How extinct humans left their mark on us

Most people in the world share 2-4% of DNA with Neanderthals while a few inherited genes from Denisovans, a study confirms.

Denisovan DNA lives on only in Pacific island dwellers, while Neanderthal genes are more widespread, researchers report in the journal Science.
Meanwhile, some parts of our genetic code show little trace of our extinct cousins.
They include hundreds of genes involved in brain development and language.
"These are big, truly interesting regions," said co-researcher Dr Joshua Akey, an expert on human evolutionary genetics from the University of Washington Medicine, US.
"It will be a long, hard slog to fully understand the genetic differences between humans, Denisovans and Neanderthals in these regions and the traits they influence."

Siberia cave

Studies of nuclear DNA (the instructions to build a human) are particularly useful in the case of Denisovans, which are largely missing from the fossil record.
The prehistoric species was discovered less than a decade ago through genetic analysis of a finger bone unearthed in a cave in northern Siberia.=read more =bbc link=http://www.bbc.co.uk/news/science-environment-35835126