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"Warren could even be less Native American than the average American."
– press release of the Republican National Committee, October 15, 2018
"Pocahontas (the bad version), sometimes called Elizabeth Warren, is being criticized. She passed a fake DNA test that revealed that she could be 1/1024, much less than the average American. "
– President Trump, in a tweetOctober 16th
Senator Elizabeth Warren (D-Mass.) Released the results of a 15 October DNA test revealing that she had an Amerindian ancestor.
The results – which identified the DNA of Native Americans from six to ten generations ago – were immediately misinterpreted.
It all started with a Boston Globe report, which initially indicated that the test had shown that she was between 1 / 32nd and 1 / 514th Amerindian. After confessing a calculation error twice, the Globe corrected this error between 1 / 64th and 1 / 1024th. This would translate between 98.44% and 99.9% do not American by birth.
The RNC then issued a press release according to which a 2014 New York Times reporter reportedly stated that "Americans of European origin had a genome made up of an average of 98.6% of Europeans, 19 % African and 0.18 years old. "It looked like Warren. less Amerindian DNA than the average American European.
We even posted a tweet to that effect (at a time when the Globe still said the range was between 1/32 and 1/1024):
(Twitter)
But it turns out that journalists and politicians do not understand genetics very well. So we are going to set the record straight after reviewing the results in detail and consulting genetic experts.
Facts
Warren's DNA was sequenced and analyzed by a group led by Carlos Bustamante, renowned geneticist from Stanford University. The researchers studied a fraction – much less than 1 / 1000th – of Warren's DNA, and then compared it to the DNA of 148 people from Finland, Italy, Spain, China, Nigeria and North America and South. An additional comparison was made with 185 people from Utah and Britain.
As expected, the vast majority of Warren's DNA indicated European ancestors. But five genetic segments have been identified, with 99% confidence, as being associated with Amerindian ancestry. The most important segment identified was chromosome 10.
"Although the vast majority of the ancestry of the individual is European, the results strongly support the existence of an unmixed Native American ancestor in the pedigree of the individual, probably between 6 and 10 generations ago, "says the report.
This is where the reports went wrong. The report indicated that Warren had 10 times more Native American ancestry than the Utah reference set and 12 times more than the whole of Britain. The report also states that the long segment on chromosome 10 indicates that DNA comes from a relatively recent ancestor.
These are important results. But the journalists focused on the language, indicating a range from the sixth to the tenth generation. This created the perspective of an ancestor among hundreds of great-great-great-great grandparents. The image below of eight generations (256 ancestors), via the UC Davis Genetics Lab, indicates the speed with which generations develop (the red corresponds to the female and the blue to the human ). It presents a uniform distribution, with each successive ancestor contributing equally to the DNA of an individual.
Generations evenly distributed. (Coop Lab, University of California at Davis)
But ancestors do not contribute equally to genetic material over time. Here is the image of 11 generations of ancestors thanks to the genetic material they brought to a particular individual. Some ancestors contribute a lot, while others do not contribute at all. In other words, as you go back in time, the number of your ancestors continues to increase, but not as quickly as that of genealogical ancestors. Carefully examine the sixth generation and you will see powerful contributors of genetic material – and many weak ones.
How does the genetic material spread across generations? (Coop Lab, University of California at Davis)
The most important point is this: Warren's DNA test results are static. The percentage of Native American DNA in its genome does not decrease with previous generations. There could be an individual in the sixth generation – around the middle of the nineteenth century, which is similar to the Warren family tradition – or maybe a dozen or more ancestors going back to the tenth generation he about 250 years ago.
(Note: Bustamante did not have access to Native American DNA because of community mistrust that DNA results could affect tribal identity. native samples from Mexico, Peru and Colombia – There is abundant literature showing that the use of these groups as references is accurate when it comes to differentiating genetic ancestors at the global level, but no tribe of Warren could not be identified, except that she had one or more ancestors of Aboriginal peoples.)
This fundamental error in understanding the test results was compounded by the RNC reference to The 2014 New York Times article, which focused on a genetic profile of the United States, was based on a 160,000-person study drawn from the clientele of 23andMe, a personal-use genetics company. Journalists estimate that Warren's genome accounted for only 1.56% of Native Americans, the article states that "Americans of European descent possess genomes representing on average 98.6% of Europeans, 0.19% African and 0.18 ", giving the impression that Warren 's sample was even smaller than that of the average American.
Not so. Remember that we said that the Bustamante study said that she was 10 times more than the people of Utah? This is the relevant statistic, indicating that his claim of a Native American heritage is much stronger than most European Americans.
In fact, the 23andMe study used a different methodology, so it can not be compared to the Bustamante report. In addition, the reference to an average "European-American" is misleading, as the genetic makeup varies enormously, with the vast majority of European Americans having no Native American ancestry.
Mike Reed, the RNC spokesman who aired the Times article, said in response, "In the end, Elizabeth Warren has at most, a tiny amount of Native American heritage and it is obvious that she had absolutely no right to claim minority status when she was climbing the professional ladder to join the Ivy League. "
The test results certainly did not win the fans in the aboriginal community.
Kim TallBear, Associate Professor at the University of Alberta, stated that "the desire to locate a claim for Native American identity on a DNA marker inherited from a long-standing ancestor is a racial and colonial understanding of what is a Native American. . In an email, TallBear said that the own definitions of the legitimate identity of Native Americans or tribes according to Native Americans are not centered on long-standing ancestors identified through a test, but rely on a living community: name, indeed, people we probably know (huge LOL here) – his family, his community and his tribe. "
The Pinocchio test
We are not trying to defend Warren's decision to publish the test, but simply to clarify what the test shows. The media spoiled the interpretation of the results – then Warren's opponents used uninformed reports to further weaken the test results. We also fell into this trap and were too quick to send a tweet (now deleted) making an inaccurate comparison. We should not have relied on media reports before tweeting.
Warren's United States DNA, as identified in the test, may not be very bulky, but it is wrong to say that it represents only 1 / 1024th or less than the average European . Three Pinocchios all around – including our tweet.
Three Pinocchios
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