"This is an extinct genome sequence of unprecedented accuracy", says Matthias Meyer, the lead author of the study. "For most of the genome we can even determine the differences between the two sets of chromosomes that the Denisovan girl inherited from her mother and father". From this the researchers can tell that genetic variation of the Denisovans was lower than in present-day humans. This is likely due to that an initially small Denisovan population that grew quickly while spreading over a wide geographic range. "If future research of the Neandertal genome shows that their population size changed over time in similar ways, it may well be that a single population expanding out of Africa gave rise to both the Denisovans and the Neandertals", says Svante Pbo, who led the study.
The researchers furthermore generated a list of about 100,000 recent changes in the human genome that occurred after the split from the Denisovans. Some of these changes affect genes that are associated with brain function and nervous system development. Others possibly affect the skin, the eye and dental morphology. "This research will help determining how it was that modern human populations came to expand dramatically in size as well as cultural complexity while archaic humans eventually dwindled in numbers and became physically extinct", says Svante Pbo.
Earlier this year, the Leipzig researchers had already made the entire Denisovan genome sequence available to the broader public by publishing it online.
|Contact: Matthias Meyer|