The Origin of Native American Man:
A Look at Possible Migrations of Pre-Historic Man Into North America
The origins of Native American people have been a topic of debate in academia for decades. There have been several theories, up to and including the possibility that Native Americans arrived via alien intervention. The origins of Native Americans are much less fantastic. Native Americans are descended from ancient Eastern Asians, who crossed into the New World sometime before 14,000 BC. Until recently, archaeology could only speculate on this notion. Recent research in the field of molecular biology is proving this ...view middle of the document...
Mitochondrial DNA Evidence
Several studies into the importance of Mitochondrial DNA (mtDNA) have been performed in the last few decades. mtDNA is important because of it’s
rapid rate of evolution and it’s inheritance through the maternal line (Horai et al. 1992). Haplotypes, or groups of alleles on a chromosome that are transmitted together. These traits make the mtDNA a valuable tool to discern genetic relationships among individuals. The genetic differences, or morphs, can then be traced to ethnic and geographic origins, providing insight into lineages (Schurr et al. 1990).
One of the major hurdles to discovering the origins of Native Americans was to discover the exact haplotypes that could be considered the founder maternal lineage groups, or the “genetic pool“ from which most Native Americans could claim heritage. Most scientists agree that there are four major founder haplotypes, and that most full-blooded Native Americans contain one of these four types (Bailliet et al. 1994). These four types are generally referred to as A, B, C, and D. Recent studies have identified a fifth haplotype, referred to as X (E. Starikovskaya, 2005).
Several studies into mtDNA and lineage have been performed on various Eastern Asian populations. One influential study performed in 1998 examined 145 Siberian Eskimos and Chukchi, together known as the Chukotka (Y. Starikovskaya). Researchers observed three prominent haplotypes (referred to as A, C, and D) that were evident in the genetic makeup of the Chukotka. Of particular note was the high frequencies of haplotype A, which is consistent with high frequencies seen in Native Americans from the Northwest Coast and Alaska. However, there was no evidence of type B or X, two of the core haplotypes of Paleo-Indians. This has lead the researchers to posit that there were perhaps more than one migration event. The first, from Siberia, lead to the dispersal of A, C and D, and a second, also possibly from Siberia but more recent, migration that carried the B haplotype.
Another study confirms this, stating that haplotypes A, C, D occur in Northwestern and Northern Siberia, and haplotypes B and X occur in in the Southern periphery of the continent (Starikovskaya et al). The researchers specifically pinpoint two possible locations for the migrations; the Altai-Sayan Upland of Siberia, and the Lower Amur River region. Together, the migrations from these two areas contributed the genetic material that makes up the large majority of Native American genetic sequences.
Another way that mtDNA can be used is to track when the ancestors of Native Americans crossed into the New World. Until fairly recently, archaeologists and scientists presumed that the earliest settlement in the Americas occurred approximately 12,000 YBP by a group known as the Clovis culture. However, using mtDNA divergence, it is estimated that the haplotypes A, C, and D were first expanded into the New World approximately...