Genetic Analysis Reveals the U.S. is Truly a Melting Pot

By Carl Engelking | December 19, 2014 3:10 pm

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The United States is often described as a cultural melting pot. The degree to which that’s true socially can be debated  and, at least as regards to race, it has been debated lots lately.

But another way to look at that question could be to examine the mixing in Americans’ genetic ancestry. And that’s just what researchers at 23andMe, a genomics and biotech company, have done. Their analysis of 160,000 Americans revealed subtle differences in genetic ancestry as it relates to race across the United States.

Americans Up Close

Anyone interested in tracing his or her ancestry can purchase a genetic testing kit from 23andMe for $99. The company will analyze your sample and provide you with a full report detailing specific information about your DNA. Over time, 23andMe has assembled a massive database of over 800,000 genotyped customers.

From this broader population researchers selected 148,700 European Americans, 8,700 Latinos and 5,200 African Americans who had consented to allow their data to be used in research. Researchers wanted to determine how people’s self-identified races or ethnicities  in this case, African American, Latino, or European American  correlated with their genes, depending on which part of the U.S. they were living in. Specifically they examined traces of Native American, African, and European genomes by looking for so-called single nucleotide polymorphisms, one-letter changes in the DNA sequence.

Patterns of Genetic Ancestry

Not surprisingly, researchers found that most people have traces of several ethnicities in their DNA, although we usually only identify as a single one when describing ourselves. What was more interesting was how this relationship varied by region, often reflecting historical events from many generations ago.

The slave trade, for example, brought thousands of Africans to the United States. Most of the major slave ports in the U.S. were located in the South, which is reflected by a greater amount of African ancestry in the genomes of both white and African American people in the South. Researchers estimated that more than 5 million whites in the U.S. have at least 1 percent African ancestry in their DNA. Louisiana’s high level of African ancestry in self-identified whites is consistent with historical accounts of intermarriage in the New Orleans area.

23andme

The researchers also found that more than 5 percent of African Americans carry at least 2 percent Native American ancestry. The highest proportion of African Americans with Native American ancestry was in Oklahoma, where black slaves were a significant part of the population in the 1860s and where the many Native Americans were displaced to after the Trail of Tears in the 1830s.

Among Latinos, researchers found that Iberian ancestry (Spain, Portugal) was particularly pronounced in those from Florida and the Southwest U.S. Researchers believe this ratio probably reflects early Spanish influence in these regions, as well as recent immigrations from Latin America.

Here are a few other quick finds from the analysis, which was published Thursday in the American Journal of Human Genetics:

  • Scandinavian ancestry in European Americans is highly localized in Minnesota and the Dakotas.
  • Eastern European ancestry was highest in Wisconsin, Illinois and Pennsylvania.
  • Native American ancestry in Latinos was highly concentrated in the Southwest with Texas and California leading the way.

A True Melting Pot

This analysis has its limits. 23andMe isn’t a free service and requires an Internet connection, which are both factors influencing the data. And 23andMe chose to focus on only a few of the racial and ethnic groupings in the U.S. due to data limitations. Researchers believe they’ll learn more about the ancestry of the U.S. population as they collect more DNA data.

But the results are still revealing. “Our results reveal the impact of centuries of admixture in the U.S.,” the researchers write, “thereby undermining the use of cultural labels that group individuals into discrete nonoverlapping bins in biomedical contexts…”

In other words, we all have a little bit of each other in our gene pools  a fact that can perhaps help spur unity in a divided modern world.

 

Photo credit: iko/Shutterstock 

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  • Sarah Levin

    “In other words, we all have a little bit of each other in our gene pools – a fact that can perhaps help spur unity in a divided modern world.”

    Since all countries and ethnicities do, except extreme isolates, I am not sure what the author is attempting to show other than they are late to the basics of gentics by two or three decades.

  • http://john-shuey.blogspot.com/ John Shuey

    Not mentioned, but relevant: About 2.7% of the average 23 & Me client’s DNA is Neanderthal. (Mine is 3%)

  • Wendell Lee

    This is because of term called “passing” in the South and why white southerners came up with the so called 2% rule. I have heard a ton of stories from my older relatives and have seen very light skinned African Americans pass for white then marry white people and no longer associate with any relative of darker skin blood line. This report should be of no relevance now in the 21st century but if you look at the news unfortunately it still does.

  • Wm Diehl

    Let me tell you I would never trust these guys. My first DNA report caused me to doubt that I was even related to my parents (both dead). It caused me to have a test taken to see if my sister and I were related. When that test came back confirming we were indeed siblings I confronted these guys and was given a new result that agreed with my own knowledge of my ancestry.
    I hope they have done a better job but I have my doubts.

  • richycat

    United States or America? USA is a country, America is a continent. US Citizens live in USA, Americans live in America (many countries not just one)

    • cnels

      I don’t think it is well known or accepted that “America” consists of both continents in the Western Hemisphere, North and South. Common usage almost universally considers the term “America” to be synonymous with the United States. Or do all the world’s commentators and news organizations have it wrong, and the Hair-Splitters have it right?

    • Diane McLean

      Only one country’s citizens are commonly known as “American.” In my travels overseas I’ve never encountered anyone who thought “American” referred to anyone but a citizen of the USA.

    • richycat

      That everybody uses American is not a good reason they are using it right. I can give you some other examples that shows “everybody” is not right. When you go throughout customs it says US Citizens and Visitors, not Americans and Visitors. Christopher Columbus didn’t discover a country, he discovered “the new world” later called “America”. The Olympics game flag, shows 5 rings… Do you know why? a hint: 5 continents: Europe, Asia, Oceania, Africa and….America. In South America, American means all those we live in the same continent. What would the English say if French uses European to call themselves, or Chinese to call themselves Asian as the owner of a the continent. Time to think.

      • Randy McDonald

        The Spanish and Portuguese languages are unique among major world languages in not using the ethnonym “American”.

    • mike

      I lived abroad for two years and worked with people from several countries… being from the United States, everyone called me an American. Those from Canada were called Canadians.

      • richycat

        How could they know they’re wrong if nobody tells them.

  • http://sjbhatti.blogspot.com/ SJBhatti

    123andme must conduct global researches in all continents provide results on human evolution. Why some countries, like Pakistan and India are whitewashed from such important field? They are not even allowed to know their genomes. Let us see how this wonderful science can help reduce poverty.

    • mary Wms

      The National Geographic Society is tracking Human evolution via the
      The Genographic Project

  • Robert Karma

    We are all star stuff, from the heart of stars we came and to the heart of a star we will return.

  • Jennifer Wenzel

    Wait…so you’re telling me that a whole bunch of research took place to tell me that Minnesota has a bunch of Scandinavians, there are Latino Native Americans in the Southwest, and Eastern Europeans in Wisconsin and Pennsylvania? I’m shocked. SHOCKED, I say.

    • Odin Matanguihan

      The “whole bunch of research” was most probably done by just using a few SQL statements. The data was collected for some other purpose, but since you have a pretty nice collection, it would be silly not to take a peak at what they might reveal.

    • xxaleenazxx

      And also that some whites have black ancestry.

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