Unlocking the Past on the “Bases” of Ancient DNA

Fossils of archaic hominins hold more secrets to the history of human evolution than we could possibly have imagined. The finding that DNA can still persist in some fossil records, and, more importantly, be successfully extracted, amplified, and sequenced, came with a big promise: to help answer long-standing questions about the evolutionary origins of modern humans, their patterns of migration and interactions with their closest relatives—the Neanderthals—with whom we now know they coexisted in Europe over thousands of years. Thanks to many years of research into ancient DNA and important technical advances in high-throughput sequencing that allowed the sequencing of the complete genome of a Neanderthal woman from the Altai Mountains in Siberia (Prüfer et al., 2014), we know now that there’s a little bit of Neanderthal in everyone whose roots are outside Africa. But how do these small portions of archaic DNA affect people today? Further insights into Neanderthal genetic contributions and their relevance were offered by two subsequent studies (Vernot and Akey, 2014; Sankararaman et al., 2014). For instance, some Neanderthal-derived alleles