送交者: Latino2 于 2005-5-19, 10:50:43:
最早的欧洲人化石是１００多年前在捷克出土的。但是这些欧洲人生活的年代没有定论。 新的测定方法发现 这些欧洲人生活在３１０００年前。
Oldest Europeans Were Swingers
Human fossil remains that were excavated more than 100 years ago from the Mladec caves in Moravia, Czech Republic, belong to the earliest Europeans, according to a new study. Scientists say the bones, now dated to nearly 31,000 years, could help elucidate the fate of Neandertals and the emergence of modern humans.
The Mladec remains are widely accepted as those of early modern humans. But some of the males show characteristic Neandertal features such as a low forehead and flattening at the back of the skull. This has prompted questions about whether the Mladec humans mixed with the Neandertals at a so-called transitional period or instead represent a new species that replaced the Neandertals. The debate, it seemed, could be settled by determining the age of the Mladec remains through carbon dating. To do this, scientists usually rely on collagen, a carbon-bearing compound found in bones. The compound breaks down over time, however, and several previous efforts to date the Mladec remains using bone samples failed.
Maria Teschler-Nicola, an anthropologist at the Natural History Museum in Vienna, and her colleague Eva Maria Wild, a physicist at the University of Vienna, decided to try the approach on teeth instead. "The idea was that collagen in teeth might be better preserved from degradation and contamination by intact enamel of the crown" or bone surrounding the roots of teeth, says Wild. The amount of radiocarbon in the teeth, estimated using the Vienna Environmental Research Accelerator at the University of Vienna, showed that the fossils were about 31,000 years old, suggesting that early modern humans were in the Mladec region during the transitional period. Since some of the specimens show Neandertal features, Wild says it's possible that modern humans have a Neandertal ancestry or that humans and Neandertals may have interbred. Wild and Teschler-Nicola report their results 19 May in Nature.
"It is very exciting that the Mladec remains have finally been dated," says David Frayer, a paleoanthropologist at the University of Kansas, Lawrence. Adds Milford Wolpoff, a paleoanthropologist at the University of Michigan, Ann Arbor, "This is a really cool study that gives us an idea of what the earliest Europeans looked like."