Around 14,000 years ago, a hitherto undiscovered Homo sapiens population lived in what is now southwestern China and contributed to the ancestry of ancient Americans.

Researchers report in Current Biology on July 14 that ancient DNA from a skullcap previously found at Mengzi Ren, or MZR, a location in southwest China’s Red Deer Cave, has revealed the evolutionary origin of this diverse Asian tribe.

The discovery presents a once-in-a-lifetime chance to pinpoint the origins of ancient Americans in the wide region of East Asia.

Nearly all of the fossil person’s mitochondrial DNA, which is generally passed from the mother, and around 3.3% of the nuclear DNA, which is inherited from both parents, were found by geneticist Bing Su of China’s Kunming Institute of Zoology and colleagues.

In some aspects, the fossils of early humans discovered in 1989 in Red Deer Cave resemble those of modern humans, while in other ways, they resemble Asian Neandertals and Homo erectus (SN: 12/18/19). The question of whether the Chinese fossils reflect H. sapiens or have other origins has been sparked by that peculiar skeletal mixture 

Credit: Marek Jantač

The MZR individual’s DNA is identified as that of a female H. sapiens from southern East Asia by the latest genetic analysis and comparisons with modern and ancient individuals. The ancient female’s ancestry includes minor contributions from Denisovans and Neandertals, much like East Asians do now.

Su’s team discovered that the MZR woman has genetic links to humans who lived in the Americas as far back as 12,000 years ago. Scientists believe that some ancient southern East Asians crossed a land bridge to North America after traveling up China’s eastern coast, maybe via Japan.