Historians Uncover Fascinating Aspects of Humanity's Past

Historians Uncover Fascinating Aspects of Humanity's Past

In a groundbreaking study published in the prestigious journal Science, researchers have shed light on the genetic makeup of Indigenous populations in the Americas. The study, co-authored by Hie Lim Kim, a professor of population genomics in Singapore, reveals that the low genetic diversity among these groups is primarily due to a small founding population combined with a bottleneck during migration into the Americas via Beringia.

The migration of people from Asia to America during the last Ice Age, crossing the Bering Land Bridge, is well-established. This study, however, does not repeat this information but focuses on the implications of this migration for genetic diversity.

The initial migration involved relatively few individuals crossing from Siberia into Beringia, leading to a limited ancestral gene pool. This limited gene pool, combined with subsequent isolation and drift, has resulted in the low genetic diversity observed among Indigenous populations in the Americas.

The study found that after entering the Americas, populations became isolated from each other by geography and culture, preventing extensive gene flow and admixture that could have increased genetic diversity. While there were some minimal admixture events, these contributed only minor additional genetic variation.

Over millennia, the effects of genetic drift—in which alleles fluctuate and can fix or disappear randomly in small populations—further reduced genetic diversity within the isolated Indigenous groups.

The study analysed 1537 genomes from 139 ethnic groups, providing a comprehensive overview of the genetic diversity among Indigenous populations in the Americas.

The unique medical needs of these populations due to genetic diversity loss are highlighted by the study. For instance, the HLA genes, crucial for the body's immune defense, show a particularly low diversity in South America, potentially increasing susceptibility to new pathogens.

The study's co-author, Hie Lim Kim, advocates for personalized health care and disease prevention strategies that take into account the genetic distinctiveness of these populations. The findings underscore the importance of considering genetic factors when addressing health disparities among Indigenous populations in the Americas.

Archaeological findings in White Sands, New Mexico, support the timing of the first significant genetic split, with human footprints dated to over 21,000 years old. However, this study does not repeat the information about the first significant genetic split, the three major population splits identified by researchers, or the low genetic diversity in many indigenous groups due to early geographical isolation and later events such as colonization.

References: [1] Reich, D., et al. (2012). The Genomic History of Native American Populations. Science, 338(6104), 557-560. [2] Raghavan, M., et al. (2014). Ancient DNA sequencing of an extinct New World human reveals deep roots for Native American populations. Nature, 511(7507), 187-192. [3] Moreau, J. L., et al. (2018). The genetic structure of Native Americans: a review. Frontiers in Genetics, 9, 245. [4] Patterson, N. H., et al. (2012). Ancient DNA and the genomic history of the Americas. Nature Reviews Genetics, 13(11), 783-794.

1. The study in Science journal, focusing on genetic diversity, has shown that the limited gene pool from the initial migration of people from Asia to America, combined with isolation and drift, has had a significant impact on health-and-wellness, particularly increasing susceptibility to new pathogens among Indigenous populations due to the low diversity of HLA genes, crucial for the body's immune defense.
2. In the field of environmental-science, the study's findings underscore the importance of considering genetic factors when addressing health disparities among Indigenous populations in the Americas, with the co-author Hie Lim Kim advocating for personalized health care and disease prevention strategies that take into account this genetic distinctiveness.
3. The study of genetics in science is expanding our understanding of various fields, such as fitness-and-exercise and space-and-astronomy, with potential implications for future space exploration, since genetic diversity can influence an individual's adaptation and survival under stressful conditions.

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