Monday, May 21, 2012

"Finding Your Roots with Henry Louis Gates, Jr." - DNA in the Tenth Episode

Last night, the final episode of Finding Your Roots with Henry Louis Gates, Jr. featured Michelle Rodriguez, Adrian Grenier and Linda Chavez. Although the three guests share Spanish Colonial ancestors, Dr. Gates noted that it is interesting that these celebrities who have such similar family trees each have a different view of their own identities: self-identifying as mixed-European, Native American and Hispanic. I was pleased to see that Dr. Gates "turned to two of America's top genetic research firms, Family Tree DNA and 23andMe" to assist in exploring their multiracial ancestries.

Exploring multiracial ancestries on "Finding Your Roots"

In the DNA portion's introductory voiceover (starting at 44:50), Dr. Gates explains, "DNA Analysis can tell us many things about our families, from where our earliest ancestors originated tens of thousands of years ago, to their ethnic and geographical distributions over the last five hundred years." In the first part of this statement, he is referring to the deep ancestry revealed through our Y-chromosome DNA and mitochodrial DNA haplogroups and, in the latter, to our admixture results like 23andMe's Ancestry Painting and FTDNA's Population Finder. In this episode, Dr. Gate's team utilizes both to find and confirm evidence of  the guests' ancestry.

Linda Chavez' Population Finder chart from FTDNA

For Linda, who considers herself a mix of European, there was a very interesting surprise. DNA admixture results support suggestions from early paper records and memories of symbolic traditions that Linda's family from New Mexico were likely part of the Crypto-Jewish community. Her Population Finder pie chart from Family Tree DNA reveals that she possesses 73.31% European, 5.82% Native American and 20.87% Middle Eastern ancestry.  Dr. Gates explained to her, "According to our researchers - the geneticists - your Middle Eastern result is strongly suggestive of Semitic or Jewish ancestry." Linda was surprised at just how much Jewish ancestry she appears to have. Prior to this type of DNA testing, she would have never known how significant this part of her ancestry really is.

New Mexico's Crypto-Jewish roots

Adrian had grown up strongly identifying with Native American culture, but the genealogy research of Dr. Gates' team had raised some questions about his claim of significant Native American ancestry. Adrian's eyes lit up with pride when his direct maternal line's Native American descent was confirmed by his mitochondrial haplogroup C12b. (A person can discover his or her mtDNA haplogroup by taking either a 23andMe test or Family Tree DNA's mtDNAPlus test.) 

Adrian beamed with pride when learning about his Native mtDNA

Dr. Gates explained that "C1b2 is recognized as one of the four haplogroups found among Native Americans." I think he is referring to mtDNA haplogroups A, B, C and D, but this statement is a bit of an oversimplification, especially since sub-haplogroups of X have also been found exclusively in Native Americans. The 2008 academic article The Phylogeny of the Four Pan-American MtDNA Haplogroups states:

As for mitochondrial DNA (mtDNA), it has been clear, since the early nineties, that mtDNAs of Native Americans could be traced back to four major haplogroups of Asian origin shared by North, Central and South American populations [3][7]. These were initially named A, B, C and D, and are now termed A2, B2, C1 and D1 [8]. Afterwards, a fifth haplogroup – now known as X2a – was described in Native Americans, but in contrast to the four “pan-American” haplogroups, its geographic distribution is restricted to some Amerindian populations of northern North America [8][12]. Later, two more haplogroups – D2a and D3 – were identified: D2a in the Aleuts and Eskimos [13], [14] and D3 only in the Eskimos [15], [16]. Most recently there were two further (uncommon) additions – D4h3 and C4c [14], [17] – bringing the total number of Native American haplogroups to nine.

Adrian looking at the frequency map of his C1b2 mtDNA

Dr. Gates stated that Adrian's admixture percentage for Native American was not "especially large", however from working with many people who have oral traditions of Native American ancestry, I felt that his 8.44% Native American was relatively significant, as Dr. Gates said "the equivalent of one great grandparent". (A great grandparent would be expected to contribute an average of about 12.5% of your DNA.)

Adrian's admixture results reveal 8.44% Native American

The fact that his results revealed 91.56% European DNA appears to support Dr. Gates' contention that the majority of the ancestral mixing between Natives and Spaniards took place early in Colonial times and was short lived. However, we must not forget that Adrian's father, John Dunbar, is primarily of Northern European ancestry, so his mother most likely has significant Native American ancestry, probably about 17%. (The admixture test used is 23andMe's Ancestry Painting or Family Tree DNA's Population Finder which is included with their Family Finder product.)

Next, Michelle Rodriguez was "appalled" to discover that she is primarily European - 72.4%.

Michelle learning that she is genetically primarily European

Her admixture results also revealed what seemed to be a more welcome surprise - 21.3% African.

Michelle's admixture result reveal substantial African ancestry

She was very disappointed to learn that she only possesses 6.3% Native American exclaiming, "I wanted to be Native American!" From my experience, she joins many Americans in this often repeated desire. As Adrian expressed at the end of the episode, DNA testing can be a life-altering experience, sometimes leading one to reinterpret their self-identity. He said that it would definitely change how he sees himself and how he represents his ancestry to others in the future.

Sadly, this brings us to the end of Dr. Gates' miniseries. I have been disheartened that both of the genealogy series aired their last episode this weekend, so I was extremely pleased to hear Lisa Louise Cooke's Genealogy Gems interview with Dr. Gates (33:00) where he discusses the fact that his team is already in pre-production for the next season of this series. Please hurry up, Dr. Gates, I can hardly wait!

Let's not forget that we all have the continuing opportunity to discover more about ourselves through genetic genealogy. I encourage you to start or continue this fascinating journey. Now that the show is over, I will have a chance to write more about my own DNA research. I hope you will keep reading.

I have been writing a review of the DNA testing used in each episode:
Week 1- Episode 1 & Episode 2 - Harry Connick Jr. & Branford Marsalis; Cory A. Booker & John Lewis
Week 2- Episode 3 - Barbara Walters & Geoffrey Canada

Week 3- Episode 4 - Kevin Bacon & Kyra Sedgwick
Week 4- Episode 5 -  Rick Warren, Angela Buchdahl & Yasir Qadhi
Week 5- Episode 6 - Robert Downey, Jr. & Maggie Gyllenhaal 
Week 6 - Episode 7 - Condoleezza Rice, Samuel L. Jackson & Ruth Simmons 
Week 7 - Episode 8 - Martha Stewart, Margaret Cho & Dr. Sanjay Gupta 
Week 8 - Episode 9 - Wanda Sykes, John Legend & Margarett Cooper


  1. CeCe,

    As always great review. I was in complete agreement with your assessment on Adrian's Native American--this likely showed the equivalent of one full-blooded Native American at the great to great-great grandparent level. I think they need you or someone like you to consult on their DNA segments. I'm glad to see them using DNA but it is dismaying to see all the misstatements and misinformation during the series. I hope that get more help in the future at interpreting the DNA results.

    You could pick almost anyone who is active on the Forums to give them better information.
    Thanks for letting us know there's another season in the works. Two of the 3 TV shows I watch regularly finished over the weekend---Hmmm more time for DNA research!

  2. I live in the Bahamas where I have traced my own Ancestral Roots by historical researches.This twenty (20)years of searching and traveling have taken me to the Southern United States, the Caribbean countries of Jamaica,Antigua, and into England.

    I have found the passage of my Ancestors out of Africa, and wanted Dr. Gates to confirm this.
    The discovery of my Ancestors has been interesting, and inspiring.Thank you also Ancestry .com, 'Bahamas Genealogy", "Parish Chest", and "Bahamas Gen Web".

    1. That sounds fascinating, Cat Island. Thanks for commenting!

  3. Dr. Gates: Could you refer me to a professional genealogist, who is reasonable, who I may get to verify the many ancestors I have found!! I have also collected Y-DNA-46 testing results that may be of some help?

    1. Hi, I don't think Dr. Gates reads the comments on my blog, but you can write to for a referral. Best of luck!