Svante Pääbo: Your Internal Neanderthal

Over 30, we have worked methods to study the tiny amounts of DNA that can sometimes be found in ancient bone from extinct organisms. In particular, we have focused on reconstructing DNA sequences from Neandertals, the closest extinct relative of present-day humans and on Denisovans, a hitherto unknown group of Asian hominins distantly related to Neandertals.

Analyses of these genomes show that Neandertals contributed about 2.0% of the genomes of people today living outside Africa while Denisovans contributed about 4.8% of the genomes of people living in Oceania as well as small amounts to people elsewhere in Asia. Together, these finding suggest a ‘leaky replacement’ scenario of human origins in which anatomically modern humans emerged out of Africa and received some degree of gene flow from archaic human populations. Work from several laboratories has shown that these genetic contributions have consequences today for the immune system, for lipid metabolism, for adaptation to life at high altitudes in the Himalayas, and for susceptibility for diseases such as diabetes.

The Neandertal and Denisova genomes also allow the identification of novel genomic features that appeared in modern humans since their divergence from a common ancestor with their closest extinct relatives. We speculate that among these features may be some that allowed modern humans to develop complex culture, technology and art.

Svante Pääbo has pioneered the study of ancient DNA, allowing the genomes of extinct creatures such as mammoths, ground sloths and Neandertals to be determined. His research group sequenced the Neanderthal genome and discovered Denisovans, a previously unknown Asian hominin related to Neanderthals. His work has demonstrated that these now extinct groups have contributed to the genes of present-day people and has opened up new ways to study human origins and genes that may underlie aspects of traits specific to humans.