Photo: Qiaomei Fu, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences
Scientists studying 400,000-year-old proteins have uncovered a surprising twist in the human evolutionary story, suggesting that the human family tree is more like a complex, interwoven “bush” than a simple linear progression.
Researchers analyzed six teeth attributed to Homo erectus found at archaeological sites in China. Using preserved enamel proteins, they identified genetic variants in the protein ameloblastin that revealed unexpected links between ancient human groups.
One of the detected variants appears unique to East Asian Homo erectus populations, suggesting a previously unknown regional lineage. More strikingly, another variant matches one previously found in Denisovans, an elusive group of ancient humans closely related to both Neanderthals and modern humans.
The finding implies that these groups likely overlapped and may have interbred at some point in prehistory. This supports a growing scientific view that ancient human populations were not isolated branches, but frequently interacted and exchanged genes when they shared habitats.
Overall, the study reinforces the idea that human evolution was not a straight line, but a network of interconnected populations with repeated genetic mixing across different regions and time periods.
