Scientists have squeezed enough DNA out of a Neandertal fossil to compare it with the only other existing Neandertal DNA sample, as well as with the genetic makeup of people today.
Even with these new data, however, debate continues over the role of Neandertals in the evolution of modern humans.
The two ancient sequences of mitochondrial DNA—inherited from the mother—contain similarities that they do not share with comparable gene sequences in modern humans, report geneticist William Goodwin of the University of Glasgow in Scotland and his coworkers. Further analysis yielded no support for a Neandertal contribution to the modern human mitochondrial DNA pool, the researchers contend.
Proponents of an out-of-Africa theory welcome the new study's conclusions. These scientists argue that modern Homo sapiens originated in Africa around 100,000 years ago and then spread throughout the world, replacing Neandertals in the process.