Research Paper: Africa to Out of Beringia

Pages: 5 (1420 words)  ·  Bibliography Sources: 1+  ·  Level: College Junior  ·  Topic: Native Americans  ·  Buy This Paper

SAMPLE EXCERPT:

[. . .] The period of settlement on this side of the land bridge was sufficiently long enough to allow genetic diversification to occur through genetic drift prior to subsequent outward migratory events. During this period, these five ancestral lineages emerged as four major haplogroups (A2, B2, C1, and D1) and five minor haplogroups (C4c, D2a, D3, D4h3, and X2a).

Eventually, the surviving populations began to migrate again, most likely south along the west coast before spreading out across North and South America. This migration is the basis of the "Out of Beringia" theory and explains how the Americas became populated by H. sapiens. The "Out of Beringia" theory is also supported by the Uto-Aztecan language distribution from the California coast to Nicaragua and the Oto-Manguean language distribution from Northeast Mexico to Nicaragua and Honduras. The possibility that two other migration routes out of Beringia existed was recently suggested when mtDNA for the rare haplogroups D4h3 and X2a were completely sequenced to reveal distinctive variations. For example, the minor haplogroups X2a is now known to be restricted to Native Americans populating the northern regions of North America. This finding suggests that another migration probably occurred out of Beringia about 15,000 to 17,000 ya, but in an easterly direction.

Populations migrating south towards South America would have encountered the geographical barrier called the Mesoamerican isthmus. The narrow strip of land linking the two continents probably created a geographically-imposed bottleneck that further restricted genetic diversity in Amerindians populating South America. When the genetic diversity of Native Americans populating Mesoamerica was examined the four major Native American haplogroups were found.

Mesoamerica represents a region rich in cultural diversity, with 11 linguistic families encompassing 68 major linguistic groups and 291 living and seven extinct languages. The distributions of the haplogroups detected were as follows: A2 (50.5%), C1 (28.5%), B2 (17.6%), D1 (2.7%), and D4h3 (0.4%). The admixture content of contemporary Native Americans in Mexico is 89.1% Native American, 5.4% European, and 4.5% African, which suggests the populations native to this area have remained relatively insulated from the effects of admixture. The genetic diversity between the 11 different native populations is also relatively minor, suggesting that geographic and/or social isolation has allowed genetic drift to be the primary source of genetic variation within these populations.

The total amount of genetic diversity found by a study examining the genetic, linguistic, and cultural diversity among Native Americans inhabiting Mesoamerica was 19.23% (Sandoval et al., 2009), but most of this was due to the inclusion of two groups of Native Americans from the Northern regions of Mexico (19.7%; Pima and Tarahumara). In contrast, a comparison between groups from central and southern Mexico revealed only minor genetic diversity (4.35%, p = 0.15). Among the study participants, four major linguistic families were present: the Oto-Manguean, Uto-Aztecan, Tarascan, and Mayan. When the study participants were grouped by the four major linguistic families there was insufficient variation at the mtDNA HyperVariable Region I to find a pattern of genetic diversity that could predict which individual belonged to which linguistic family.

This study of Native American populations within Mesoamerica has revealed how populations sharing the same ancestral gene pool can become isolated enough to develop distinct languages and cultures, but in the absence of significant levels of discriminatory genetic variation. This result stands in contrast with the results of previous population genetics studies examining the cultural and linguistic histories of the 14 ancestral clusters in Africa. Based on this and other studies, geographic isolation seems to be an important antecedent for using genetic variation as a tool for tracking ethnic and linguistic evolution, as was shown among for the ancestral African populations, and when comparing central and southern Mexican populations to those inhabiting the north. As the genetic analysis tools become more powerful over time, able to sequence large segments of mitochondrial and autosomal genomes quickly and accurately, the identification of rare variations may become an essential tool for distinguishing some cultural and linguistic evolutionary events that have occurred over relatively short spans of history within genetically homogenous populations.

References

Campbell, M.C. & Tishkoff, S.A. (2010). The evolution of human genetic and phenotypic variation in Africa. Current Biology, 20, R166-R173

Sandoval, K.,… [END OF PREVIEW]

Four Different Ordering Options:

?
Which Option Should I Choose?

1.  Buy the full, 5-page paper:  $28.88

or

2.  Buy + remove from all search engines
(Google, Yahoo, Bing) for 30 days:  $38.88

or

3.  Access all 175,000+ papers:  $41.97/mo

(Already a member?  Click to download the paper!)

or

4.  Let us write a NEW paper for you!

Ask Us to Write a New Paper
Most popular!

Africa's Armies Robert B. Edgerton Term Paper


Compare North Africa to Sub-Saharan Term Paper


South Africa Economy History Research Paper


Why Does the World Ignore Africa? Term Paper


Ethical Issues of South Africa's Black Economic Empowerment Program Term Paper


View 1,000+ other related papers  >>

Cite This Research Paper:

APA Format

Africa to Out of Beringia.  (2010, December 2).  Retrieved May 25, 2019, from https://www.essaytown.com/subjects/paper/africa-out-beringia/8638639

MLA Format

"Africa to Out of Beringia."  2 December 2010.  Web.  25 May 2019. <https://www.essaytown.com/subjects/paper/africa-out-beringia/8638639>.

Chicago Format

"Africa to Out of Beringia."  Essaytown.com.  December 2, 2010.  Accessed May 25, 2019.
https://www.essaytown.com/subjects/paper/africa-out-beringia/8638639.