If is more often the case that the scientists have their theories correct, but the general public misunderstands or is misled by the media reports.
Human DNA can respond to and provide a large variety of adaptations for the living environment.
One must understand that the word ‘species’ is based on ‘adaptation to environment’.
Why should we even doubt that there are , and have been , a large ‘variety’ of ‘humans’?
At my age, memory is suspect. However there is a rock shelter site which was excavated by the French, at Ob Luang, Northern Thailand, which had modern human remains at a age of approximately 25 K years. It’s not a great distance to Yunnan.