The Nobel Prize in Physiology or Medicine for this year was awarded to geneticist and evolutionary anthropologist Svante Pääbo for his groundbreaking research on the DNA of extinct people and human ancestors. His extraordinary findings, which have had a profound effect on our knowledge of human evolution, include the identification of a hitherto unidentified type of human who coexisted with modern humans and Neanderthals tens of thousands of years ago.

Our DNA contain the history of how contemporary humans colonised the world and developed sophisticated cultures replete with art and technology. Although the DNA of current Homo sapiens is largely unique, there are certain major sequences that we have in common with Neanderthals and other ancient hominins. Thus, a key to knowing what makes us who we are can be found in understanding our genetic differences.

However, because genetic material is delicate, the majority of the DNA found in ancient bones is severely damaged, chemically altered, and contaminated. Pääbo created a number of novel procedures during many years of persistent research that allowed for the extraction, duplication, and reading of damaged DNA in order to restore the original genetic material. He created paleogenomics as a new field of study in the process.

Less than ten years after the first human genome was published, Pääbo and his team made a number of important discoveries, including decoding the full Neanderthal genome and identifying a new subgroup of prehistoric humans called the Denisovans, who were a sister group to the Neanderthals. Their research revealed extensive contact between contemporary people and Neanderthals and Denisovans. Some of the ancient gene variations they left us are more prevalent in some contemporary populations. Their presence explains several traits, such as why certain people are better able to fend off specific infections and why some are better suited to high-altitude living.

According to academics at the Karolinska Institute Gunilla Karlsson Hedestam and Anna Wedell, 'Pääbo's discoveries have had a major impact on our understanding of our evolutionary history and they have stimulated study in the area.'