Neandertal Hunters

TO RECONSTRUCT what early humans ate, researchers have traditionally studied features on their fossilized teeth and skulls, archaeological remains of food-related activities, and the diets of living humans and apes. Increasingly, however, investigators have been tapping another source of data: the chemical composition of fossil bones. This approach has yielded some especially intriguing findings with regard to the Neandertals.

Michael Richards, now at the University of Bradford in England, and his colleagues recently examined isotopes of carbon (13C) and nitrogen (15N) in 29,000-year-old Neandertal bones from Vindija cave in Croatia. The relative proportions of these isotopes in the protein part of human bone, known as collagen, directly reflect their proportions in the protein of the individual's diet. Thus, by comparing the isotopic "signatures" of the Neandertal bones to those of other animals living in the same environments, the authors were able to determine whether the Neandertals were deriving the bulk of their protein from plants or from animals.

The analyses show that the Vindija Neandertals had 15N levels comparable to those seen in northern carnivores such as foxes and wolves, indicating that they obtained almost all their dietary protein from animal foods. Earlier work hinted that inefficient foraging might have been a factor in the subsequent demise of the Neandertals. But Richards and his collaborators argue that in order to consume as much animal food as they apparently did, the Neandertals had to have been skilled hunters. These findings are part of a growing body of literature that suggests Neandertal subsistence behavior was more complex than previously thought [see "Who Were the Neandertals?" on page 28]. -W.R.L.

NEANDERTAL MEALS consisted mostly of meat (from, for example, reindeer), according to analyses of carbon and nitrogen isotopes in fossilized bone.

lier work hinted that improvements in tool technology around 1.4 million years ago—namely, the advent of the Acheu-lean hand ax—allowed hominids to leave Africa. But new discoveries indicate that H. erectus hit the ground running, so to speak. Rutgers University geochronolo-gist Carl Swisher III and his colleagues have shown that the earliest H. erectus sites outside of Africa, which are in Indonesia and the Republic of Georgia, date to between 1.8 million and 1.7 million years ago. It seems that the first appearance of H. erectus and its initial spread from Africa were almost simultaneous.

The impetus behind this newfound wanderlust again appears to be food. What an animal eats dictates to a large extent how much territory it needs to survive. Carnivorous animals generally require far bigger home ranges than do herbivores of comparable size because they have fewer total calories available to them per unit area.

Large-bodied and increasingly dependent on animal foods, H. erectus most likely needed much more turf than the smaller, more vegetarian australo-pithecines did. Using data on contemporary primates and human hunter-gatherers as a guide, Robertson, Susan C. Antón of Rutgers University and I have estimated that the larger body size of H. erectus, combined with a moderate increase in meat consumption, would have necessitated an eightfold to 10-fold increase in home range size compared with that of the late australopithecines— enough, in fact, to account for the abrupt expansion of the species out of Africa. Exactly how far beyond the continent that shift would have taken H. erectus remains unclear, but migrating animal herds may have helped lead it to these distant lands.

As humans moved into more northern latitudes, they encountered new dietary challenges. The Neandertals, who lived during the last ice ages of Europe, were among the first humans to inhabit arctic environments, and they almost certainly would have needed ample calories to endure under those circumstances. Hints at what their energy requirements might have been come from data on traditional human populations that live in northern settings today. The Siberian reindeer-herding populations known as the Evenki, which I have studied with Peter Katzmarzyk of Queen's University in Ontario and Victoria A. Galloway of the University of Toronto, and the Inuit (Eskimo) populations of the Canadian Arctic have resting metabolic rates that are about 15 percent higher than those of people of similar size living in temperate environments. The energetically expensive activities associated with living in a northern climate ratchet their caloric cost of living up further still. Indeed, whereas a 160-pound American male with a typical urban way of life requires about 2,600 kilocalories a day, a diminutive, 125-pound Evenki man needs more than 3,000 kilocalories a day to sustain himself. Using these modern northern populations as benchmarks, Mark Sorensen of Northwestern University and I have estimated that Neandertals most likely would have required as many as 4,000 kilocalories a day to survive. That they were able to meet these de-

Dmanisi,

Dmanisi,

Bahr el Ghazal,

Hadar, Ethiopia

Olduvai Gorge,Q Tanzania O

Longgupo, China?

Bahr el Ghazal,

Hadar, Ethiopia

Olduvai Gorge,Q Tanzania O

Laetoli, Tanzania

Healthy Weight Loss For Teens

Healthy Weight Loss For Teens

Help your Teen Lose Weight Easily And In A Healthy Way. You Are About to Discover What psychological issues overweight teens are facing and how do you go about parenting an overweight teen without creating more problems?

Get My Free Ebook


Post a comment