ISTOCK, MARTINWIMMERA newly discovered molecule called Gc-CS—derived from Neu5Gc, a glycan made by chimpanzees and ancient humans—can shed light on our human ancestors. In a proof-of-concept study, scientists were able to detect this molecule in various samples, including human serum and 4-million-year-old bovid bones—a family of animals that include cattle and bison, according to a paper published yesterday (September 11) in PNAS.
“Once we’ve refined our technique to the point that we need smaller sample amounts and are able to obtain ancient hominin fossils from Africa, we may eventually be able to classify them into two groups—those that have Gc-CS and those that do not,” says senior author Ajit Varki of the University of California San Diego School of Medicine in a news release. “Those that lack the molecule would mostly likely belong to the lineage that led to modern humans.”
Ancient human ancestors were able to synthesize Neu5Gc for millions of years, but then lost this ability following a mutation in the gene for the synthesizing enzyme, write the authors in their report. Scientists could detect small amounts of the molecule’s metabolite in modern humans because ...
