkins et al. 2012

I think the authors did a nice job of finding multiple ways to test the use of these points as spear tips. They examined edge wear to show that on these artifacts it is differentially concentrated near the tip. They shot a bunch of experimentally-produced tips into springbok carcasses, showing the pattern of wear that comes from use on a hafted spear, and this pattern matches the archaeological points. Furthermore, they show that experimental use of the points as cutting tools yields a different wear pattern, as does postdepositional damage to the artifacts. They find that some of the points are modified on the base, suggesting hafting, but do not report any evidence of glue or base wear that would have come from the wooden spear. A clever part of their analysis concerns the symmetry of the points. They expected that as a cutting tools is blunted and resharpened, the shape of the overall tool will become skewed, so smaller points should be less symmetrical. The archaeological points show the opposite pattern, with smaller points just as symmetrical as the large ones. The sizes of the points fall within the range of ethnographic and MSA spear points, not smaller projectiles such as arrows or atlatl darts.

So all in all, these look like good spear tips. This seems like yet another case where a more intensive investigation of the African record has shown that supposedly "advanced" toolmaking techniques were mastered by Middle Pleistocene humans. With some of the other techniques -- such as blade production -- people seem to show an effervescent pattern. A handful of sites show an early occurrence of the technique but no clear tradition carrying the early innovation into later time periods. Maybe hafting is another such case, a relatively complex innovation that was repeatedly reinvented, with people repeatedly falling back to the simpler option (in this case, sharpened wood spears without points).

The archaeological record may be giving us a signal of the importance of communication and knowledge accumulation relative to innovation in our prehistory. But to be clear about this will require a fuller record, with fewer blank spots.

References