Meaty Discovery: Neandertal Bone Chemistry Provides Food For Thought

An international team of scientists firmly concludes the latter in a report to be published June 20 in the prestigious journal, Proceedings of the National Academy of Sciences. The article will be posted on the PNAS Web site at http://www.pnas.org on June 13.

Through bone-chemistry analyses, the team determined the Neandertals must have feasted on meat. The Neandertal diet - which may have included mammoths - was similar to other top-level carnivores from the time period, such as wolves and lions, the researchers said.

"This research puts to end the argument about whether the Neandertals were primarily scavengers," said team member Erik Trinkaus, Ph.D., an anthropologist at Washington University in St. Louis. "With a diet dominated by animal protein, the Neandertals must have been effective predators. This implies a much higher degree of social organization and behavioral complexity than is frequently attributed to the Neandertals."

Michael P. Richards, Ph.D., of the University of Oxford, U.K., and of Simon Fraser University, Canada, led the team, which included Trinkaus; Fred Smith, chairman of the Department of Anthropology at Northern Illinois University; and other researchers at Oxford, the Croatian Academy of Sciences and Arts and the University of Zagreb, Croatia.

The scientists analyzed a jawbone and skull bone from two Neandertals recently dated to about 28,000 years old. The fossils were recovered at the Vindija cave site, located about 34 miles north of the Croatian capital of Zagreb. Researchers then compared the bone composition with other central European animals of the same time period, including wolves, wild cattle, mammoths, arctic fox and cave bear.

Smith noted: "For several decades, archaeologists have debated the importance of meat in the Neandertal diet, but this question never has been answered unequivocally. Our findings provide conclusive proof that European Neandertals were top-level carnivores who lived on a diet of mainly hunted animal meat."

By itself, archaeological evidence - in the form of remains of animal bones and stone tools that were used for hunting - provides only a glimpse of Neandertal diets. Some scientists have argued that there was little evidence that the Neandertals were accomplished hunters.

"We've known meat clearly was a part of the diet of the Neandertals, but it was impossible, from the archaeological evidence alone, to see the actual proportion of meat in their diets," Smith said. "Stable-isotope analysis yields a direct measure of human diet, since our bones record the isotope signatures of the foods we ate in our lifetimes. By measuring these isotope signatures in fossil bones, we can reconstruct aspects of the diets of humans and animals from the past."

The new evidence suggests the European Neandertals may have eaten almost exclusively meat. "It's still hard for us to know for certain, but it doesn't appear that they were getting much in the way of nutrients from something other than meat," Smith said.

Trinkaus added: "The isotope data - combined with archaeological analysis of faunal remains and tools found with the Neandertal fossils - indicate that hunting of mammals was a major element of their subsistence. Conversely, plant foods are almost invisible in the archeological record, making it impossible to estimate accurately their dietary importance."

The new findings, along with data from older samples of Neandertal fossils in France and Belgium, show a pattern of European Neandertal adaptation as carnivores, the researchers said.

The Neandertals commonly are portrayed as prehistoric humans of limited capabilities who were rapidly replaced and driven to extinction by superior early modern humans, once the latter appeared in Europe. The team's findings not only offer new information about the European Neandertals' diet, but also about their social behavior, including manipulation of their environment.

"There's no reason to believe Neandertals were any less efficient exploiters of the environment than modern humans," Smith said.

In a study last fall involving Vindija fossils, members of the same research team documented through radiocarbon dating that the Neandertals roamed central Europe as recently as 28,000 years ago, representing the latest date ever recorded for Neandertal fossils. These previous findings - combined with recent evidence of late Neandertal survival in Iberia and of Neandertal-modern human interbreeding in Portugal, the latter of which also was published in PNAS - indicate that the Neandertals were able to coexist and interact successfully with early modern humans spreading across Europe at the time.

"The new bone-chemistry data combined with evidence of sustained Neandertal coexistence and interbreeding with early modern humans offer a positive picture of the Neandertals and may make it easier for some to accept the possibility that the Neandertals were among the ancestors of early modern humans," said Trinkaus, professor of anthropology in Arts and Sciences.