DNA links Native Americans to China
2013-01-23 16:32
Washington - Present-day Asians and Native Americans are
descended from a group of people who were already in China 40 000 years ago,
according to an analysis of fossil DNA published this week.
The genetic analysis showed that the early modern humans
in Beijing had already diverged genetically from the ancestors of modern-day
Europeans.
The researchers took nuclear and mitochondrial DNA from a
leg bone found in the Tianyuan Cave in China in 2003.
Using this, they reconstructed the genetic profile of the
leg's owner, a person who lived at a very interesting time in the history of
modern humans, the researchers said in a statement on Monday.
"This individual lived during an important
evolutionary transition when early modern humans, who shared certain features
with earlier forms such as Neanderthals, were replacing Neanderthals and
Denisovans, who later became extinct," said lead author Svante Paabo, of
the Max Planck Institute for Evolutionary Anthropology.
The genetic analysis from the ancient bone showed
similarities to genetic profiles from modern-day Asians and Native Americans,
the researchers explained.
But the analysis showed that the early modern human near
Beijing had already diverged, genetically, from the ancestors of modern
Europeans.
In addition, the proportion of Neanderthal and
Denisovan-DNA was no higher than that of modern-day humans in the region.
Scientists had previously found fossils of people from
Eurasia 40 000 to 50 000 years ago who looked like modern-day humans.
But the researchers emphasised that the genetic
relationships between these early modern humans and today's people had not yet
been fleshed out.
"More analyses of additional early modern humans
across Eurasia will further refine our understanding of when and how modern
humans spread across Europe and Asia," Paabo said.
