Ancient neanderthal protein sequenced

March 9, 2005 An international team has extracted and sequenced a protein from a 75,000-year-old Neanderthal fossil in research that demonstrates a new method of comparing genetic relationships between organisms.

"This research opens up the possibility of getting detailed protein information from past human populations, to make inferences about the evolution of human diet and physiology," says Erik Trinkaus of Washington University in St. Louis.

The research was led by Trinkaus and colleagues from Washington University in St. Louis and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

The oldest fossil human protein ever sequenced, the protein came from a Neanderthal discovered in Shanidar Cave, Iraq. Protein sequences can be used in a similar way to DNA to provide information on genetic relationships between extinct and living species.

Since ancient DNA rarely survives, protein sequencing could be used to determine such relationships for very old fossils that no longer contain DNA.

For their study, Trinkaus and colleagues sequenced the bone protein osteocalcin from a Neanderthal and found that it is the same as that in modern humans.

The researchers also found big differences in the sequences of Neanderthals, humans, chimpanzees and orangutans from that of gorillas and most other mammals.

They suggest that this is a dietary response related to an abundance of vitamin C in the diets of herbivores such as gorillas that is absent from the diets of omnivorous primates such as humans and Neanderthals.

The research is reported in the Proceedings of the National Academy of Sciences.