The suppression of the Native Americans and the decimation of
their culture is a black page in the history of the United States.
The discrimination and injustices towards this ancient race, which
had lived on the American continent long before the European conquerors
came to this land, are still present to this day despite the efforts
of different groups and organizations trying to restore the
justice.
The destruction of their culture is one of the most shameful
aspects of our history, the extent of the damage that was done is
still being down-played and denied entry into textbooks and history-lessons
to this day.
The origin and history of the Indigenous Peoples of the Americas
have been studied for years by researchers from different countries,
and a recent DNA study showed that the genealogy
of the western aboriginals is one of the most unique in the world.
The question of whether Native Americans
derived from a single Asian population or from a number of different
populations has been a subject of research for decades. Now,
having compared the DNA
samples from people of modern Native American and Eurasian groups,
an international team of researchers concluded on the validity
of the single ancestral population theory.
The study follows up on earlier research that found a unique
variant of a genetic marker in the DNA of modern descendants
of Native
Americans. While earlier studies have already supported
this conclusion, whats different about our work is that it
provides the first solid data that simply cannot be reconciled with
multiple ancestral populations, said Kari
Britt Schroeder of the University of California, one of the
authors of the study.
As a result of the previous research, the so-called 9-repeat
allele (or variant) was found in all of the 41 Native
American and Asian (from the western side of the Bering Strait)
populations that were sampled. At the same time, the allele was
absent in all 54 of the Eurasian, African and Oceanian groups that
were also sampled in the study.
The researchers supposed that the distribution of the allele
was due to the fact that all these ethnic groups (modern Native
Americans, Greenlanders and western Beringians) derived from
a common founder population, which
had been isolated from the rest of the Asian continent thousands
of years prior to their migration to the Americas.
This explanation was persuasive enough; however, there was no
strong evidence to support it. There were two other plausible versions
to explain the distribution of the 9-repeat allele among the modern
descendants of Native Americans.
If the 9-repeat allele had originated as a multiple mutation,
its presence in the Americas would not suggest common ancestry.
Thus, if there had been more than one ancestral founder population
and the 9-repeat allele had been present only in one of them, it
could possibly have passed to the other ethnic groups and spread
among them. If there also had been a second, beneficial allele located
very close to the 9-repeat allele, it would certainly have been
carried into new populations. At the same time, long stretches of
DNA
surrounding the 9-repeat allele would be carried along with the
beneficial allele due to the mechanisms of natural selection.
In order to check the validity of this hypothesis, researchers
led by Noah Rosenberg of the University
of Michigan analyzed
DNA samples from people from Asian, Native American, Greenlandic
and two western Beringian populations, and found that all the samples
with the 9-repeat allele had a distinct pattern of base pairs in
short stretches of DNA.
As Schroeder noted, If natural selection had promoted
the spread of a neighboring advantageous allele, we would expect
to see longer stretches of DNA than this with a similarly distinct
pattern. And we would also have expected to see the pattern in a
high frequency even among people who do not carry the 9-repeat allele.
So we can now consider the positive selection possibility unlikely.
These findings also excluded the multiple mutations theory,
because in this case there would have been myriad DNA
patterns surrounding the 9-repeat allele.
Our work provides strong evidence that, in general,
Native Americans are more closely related to each other than to
any other existing Asian populations, except those that live at
the very edge of the Bering Strait, concluded Schroeder.
The results of the study were published
in the journal Molecular Biology and Evolution.
About the author:
Anna LeMind is the owner and lead editor of the website Learning-mind.com,
and a staff writer for The
Mind Unleashed.
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