The complete genome sequences from the Neanderthals and groups related to them make it possible to identify all positions in the genome where these archaic humans are similar to chimpanzees and other apes, while all present-day humans are identical to each other but different from Neanderthals. Dr.  Pääbo is intersecting these data with a formalized approach to find regions affected by positive selection in modern humans, with gene expression data from the brains of humans and other primates, and with data on primate conservation in order to identify changes in coding as well as non-coding DNA sequences that are likely to have significant functional consequences.

Dr. Pääbo will then test the ancestral and derived versions of these genes in cells, in tissue culture, in iPS cells, or in mice, in order to better understand their function.