Maternal variation in Huichol and Mixtec populations from Mexico

Thus, the new American maternal lineages were recognized, leading the number of founding
lineages from 4 to 15: A2*, A2a, A2b, B2, C1b, C1c, C1d*, C1d1, C4c, D1, D2a, D3,
Dd4h3a, X2a and X2g (Achilli et al., 2008; Tamm et al., 2007; Fagundes et al., 2008; Perego
et al., 2009, 2010; Malhi et al., 2010; Hooshiar Kashani et al., 2012). The defining mutations
for all 15 haplogroups are present in Figure 2.
Haplogroups A2, B2, C1 (including it subgroups) and D1 are called major pan-American
founder haplogroups because of their frequency and the distribution pattern all over the
Americas. The rest are the minor founding haplogroups, which are present in a lower quantity
and are geographically restricted.
1.4 Migration theories
Although in the last decade the studies of Native American mtDNA have shed light to
population movements into the Western Hemisphere, the arrival time(s), the migration routes
and number of expansion events in the Americas remain controversial.
After the discovery of the Clovis culture in New Mexico in 1929, there has for many years
been a predominant hypothesis among archaeologists, that Clovis people were the first
inhabitants of the Americas, living 11,500-10,900 ybp (Haynes et al., 1992, 2005). Clovis was
the first well-established human culture in the Americas. The Clovis-first theory was
supported with the discovery of a number of other Clovis sites in wide area from Southern
Canada to Mexico, possibly to Southern America (Pearson and Ream, 2005). However, there
have been found other ancient sites which indicated human presence in the Americas much
earlier, for example: the Monte-Verde site in Chile with the estimated age of ~14,600 ybp
(Dillehay, 2008), the Meadowcroft Rockshelter in Pennsylvania dating to 22,000-18,000 ybp
(Adovasio and Pedler, 2004), the Buttermilk Creek Complex in Texas which shows that
people already lived in North America 15,500 ybp (Waters et al., 2011). Findings over the
past few years and a re-examination of old ones have convincingly shown that humans were
present in the Americas before Clovis culture arose. Pre-Clovis occupation model is in
agreement with genetic data.
The high diversity level and the distribution pattern of the major Pan-American haplogroups
together with their similar coalescence time estimates, has been used to support a singlemigration
model (Forster et al.,1996; Bonatto and Salzano, 1997; Merriwether et al., 1995).
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