Modern humans may have picked up key genes from extinct relatives. For a field that relies on fossils that have lain undisturbed for tens of thousands of years, ancient human genomics is moving at breakneck speed. Barely a year after the publication of the genomes of Neanderthals1 and of an extinct human population from Siberia2, scientists are racing to apply the work to answer questions about human evolution and history that would have been unfathomable just a few years ago. The past months have seen a swathe of discoveries, from details about when Neanderthals and humans interbred, to the important...