So Elizabeth’s Warren’s family legend was correct. She joins Barack Obama … in his case Ann Dunham, usually called his “white” mother was a descendant of the first African sold as a slave in colonial Virginia!
A genetic analysis of Elizabeth Warren’s DNA shows he does have native American ancestory about 140 years ago … sometime after the American revolution in the period of great westward expansion of the settlers.
So her family legend was correct. She joins Barack Obama … in his case Ann Dunham, usually called his “white” mother was a descendant of the first African sold as a slave in colonial Virginia!
Prof. Carlos D. Bustamante, Ph.D.
Date: October 10, 2018
Executive Summary. We find strong evidence that a DNA sample of primarily European descent also
contains Native American ancestry from an ancestor in the sample’s pedigree 6-10 generations ago. We find little or no evidence of African ancestry in this sample.
Request.
To analyze genetic data from an individual of European descent and determine if there is reliable
evidence of Native American and/or African ancestry. The identity of the sample donor, Elizabeth
Warren, was not known to the analyst during the time the work was performed.
Background.The individual’s DNA was previously sent to a DNA testing laboratory for genotyping, with a DNA microarray. The resulting DNA genotypes were sent to Dr. Bustamante for analysis. An expert in genetic ancestry analysis carried out the computational work described below under Dr. Bustamante’s supervision.
Methodology.
Analysis was performed to scan the human genome to identify individual chromosomal segments with European, African, East Asian, and Native American ancestry, using the RFMix computer program, which was developed by us (Maples et al., 2013) and is one of the leading methods for ancestry analysis. The ancestry analysis used reference samples from various regional populations used in human genetics (see below). Because available samples do not provide complete coverage of all Native American groups, some segments with Native American ancestry may be missed. In addition, it is not possible to reliably associate smaller segments having Native American ancestry with any specific tribe or group.
Samples.
The individual’s sample contained information on 764,958 sites of genetic variation across the human
chromosomes, of which 660,173 overlapped with sites in the reference set used for ancestry analysis.
Our population reference set consisted of 148 individuals (a continental reference panel of 37
individuals from across Europe, 37 from Nigeria with Sub-Saharan African ancestry, 37 from across the Americas with Native American ancestry, and 37 individuals from China). To determine whether the Native American ancestry results in the sample were unusually high relative to other individuals of European ancestry, analysis was also performed on 185 individuals from two reference sets from the 1000 Genomes Project— Americans of predominantly European ancestry from Utah (n = 99 individuals) and British individuals of European ancestry from Great Britain (n = 86 individuals).
Results. The results were as follows:
(1) The great majority of the individual’s identifiable ancestry is European: 95% of high confidence
segments (defined as those segments with at least 99% posterior probability of assignment) were
identified by RFMix as being of European origin. This is likely an underestimate as many of the segments not classified as high-confidence are also likely to be European in origin. The analysis also identified 5 genetic segments as Native American in origin at high confidence, defined at the 99% posterior probability value. We performed several additional analyses to confirm the presence of Native American ancestry and to estimate the position of the ancestor in the individual’s pedigree.
2.
(2) The largest segment identified as having Native American ancestry is on chromosome 10. This
segment is 13.4 centiMorgans in genetic length, and spans approximately 4,700,000 DNA bases. Based on a principal components analysis (Novembre et al., 2008), this segment is clearly distinct from segments of European ancestry (nominal p-value 7.4 x 10-7, corrected p-value of 2.6 x 10-4) and is strongly associated with Native American ancestry.
(3) The total length of the 5 genetic segments identified as having Native American ancestry is 25.6
centiMorgans, and they span approximately 12,300,000 DNA bases. The average segment length is 5.8 centiMorgans. The total and average segment size suggest (via the method of moments) an unadmixed Native American ancestor in the pedigree at approximately 8 generations before the sample, although the actual number could be somewhat lower or higher (Gravel, 2012 and Huff et al., 2011).
(4) The sample was compared to the results of the 185 reference individuals with European ancestry,
from Great Britain and Utah.
• The segment on chromosome 10 observed in the individual is larger than any of the segments
identified as having Native American ancestry in any of the 185 reference individuals.
• The total length of Native American segments observed in the individual is greater than the
average value for the reference individuals — by 12.4-fold (corresponding to 12.7 standard deviations) for the individuals from Great Britain and 10.5-fold (corresponding to 4.9 standard deviations) for the individuals from Utah.
(5) The sample also contained smaller segments that could not be reliably assigned to any specific ancestry group (at 99% posterior probability). The total length of these unassigned segments was 366 centiMorgans, and they span 267,650,000 DNA bases.
Conclusion. While the vast majority of the individual’s ancestry is European, the results strongly support the existence of an unadmixed Native American ancestor in the individual’s pedigree, likely in the range
of 6-10 generations ago