A paper in the journal Cell that I missed when it was released a year ago, discussed at the magazine Science, analyzes 25 new ancient DNA samples from Russia's Amur region and compares them to existing ancient DNA samples and modern DNA samples in the region.
The paper finds that there was complete population replacement between the pre-Last Glacial Maximum population of Northeast Asia and the modern one ancestral to the current indigenous people of the Amur region that emerged around 19,000 years ago. This population is more closely related to modern East Asians and Native Americans, than to the pre-LGM people of Northeast Asia whose ancient DNA in available.
These Northern East Asians split about 19,000 years ago from Southern East Asians.
The paper's abstract and citation are as follows:
Northern East Asia was inhabited by modern humans as early as 40 thousand years ago (ka), as demonstrated by the Tianyuan individual. Using genome-wide data obtained from 25 individuals dated to 33.6–3.4 ka from the Amur region, we show that Tianyuan-related ancestry was widespread in northern East Asia before the Last Glacial Maximum (LGM).
At the close of the LGM stadial, the earliest northern East Asian appeared in the Amur region, and this population is basal to ancient northern East Asians. Human populations in the Amur region have maintained genetic continuity from 14 ka, and these early inhabitants represent the closest East Asian source known for Ancient Paleo-Siberians.
We also observed that EDAR V370A was likely to have been elevated to high frequency after the LGM, suggesting the possible timing for its selection. This study provides a deep look into the population dynamics of northern East Asia.