Jean M links to a Master's thesis, which discovered the following:I see no reason to believe the presence of haplogroup C indicates a "Mongoloid component". Stephen Oppenheimer sees C/Z mtDNA entering Mongoloids as part of an "intrusive" element "likely to have arrived from farther west in Asia, along with the eastern spread of the Upper Palaeolithic technology that appeared in Kara Bom in the Russian Altai 43,000 years ago." If this is correct, the presence of C in robust steppe Caucasoids would not be surprising. Oppenheimer has C/Z originating in western South Asia and entering Central Asia "round the western end of the Himalayas" 40-50,000 years ago, whereas Mongoloids (and "real" East Eurasian haplogroups) ultimately originate in SE Asia. Rather than indicating Mongoloid admixture "penetrated far into Eastern Europe", the presence of C mtDNA this early and this far west means one can't simply write off C and Z lineages in more easterly ancient Caucasoids (like some of those those buried at Xiaohe) -- or in Icelanders, for that matter -- as the product of Mongoloid admixture.
While most of our samples possessed mtDNA haplotypes that can be linked to European and Near Eastern populations, three Neolithic and all three Bronze Age individuals belonged to mtDNA haplogroup C, which is common in East Eurasian, particularly South Siberian, populations but exceedingly rare in Europe. Phylogeographic network analysis revealed that our samples are located at or near the ancestral node for haplogroup C and that derived lineages branching from the Neolithic samples were present in Bronze Age Kurgans. In light of the numerous examples of mtDNA admixture that can be found in both Europe and Siberia, it appears that the NPR and South Siberia are located at opposite ends of a genetic continuum established at some point prior to the Neolithic. This migration corridor may have been established during the Last Glacial Maximum due to extensive glaciation in northern Eurasia and a consequent aridization of western Asia. This implies the demographic history for the European gene pool is more complex than previously considered and also has significant implications regarding the origin of Kurgan populations.
[. . .] The Dnieper-Donets population was described as robust Europeoid by Soviet anthropologists as was the Andronovo/Afanasevo tradition further east. It is interesting that Mongoloid admixture has been detected in both groups. I would not have guessed that this would have extended that far west and south. It seems that M. G. Levin may have been right when he stated that the Mongoloid elements penetrated far into eastern Europe.
There is still the puzzle of where those 'intrusive' founders of the Mongoloid Mammoth Steppe colony (C, X, and Z) came from in the first place, and which of the three possible corridors into the Mammoth Steppe they took. These three north Eurasian lines are very uncommon south of the Himalayas. The sister branches C and Z reach their highest rates in Siberia and Northeast Asia, and are hardly found farther south at all except in India, Mongolia, Central Asia, and Tibet. They stretch in a broad east-west continuum across the Asian Steppe, achieving significant rates in Central Asia and even as far west as Turkey. Group C even got to America via Alaska, yet their northerly distribution in East Asia suggests they could not have moved up north from South east Asia via China. Rather, they are more likely to have arrived from farther west in Asia, along with the eastern spread of the Upper Palaeolithic technology that appeared in Kara Bom in the Russian Altai 43,000 years ago. They belong to the Manju group, and their ultimate ancestors appear to come from Pakistan or India, having moved up the valley of the Indus via Kashmir or Afghanistan round the western end of the Himalayas. This all suggests that they moved in to the Asian Steppe between 40,000 and 50,000 years ago from west Central Asia. Consistent with the concept that C and Z spread east across the steppe with Upper Palaeolithic technology, Toomas Kivisild has estimated the age of C in Mongolia at 42,000 years. [. . .]
The complicated mitochondrial picture described above suggests that Mongoloids derive primarily from the south, while Central Asian people come mainly from a West Asian source, but combined with additional East and Southeast Asian sources in Central and Northeast Asia. This genetic evidence then supports the geographical theory of a three-pincer colonization of Central Asian from the Indo-Pacific coast about 40,000-50,000 years ago. The dissection of the various admixed genetic contributions to Northeast Asia clarifies and is consistent with the concept of an ultimately Southeast Asian origin of Mongoloids peoples.