Scientists Discover 3.8 Million Year-Old Proteins

Newswise — A team of scientists has uncovered protein fragments dating back 3.8 million years—a discovery that will enhance future understanding of ancient organisms, including human ancestors.

The fragments were taken from fossil ostrich eggshells found in Laetoli, Tanzania, where 3.75 million-year-old human ancestor footprints were found in the 1970s.

A separate discovery from the same team yielded ancient proteins from 1.7-million-year-old tooth enamel of extinct mammals—deer, horses, and rhinoceroses—from the Dmanisi site in the former Soviet republic of Georgia, which is the oldest site outside of Africa bearing the remains of human ancestors.

“These findings open up the possibility of recovering remnants of ancient proteins from the earliest human fossils,” says New York University Anthropology Professor Terry Harrison, a co-author of the paper.

The research project, published in the journal eLife, was headed by scientists at the University of York, the University of Copenhagen, and the University of Sheffield.

These discoveries are significantly older than the known age limits for the recovery of ancient DNA from fossils, which can be found back in time only to approximately 700,000 years ago.

In recent decades, the study of ancient DNA recovered from fossils has transformed our understanding of the evolutionary relationships of extinct species, including close relatives of humans, such as the Neanderthals. But ancient proteins offer a resource that can provide a similar wealth of information about the biology of extinct organisms from much older time periods.

“Ancient proteins derived from the enamel of fossil teeth have the potential to yield important clues to the evolutionary relationships, species identity, sex, and migration patterns of early human ancestors,” adds Harrison, who serves as co-director of the paleontological project at Laetoli in northern Tanzania that produced the fossil samples that yielded the oldest proteins.

The research was supported, in part, by the Danish National Research Foundation (DNRF94) and the National Science Foundation (BCS-0524087, BCS-1138073, 547414, BCS-9903434, BCS-0309513, BCS-0216683).

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