Old bones may show why Neanderthals went extinct


Release at 5 p.m. (2100 GMT)

By Deborah Zabarenko

WASHINGTON, May 21 (Reuters) - Old bones may tell the tale of how short,
stocky, hairy Neanderthals were supplanted in Europe some 30,000 years ago by
thinner, taller, more adaptable modern humans, scientists reported on Monday.

By studying the chemicals that remained in the bones of the earliest modern
humans, scientists discovered that their diet, which included fish and fowl
as well as large mammals, may have given them the edge over the Neanderthals,
who favored an all-big-mammal menu.

Both Neanderthals and humans needed to pack on weight, because Europe was a
much colder place then, with glaciers covering the British Isles from time to
time and Scandinavia periodically under ice, according to Michael Richards, a
researcher at the University of Bradford in Britain.

A specialist in the prehistoric diet, Richards said by telephone that a study
published in the current Proceedings of the National Academy of Sciences
looked at the bone chemistry of Neanderthals and the modern humans that
coexisted and eventually supplanted them.

Previously, scientists had generally looked at old stone tools and animal
bones found near human remains to get an idea of what early modern humans and
their ancestors ate. But Richard said this method could give equivocal or
incomplete results, while bone chemistry provided clearer clues.

"The bones are made up of the foods you eat, so they're a direct measure of
diet," Richards said. And while the ancient bones might degrade in some
cases, scientific analysis showed that the bones used in this study did not,
he said.

SLIM PICKINGS

The pickings were rather slim: scientists worked with data from the bones of
five Neanderthals and nine skeletons of early modern humans, all from a
period some 20,000 to 30,000 years ago.

This was near the end of the Neanderthals' time in Europe, and the beginning
of the modern humans' time, with an overlap of about 10,000 years. Before
this, Neanderthals had lived in this area starting about 120,000 years ago,
Richards said.

The key to the modern humans' survival was a more diverse diet, which gave
them more choices in lean periods.

Neanderthals spent most of their lives hunting and eating large mammals, such
as red deer, reindeer and sometimes mammoth, Richards said. This diet kept
their heavy muscles going and enabled them to survive.

But when early modern humans moved into Europe, probably from Africa, they
brought an appetite for the same large herbivores that the Neanderthals
wanted, putting pressure on supply.

However, while Neanderthals only wanted the land mammals, the modern humans
also caught fish and wild birds to supplement their diet and this
adaptability tided them over when times were lean, Richards said.

"My take on this is this is why Neanderthals were extinct while modern humans
were much more successful," he said, but he noted that even some of the other
authors of the study disagreed with this theory, with some saying that
interbreeding or other factors may account for the Neanderthals'
disappearance.

Vegetables and fruits played little role in the diets of Neanderthals and
early modern humans, he said.

"They were eating some (vegetables and fruits) but it was not enough to show
up in their bone chemistry," Richards said.