 He earned his PhD from Uppsala University in 1986 for research investigating how the E19 protein of adenoviruses modulates the immune system.Pääbo is known as one of the founders of paleogenetics, a discipline that uses the methods of genetics to study early humans and other ancient populations.In 1997, Pääbo and colleagues reported their successful sequencing of Neanderthal mitochondrial DNA (mtDNA), originating from a specimen found in Feldhofer grotto in the Neander valley.