Although it has become universal to speak of the Mal'ta find's
admixture into
Native Americans, there is actually an alternative, more parsimonious
model that explains the data equally well, and that model is proto-Native American/paleo-Siberian admixture into Mal'ta boy. It's important to understand that no Mal'ta Boy genes have been found in Native Americans. Rather, Lazaridis et al. inferred Mal'ta
admixture into NA based on the differing genetic distances of various
Eurasian populations to Mal'ta Boy. Below are the f4 statistical
phenomenon that led Lazaridis to reach their conclusions:
1. Mal'ta is roughly equidistant in f4 stats to Oceanians and East Asians while closer to Native Americans
2.
Mesolithic Europeans and Mal'ta are roughly equidistant to East Asians
while Malt'a is much closer to Native Americans than Europeans are.
Model
A, Mal'ta admixture into Native Americans, would explain the above
phenomenon. However, it requires 2 hypothetical populations: Ancestral
North Eurasian and Basal Eurasian.
Model B, proto-Native American/paleo-Siberian admixture into Mal'ta, requires no hypothetical populations.
Model A
One
way to explain these curious mathematical artifacts is through a model
of Mal'ta admixture into Native Americans. Because Native Americans are
admixed with Mal'ta, they are closer to Mal'ta. Because East Asians are
unadmixed wit Mal'ta, they are as distant to Mal'ta as faraway Oceanians
are to Mal'ta. Because Native are admixed with Mal'ta, they are much
closer to Mal'ta than they are to Europeans, whereas because East Asians
have neither Mal'ta nor European admixture, both Euroepans and Mal'ta
are equidistant to East Asians.
A complication to this
model is that it requires the positing of 2 hypothetical populations,
Ancestral North Eurasian and Basal Eurasian, neither of which can be matched into archaeological
reality.. Mal'ta as a pure population
would require it to be a separate Ancestral North Eurasian because it
is very distinct genetically. Because Eastern Eurasians, Native
Americans, Oceanians are all closer to Mesolithic Europeans than they
are to Near Easterners. This would require pre-Neolithic Europeans to
form a macro-clad with other Eurasians to the exclusion of Near Eastern
Basal Eurasians.
Model B
The 2nd model is actually more parsimonious because it explains the interlocking genetic distances
of various Eurasian populations without a need for hypothetical populations. Because Native Americans are actually quite distinct from East
Asians and show up on a multi-dimensional plot in its distinct "corner",
any Native American admixture into Mal'ta would not make them noticeably
closer to East Asians, thus explaining the perplexities 1 and 2 above.
The Mal'ta --> Native American model creates serious archaeological and epigenetic/physical anthropology conundrums:
1. Both Ancestral North Eurasian and Basal Eurasian that Lazaridis et al.
proposes are hard to match up with any archaeology. Mal'ta-Buret
Culture arrives in Siberia 20,000 years after the initial Upper
Paleolithic there, and Mal'ta-Buret has long been noted as an intrusive
element in Siberia with a mixture of European Gravettian cultural
artifacts and Central Asian lithic characteristics.
2. The whopping ~40% admixture into Karitiana would also not explain why
Native Americans are on the extreme end of East Eurasian epigenetic
traits (i.e. EDAR, Sinodonty). While on average Native Americans and
modern East Asians are rather distinct, physical anthropologists do not
find Native American skull craniomorphology and craniometrics to be a
watered down version of East Asians, and in fact Plains Indian and
Mongolian defleshed skulls resemble each other more than both to
Chinese, Japanese, etc.
[hr]
Other problems with the Mal'ta find:
Their closest approximant are the Mari people of Uralic Russia. In the clustering analysis (at K10), the Mari are about 30% Siberian, which peaks at the Ngansan around 100%. Mari mtDNA is 13.2 East Eurasian.
source: Diversity of Mitochondrial DNA Haplogroups in Ethnic Populations of the Volga–Ural Region
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.408.4187&rep=rep1&type=pdf
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