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August 4, 2005
What Did Our Hominin Relatives Eat?
Two recent articles speak to the diets of hominins other than Homo sapiens. A story in today's Nature discusses new techniques of analyzing teeth. The researchers studied three-dimensional microwear surface texture using "scanning confocal microscopy together with scale-sensitive fractal analysis." That's quite a mouth full. They looked at the teeth of Australopithecus africanus and Paranthropus robustus. The differences in tooth texture led them to believe that "A. africanus ate more tough foods and P. robustus consumed more hard and brittle items, but that both had variable and overlapping diets."
While their diets may have overlapped during much of the year, the authors speculate,
. . . the contrasts in microwear texture variability found here offer new insights. The greater variation in complexity for P. robustus and in anisotropy for A. africanus suggests that these species altered different components of their diet, but that there was probably substantial overlap in the fracture properties of their preferred foods. Thus, the clear differences between A. africanus and P. robustus microwear may relate, in part, to differences in critical dietary resources consumed only periodically during the year.. . . The overlap and variability identified here for Paranthropus and Australopithecus was not apparent from earlier studies. This suggests that early hominin diet differences might relate more to microhabitat, seasonality or fall-back food choice than to oversimplified, dichotomous food preferences. [references omitted]
In other words, the differences were important when preferred food was scarce and they had to eat the hard to chew stuff.
The second study, on Neanderthal diet, was published in the July issue of the Journal of Human Evolution. John Hawks' blog has a good overview and critique of the paper. Based on studies of Nitrogen isotopes found in Neanderthal and Hyena bones the authors speculate,
Among these available prey, Neanderthals consumed much less reindeer and much more rhinoceros and mammoth than hyaenas. The low proportions of mammoth and rhinoceros in the diet of hyaena, a famed scavenger, indicates that available carcasses of these large herbivores were relatively rare in the landscape. Thus, the high proportions of these animals in the diet of Neanderthals indicate that they were obtained through another strategy than simply scavenging.
But as John Hawks says, "there are good reasons not to believe a word of it." You'll need to go to his site to see all the reasons. The reason for not believing it that I, as a nonprofessional, found most convincing is that a diet of freshwater fish gives the same Nitrogen isotope signature as a mammoth diet. Hawks discusses the fish diet as proposed in another article in a more recent post. Relatively small amounts of freshwater fish could provide the same isotope profile as great gobs of mammoth.
From the current data, it seems impossible to know what Neanderthals ate: a little fish or a lot of mammoth.
Paranthropus and Australopithecus diets via Keat's Telescope
Posted by Duane Smith at August 4, 2005 3:06 PM | Read more on Paleoanthropology |
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