Monday, April 30, 2012

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

The seventh episode of Finding Your Roots with Henry Louis Gates, Jr., featuring Samuel L. Jackson, Condoleezza Rice and Ruth Simmons aired on PBS last night. All three of these African Americans had heard rumors that they had European ancestors, but had never had the opportunity to investigate the truth behind this until Dr. Gates asked them to participate in this series. While this episode's focus was on these notable Americans, it was very much Dr. Gates' story too, so bits of his own journey were interwoven throughout the episode.

Dr. Gates

Very early on in the episode, Dr. Gates informed us that he would be using DNA to help trace both the European and African roots of his guests. I was not disappointed with the role of genetic genealogy in this episode, although I would always like to see the science used even more extensively than is possible in this hour format. I thought it was a bit confusing following so many stories at once, so I had to take some time to really study the episode before writing this post.

The first DNA portion dealt with the question of Dr. Gates' own oral family history that told of his direct paternal line descending from a white man named Samuel Brady. His genealogy team was able to track down a direct descendant of Samuel Brady in order to compare their genomes. Since Samuel Brady was Dr. Gates' presumed great great grandfather this means that the team optimally needed to find a descendant of Brady who was one generation closer to him. This is because only approximately 90% of third cousins (which is what they would be if this Brady descendant was the same generation as Dr. Gates) will share enough DNA from their shared great great grandparent to be detected as a genetic match. If they were unable to find a great grandchild of Samuel Brady, another option would be to use Dr. Gates' deceased father's DNA (I'm assuming they still have some in storage) in the comparison or to also test other siblings and/or cousins from Dr. Gates' family who descend from the same paternal line. I am not sure which route they used, but since Dr. Gates consulted with the illustrious geneticist Dr. George Church on this segment, I am confident that there can be no doubt in their conclusion that Dr. Gates is not a descendant of Samuel Brady.

Dr. Gates non-DNA match with the Barber descendant

Dr. Gates' voiceover mentioned another DNA test that he used in this quest, "Another test proved that whoever this man [his direct paternal great great grandfather] was, he was most probably of Irish or Scottish descent." Although not elaborated on in this episode, Dr. Gates is referring to a Y-STR test that he had performed on his Y-Chromosome DNA. In this test a male is able to discover information on his direct paternal ancestral line's origins. In Dr. Gates case, his Y-DNA fits into the Ui Neill Subclade thought to descend from an Irish King named Niall of the Nine Hostages. More details on Dr. Gates search can be found here. (This type of test can be performed by Family Tree DNA.)

The brief conversation between Dr. Gates and Dr. Church yielded a few very helpful quotes for those struggling to understand autosomal DNA testing that I would be remiss not to transcribe here. First he corrected a popular misconception by mentioning that saliva is used for these genetic scans, not blood. Then, Dr. Church explained random autosomal DNA recombination, "Each generation you get a scrambling, you get a rearrangement of the DNA...basically there's a half of the DNA from any generation." Dr. Gates then expounds upon what this means for those if us undergoing autosomal DNA testing in the voiceover, "That means you inherit approximately a quarter of your genome from your grandparents [each] and a sixteenth from your great great grandparents [each], so if two people do share a recent ancestor, they will also share long stretches of identical DNA." These matching stretches of DNA are what 23andMe and Family Tree DNA are looking for when they calculate the results for our Relative Finder and Family Finder match lists. When they are able to detect stretches of identical DNA that are sufficient to suggest a recent relationship, these people who match us are reported as predicted cousins. (Autosomal DNA tests can be ordered through 23andMe or Family Tree DNA's Family Finder.)

Dr. George Church founder of The Personal Genome Project

Condoleezza's family had passed down an oral tradition that their paternal ancestress Julia Head was descended from a slave owner named Burrows Woodward Head. Dr. Gates team tracked down Burrows' great granddaughter Rose Mary Head English to perform an autosomal test to compare to Condoleeza's DNA as described above. Geneticist Dr. Joanna Mountain from 23andMe explained, "If they truly are third cousins, we can hope to see some matching DNA, a longer stretch of matching DNA." Once again, as in Dr. Gates case, there was no DNA match. As I mentioned before, for a third cousin relationship, I would recommend additional testing of other family members since about one in ten third cousins will not show a match, but since Condoleezza and Rose Mary are actually second cousins once removed and would be expected to share twice as much DNA on average as compared to 3rd cousins (1.563% versus .781%), it is quite definitive that it was not a match.

Joanna Mountain on "Finding Your Roots with Henry Louis Gates, Jr."

Not content with this negative result, Dr. Gates' team also ordered an admixture test for Condoleeza. This DNA analysis revealed that her genetic makeup is 51% African, 40% European and 9% Native American or Asian. (The tool used for this analysis was 23andMe's Ancestry Painting and is included with their Personal Genome Service.) This proves that although they were unable to determine specifically who Condoleezza's white ancestors were, she definitely has quite a number of them on her family tree.

Next Dr. Gates' team compared the DNA of Ruth Simmons to that of her presumed third cousin Camber Hayman, both descended from the Grapeland, Texas Beasley Family (possibly Charles). Finally, there is a positive match in this episode! Ruth and Camber share 25 cM of DNA across their autosomes (about .33%). This is a predicted 3rd-4th cousin relationship because the amount shared falls between the average amount of DNA expected for a third and fourth cousin (.781% versus .195%). Dr. Gates explains, "The DNA does not tell us the exact generation, but you and Camber share an ancestor since 1800." This is because once the relationship is past second cousins, the random nature of autosomal inheritance makes it difficult to ascertain the exact relationship without more extensive testing of other known relatives.

Ruth Simmons' genetic comparison to Camber Hayman

The truth regarding Samuel's presumed European ancestor, Joel Branham, was presumably too far back for Gates' team to try to sort out using an autosomal DNA test since he was would have been his 3rd great grandfather. The further back an ancestor is in your pedigree, the more difficult it becomes to prove the connection through autosomal DNA testing. It is still possible to do so in the case of a third or fourth great grandfather, but requires extensive testing of extended family on both sides of the equation, an undertaking more fitting for a research project than an hour long television show.

As usual, I wanted the analysis to go further and reach more definitive conclusions. Expert genetic genealogist Dr. Tim Janzen was thinking along those same lines when he wrote to me, "Dr. Gates could have gone another step in his analysis that linked Ruth Simmons to her Beasley ancestor... [he] could have done more autosomal tests on more relatives of Ruth Simmons who were descendants of Mr. Beasley and then compared the data to that of additional relatives of [Camber]. If he had done this...he may have been able to accumulate enough information that he could establish with reasonable certainty which Mr. Beasley was Ruth Simmons' ancestor." Since we saw Ruth's brothers in the episode meeting their cousin Camber, we know that there were at least two other family members whose DNA could have been compared against Camber's. Of course, I realize that trying to fit the family stories of three people into a single episode would not allow for this depth of analysis (but I can dream).

Ruth Simmons meeting her cousin Camber Hayman

For each of the guests, Dr. Gates used the company African Ancestry to recapture some of their deep ancestral information. This company works with Y-Chromosome DNA and mitochondrial DNA (mtDNA) testing, so it can only illuminate the deep ancestry of the guests' direct paternal line (father's father's father, etc...) and their direct maternal line (mother's mother's mother, etc...). This leaves out all of the ancestors in the middle branches of the family tree, but can help trace at least one or two of their "Kunta Kinte ancestors" as Dr. Gates calls them.

Chart of Y-DNA and mtDNA ancestors.
Those ancestors in white are only reached through Autosomal DNA.

Dr. Gates and Dr. Rick Kittles, the scientific director of African Ancestry, did a good job of explaining the process of matching the mtDNA and Y-DNA of "living members of the ethnic groups more highly represented in the transatlantic slave trade" with African Americans today. The theory is that if an African American has a match with one of the African residents in the database, then they share a distant ancestor and can thus deduce the likely origin of their direct paternal or maternal ancestor from what they know of the origins of their African match. Some have argued that these tests are not valid since the tribes in Africa have not stayed static over the centuries and/or the database is not broad enough to ascertain the true genetic origins, but I do not have the expertise to address these objections and would leave it to the reader to do their own research on this subject. (The only issue that I had with the segment was when Dr. Kittles said that the Y-DNA and mtDNA are "identical in every generation". This is not strictly true since they both mutate occasionally.)

Map of the African ethnic groups represented in African Ancestry's database

Since the female guests could only have their mtDNA testing done since they do not possess a Y-Chromosome, their brothers were tested when possible. The results of these tests were compared against the company's extensive database of samples from Africa. Each of the guests were informed which ethnic group their Y-DNA and/or mtDNA matched with the most closely, implying a genetic connection to these areas. Dr. Gates also included the middle school students from the Continuum Project in this exercise. It was exciting to see each of the students excited to connect back to their roots in Africa and hear what it meant to them.

Continuum Project students learning about their African roots

The most surprising result of the night belonged to Ruth Simmons. Her mitochondrial DNA traced back not to Africa, but to the Americas. Apparently, Ruth is the only guest tested in this entire series whose direct maternal line traces back to a Native American. Dr. Gates joked that she was the only African American that he knows whose "great great great great grandmother was a Cherokee Princess." Dr. Tim Janzen suggests that it is more likely that Ruth's maternal line descends from the Caribbean (possibly the Taino or Carib Indian tribes) than from the Cherokee Indians. He opines that this would have been a good time for Dr. Gates to have discussed the origin of much of the Native American admixture in African Americans today. Dr. Janzen explains, "It appears that slaves in the Caribbean were significantly admixed with the native population. Some of those slaves were imported into the US and contributed a significant amount into the African American gene pool." (See here and here for background.) Since Ruth's mtDNA did not reveal an African ancestral line, Dr. Gates tested her brother to learn the deep origin of her direct paternal line. It was indeed of African origin, matching the Kota people of Gabon.

Ruth Simmons' mtDNA's deep origin traces to the Americas

Condoleezza was surprised to learn that her mtDNA traced back to the Tikar people of Cameroon because she said when she visited, the people in Ghana had thought that she looked like she might descend from their Ashanti Tribe. What was not mentioned was that since the mtDNA is only relevant to one of her many ancestral lines, she could well have Ashanti ancestors another ancestral line. Samuel seemed happy to discover that his Y-DNA most closely resembles the Benza people of Gabon. Dr. Gates was clear when he explained that this was an effort to find the origins for just two of the guests' ancestral lines, but to each of them after years of having no information on their African origins, it was obviously a lot.

Condoleezza Rice's mtDNA's deep origin traces to Cameroon

At one point in the episode, Dr. Gates mentioned that "few African Americans have ever been able to discover the facts behind these stories". Although the DNA tests in this episode were not wholly successful in identifying the European ancestors of Dr. Gates and his guests, I am confident that, with time, the technology and the databases will grow to such an extent, that success will be possible for most, if not all, of those searching for their roots.

Next week Dr. Gates will explore the diverse ancestries of Martha Stewart, Margaret Cho and Dr. Sanjay Gupta. Would it be wrong for me to reverse my usual wish and say that I hope that the show uses DNA testing a little less next week? (This took me ALL day!)

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

Monday, April 23, 2012

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

The sixth episode of Finding Your Roots with Henry Louis Gates, Jr., investigating the mixed ancestry of Robert Downey, Jr and Maggie Gyllenhaal, aired last night on PBS. These two actors not only share a profession, but both have a mixture of Eastern European Jewish ancestry as well as deep American roots. Because of these commonalities, I thought their stories worked well together. I was thoroughly entertained by this episode for three reasons: 1) I love Robert Downey, Jr., 2) I discovered that Maggie is my cousin through our shared 10th great grandfather John Lothrop and 3) The appearance of Bennett Greenspan, President of Family Tree DNA (or as Professor Gates called it "", which I am sure was much appreciated).

Bennett Greenspan on "Finding Your Roots with Henry Louis Gates, Jr."

Unfortunately, the DNA portion was only about five minutes long again this week (starting at 43:00), nevertheless it felt a bit more substantial to me than last time. I was happy to see a number of different tests featured: 23andMe's Ancestry Painting, FTDNA's Population Finder and mtDNA testing.

Robert Downey, Jr.'s "Ancestry Painting" from 23andMe

First, Robert Downey, Jr., whose father is half Jewish, was presented with a pie chart of his 23andMe Ancestry Painting, which breaks down a person's genetic ancestral origins into three populations - European, African and Asian. (Note - this test is included in the 23andMe Personal Genome Service and is presented as a chromosomal chart rather than a pie chart.) Dr. Gates has repeatedly stated that this test reveals "European, African and Native American ancestry", however I would like to remind readers that the Asian reference population simply "stands in" for Native American. 23andMe does this because the genetic makeup of the two populations is similar, but in reality, this is not quite the same as having reference samples from Native Americans and the two should not be confused with each other. For instance, a person could show Asian DNA on their Ancestry Painting, but one should not automatically reach the conclusion that they have Native American ancestry because they may have ancestors from China, Japan, Korea or any other Asian region. If a person has reason to suspect that they possess Native American ancestors and knows of no other Asian ancestry, then this test is useful for that purpose. As is typical of most people, RDJ guessed that his ancestry would be more "interesting" than it was and seemed disappointed to learn that his Ancestry Painting showed 100% European ancestry. As I have mentioned before, this actually encompasses all of Europe, including the Middle East, so it doesn't rule out RDJ's Jewish ancestry.

Robert Downey, Jr.'s "Population Finder" from Family Tree DNA

Next, Dr. Gates presented RDJ with what I believe was his Population Finder admixture from Family Tree DNA. (The PopFinder feature is included with the Family Finder test.) This test broke down RDJ's ancestral origins a bit more, showing that he is about 20% Middle Eastern or Jewish.  That is slightly under what we might expect for him with a father who is half Jewish, so his one Jewish grandparent may have had a little something else mixed into his/her ancestral origins.

Later, Dr. Gates sat down with Maggie to discuss her mitochondrial DNA (mtDNA) which is inherited straight down the maternal line, passed from mother to child as far back "as you can think" enthused Maggie. Maggie's mom is Jewish, so it makes perfect sense that Maggie's mtDNA has been inherited from one of four Jewish founding mothers who lived thousands of years ago. The voiceover explained, "Scientists have concluded that 40% of Eastern European Jews share genetic lineages that reach back two to three thousand years, remarkably to just four about 3.5 million people descend from one of these four maternal ancestors." Haplogroup Project Administrator and genetic genealogist Vince Tilroe points out that Bennett Greenspan and Professor Gates were most likely speaking of mtDNA Haplogroups K1a1b1a, K1a9, K2a2a, and N1b when referring to the four Jewish maternal lines. These were identified in the 2006 study by Dr. Behar, "The Matrilineal Ancestry of Ashkenazi Jewry: Portrait of a Recent Founder Event".

Bennett Greenspan of FTDNA explaining Jewish DNA to Dr. Gates

Bennett further explained that Maggie had "hit the jackpot" with about 150 exact matches in Family Tree DNA's mtDNA database.  Bill Hurst, Administrator of the mtDNA Haplogroup K Project and a leading expert on this haplogroup, theorizes that if Maggie's mtDNA haplogroup is K, she likely falls into the K1a1b1a ancestral haplotype. Hurst explains that this haplotype's match numbers most closely coincide with the those that Bennett cited from FTDNA's database. At the HRV1/HRV2 level of testing, this haplotype now has 194 exact matches, but at the time of filming may have had closer to 150. He also notes that K2a2a is now called K2a2a1 due to recent discoveries. (There are three levels of mtDNA testing offered by Family Tree DNA which you can read about here.)

At the end of the episode Professor Gates discussed the question of "nature versus nurture" with his guests and asked Robert Downey, Jr. if he feels that his ancestral past has shaped who he is today. In answer, RDJ insightfully commented, "I don't see how it couldn''s informing you whether you're conscious of it or not, so probably better to be conscious." The episode ended with RDJ expressing his feelings about this experience with Dr. Gates, explaining that he felt that this was just the beginning of his journey of self-discovery.

I hope this show has also inspired all of you to begin (or continue) the journey into your ancestral roots. See you next week when we review the genetics of Samuel Jackson, Condoleezza Rice and Ruth Simmons. The television listing says that the show will be using DNA to "determine which parts of Africa their ancestors came from." That sounds promising!

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

Thursday, April 19, 2012

DNA Day Sale at Family Tree DNA starts tonight!

If you haven’t heard it is again DNA Day tomorrow and Family Tree DNA felt that was good enough to have a short two day sale.

Nearly the entire offering will be on sale these two days, including upgrades that were not on last year's sale.  The sale will begin at 6PM Thursday April 19th and will conclude at 11:59PM on Saturday April 21st.
There will be no need for a coupon - all prices will be automatically adjusted on the website.

New Kits

Current Group Price SALE PRICE
Y-DNA 12** $99 $59
mtDNA** $99 $59

Y-DNA 37 $149 $129
Y-DNA 67 $238 $199
Family Finder $289 $199
mtFullSequence (FMS) $299 $249

Y-DNA 12 + mtDNA $179 $118
FF + Y-DNA 12 $339 $258
FF + mtDNA $339 $258
FF+ Y-DNA 37 $438 $328
FF + mtDNAPlus $438 $328
Comprehensive (FF + FMS + Y-DNA 67) $797 $657


Y-DNA 12 $89 $59
mtDNA add-on $89 $59
Y-DNA 12-37 Marker $99 $69
Y-DNA 37-67 Marker $99 $79
Y-DNA 12-67 Marker $199 $148
mtFullSequence upgrade (HVR1 to Mega) $269 $199
mtFullSequence upgrade (HVR2 to Mega) $269 $199
mtFullSequence add-on $289 $219
Family Finder add-on $289 $199
Login to place your order.

Well, it is nice to see that at least one company is keeping up the tradition! Well done, FTDNA!

**These tests must be ordered through a Project. Search for your surname or a relevant geographic region to join one. If you can't find one that you can join, please send me an email at and I will assist you.

[Disclosure - my company StudioINTV has an existing production agreement with FTDNA that has no bearing on the opinions I express. I also receive a small commission from FTDNA on non-sale orders through my affiliate link, which I use to fund DNA tests. I am currently serving in a volunteer advisory position for 23andMe, for which I may receive a small number of 23andMe kits for my DNA research.  Any opinions that I express here on my blog are my own and do not reflect those of management at either company.  I receive no other compensation in relation to any of the companies or products referenced in my blog.]

Monday, April 16, 2012

"Finding Your Roots with Henry Louis Gates Jr." - DNA in The Fifth Episode

The fifth episode of Finding Your Roots with Henry Louis Gates Jr., which featured religious leaders Rick Warren, Angela Buchdahl and Yasir Qadhi, aired last night on PBS. This means we are halfway through the miniseries! As we have progressed through the episodes it appears to me that Gates and his team are featuring DNA testing progressively less and less. This is a shame and I hope this trend will reverse itself in the second half of the season.

The DNA portion of the show last night comprised only about 5 minutes (starting at 44:55), but drew some interesting genetic comparisons between guests of different religious backgrounds, demonstrating again that DNA testing is "deconstructing the notion of race" (quote from Gates in an earlier episode). Qadhi's Y-DNA haplogroup or what Gates referred to as his "paternal haplogroup" which was inherited from his father's father's father, etc... is J2. This haplogroup is common among those with Indian ancestry like Qadhi, but also "reaches levels of about 20% in Ashkenazi Jews". Qadhi said that he didn't find this too surprising since "Muslims and Jews consider themselves cousins...(as) descendants of Abraham."

Yasir Qadhi reviewing his Y-DNA Haplogroup

Qadhi also had a surprising "matrilineal cousin" in a guest from an earlier episode -  Barbara Walters - with whom he shares his mtDNA haplogroup which was inherited from his/her mother's mother's mother, (etc...). Unfortunately this haplogroup was not revealed in either episode, so we can only guess what it may be. I would imagine that in each case, while sharing the major haplogroup, Qadhi of Indian ancestry may belong to a slightly different subclade than his Jewish cousins. (See the Y-Haplogroup J Project for details.)

Less surprising, Rabbi Buchdahl is also a distant cousin to Barbara Walters. Gates said that Buchdahl and Walters share a common ancestor within about the last 300 years. He mentioned "three segments" in common between them. This test was clearly an autosomal DNA test by 23andMe or Family Tree DNA's Family Finder. Normally three matching segments of DNA would imply a significantly closer relationship than distant cousins, but among the highly endogamous Ashkenazi Jewish population, this is not uncommon. I was pleased to see Gates team incorporating all three types of DNA used for genealogy in this segment.

Angela Buchdahl reviewing her father's Warnick Y-DNA (?)

In the voiceover starting at 46:15, Gates explains, "DNA Analysis can tell us...where our earliest ancestors originated thousands of years ago, to whom we might be related today and the percentages of our African, European and Asian ancestry over the past 500 years." I thought that this may have caught some viewers' interest, so I wanted to detail which tests he was referring to in that comment.

The first part of the quote - "where our earliest ancestors originated thousands of years ago" -  refers to deep ancestry that is revealed through our Y-DNA and mtDNA haplogroups, tracing the migration of mankind. You can learn your haplogroups from 23andMe's DNA test or by taking the Y-DNA STR test and/or the mtDNA test at FTDNA.

Next, "to whom we might be related today" refers to autosomal DNA tests that match you with cousins from your more recent ancestry by examining matching blocks of DNA between testers. These types of autosomal tests are currently only offered by 23andMe and FTDNA. 23andMe's "Relative Finder" feature is included in their single test and FTDNA's test for this purpose is called "Family Finder".

Lastly, "the percentages of our African, European and Asian ancestry over the past 500 years" refers to biogeographical ancestry analysis or admixture tools like 23andMe's Ancestry Painting or FTDNA's Population Finder. In this case, he was specifically referring to 23andMe's Ancestry Painting. This is the most basic of genetic ancestral origin tools only using the three populations mentioned. FTDNA's Population Finder breaks down genetic origins into more granular populations and 23andMe's Ancestry Finder feature does so as well, with a somewhat different approach.

Earlier episodes have shown the pie chart with the guests' ancestral origins or genetic admixture by percentages. In this episode, we caught a glimpse of Pastor Rick Warren's dark blue chart, signifying 100% European. While he and Gates laughed at this result, it isn't necessarily as boring as it might sound since, in this case, "European" encompasses ancestry from all over Europe including Russia, France, Germany, Finland, the British Isles, the Middle East, Scandinavia and many other countries.

It would have been interesting to see all of the guests' Ancestry Paintings in this episode because there would have been much commonality between them. As a person of Indian heritage, Qadhi would have likely possessed a large European component and a smaller Asian one and Buchdahl's chart, being half Jewish and half Korean, would have probably been equally split between Asian and European. (Upon further review of the episode, it appears that I was correct - see below.) The specific differences between the Asian and European ancestry among the guests would only be revealed with a more detailed breakdown, such as FTDNA's Population Finder or 23andMe's Ancestry Finder.

Angela Buchdahl looking at her "Ancestry Painting"

Next week we will be privy to details of the family trees (and hopefully DNA!) of movie stars Robert Downey Jr and Maggie Gyllenhaal. That sounds like fun! See you then...

I have been writing a review of the DNA testing used in each episode:
Week 1 - Episode 1 and 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

Monday, April 9, 2012

"Finding Your Roots with Henry Louis Gates Jr." - DNA in The Fourth Episode

Last night PBS aired the fourth episode of Finding Your Roots with Henry Louis Gates Jr. which featured husband and wife Kyra Sedgwick and Kevin Bacon. The episode concentrated on exploring the couple's deep American roots, stretching back to the early days of the Colonies.

Husband and wife Kyra Sedgwick and Kevin Bacon

Unfortunately, there was very little genetic genealogy in this episode. At the very end, Dr. Gates presented Kyra with her DNA results explaining, "Using traditional genealogy, we were able to trace her father's line back hundreds of years...but using DNA Analysis we were able to go even deeper into her past on her mother's line establishing her Jewish ancestry genetically." First Dr. Gates showed Kyra a chart. In editing they inserted a shot of a chart illustrating the path of Y-Chromosome DNA which is passed down from father to son. Since she is a woman and they were discussing her mother's side, I believe that they were actually analyzing her mitochondrial DNA haplogroup which is passed from mother to child. The voiceover said that they were looking deep into the past of her mother's line, so she likely has a mtDNA haplogroup that is associated with Ashkenazi Jews.

Chart from "Finding Your Roots" showing the path of Y-DNA

Then they looked at a chart from 23andMe's Ancestry Finder and Dr. Gates explained, "Here's a graph of your 23 chromosomes and what it says is that 50% of all of your genetic material that they examined traces back to Ashkenazi Jews."  Note that he adds the qualifier "that they examined". This is because the Ancestry Finder feature only reaches conclusions about the portions of your DNA that have people who match it in their system, so most people do not have 100 percent coverage on this tool. Ancestry Finder is based on the answers that your DNA matches provide on the 23andMe survey "Where Are You From?" and, therefore, bases its analysis on the stated birth places of your matches' grandparents. (For more information on this feature, please see the post that I wrote about Ancestry Finder when it was first introduced.) The Ancestry Finder feature allows a user to click a box to see which of their matches have self-identified their grandparents as Ashkenazi Jews. For Kyra, this was apparently the case with approximately 50% of her total matches on Ancestry Finder. Instead of showing a screenshot of the graph of her "23 Chromosomes" which would have illustrated this result, they showed an image of her Ancestry Finder list of matching populations (seen below). This list of matching populations identified by Ancestry Finder also supports Dr. Gates' team's conclusion that Kyra has substantial Ashkenazi Jewish ancestry since the ones at the top of the list are typical in my experience for  those with Jewish ancestry.

Kyra Sedgwick's 23andMe Ancestry Finder from "Finding Your Roots"

At the end of the episode, Dr. Gates revealed to Kyra that her fear of being cousins with her husband Kevin Bacon was confirmed and that she and Kevin are 9th cousins once removed. Although fun for entertainment purposes, in the context of genetics, this is pretty meaningless since chances are that neither of them has any genetic material remaining from their shared ancestor(s). If they were to both test their autosomal DNA at 23andMe or with Family Tree DNA's Family Finder, they would likely not find any significant common DNA between them (unless they have closer yet unidentified shared ancestors). Since Dr. Gates team likely did test them both at, at least, 23andMe, I suspect my assumption is correct. This is because with each successive generation of random autosomal DNA inheritance, the contribution of each ancestor gets broken into smaller and smaller pieces and the majority of our ancestors have "fallen off of our genetic family tree" by the time you reach back past a couple hundred years. (Blaine Bettinger of "The Genetic Genelaogist"explains this concept here.) That is why autosomal DNA tests for genealogy like 23andMe and FTDNA's Family Finder work best for researching more recent ancestry.

I am looking forward to next week's episode with Rick Warren, Angela Buchdahl, and Yasir Qadhi and hope to see more integration of genetic genealogy. In the preview, I caught a glimpse of my friend, 23andMe's geneticist Mike Macpherson (one of the creators of Ancestry Finder). I can't wait to see his appearance on the show!

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

Monday, April 2, 2012

"Finding Your Roots with Henry Louis Gates Jr." - DNA in The Third Episode

Last night PBS aired the third episode of Finding Your Roots with Henry Louis Gates Jr. which featured journalist Barbara Walters and educator Geoffrey Canada. The episode revolved around investigating the guests' paternal roots by tackling the challenges of discovering the original surnames of their fathers' ancestral lines. Geoffrey's was obscured mostly due to his extremely limited knowledge of his father's family. Although Barbara had previously had her family tree researched, her immigrant ancestor's name change had not been discovered.

After discovering that Geoffrey Canada's paternal line was descended from Thomas Cannaday, a slave owned by a Charles Cannaday of Franklin County, Virginia, Geoffrey's Y-Chromosome DNA was analyzed to determine if his great-great grandfather Thomas may have been fathered by his slave owner. Not surprisingly, Canada does possess a European Y-Chromosome Haplogroup. In fact, he apparently shares his haplogroup with Kevin Bacon, Robert Downey, Jr. and Harry Connick Jr.  Since the majority of men in the Bacon DNA Project, the Downey DNA Project and the sole man in the Conrick DNA Project (possibly a variant of Connick) possess the R1b1a2 Y-Haplogroup (the most common in Europe), it is likely that Geoffrey's Y-DNA Haplogroup is also R1b1a2. This piece of information is not enough to solve the puzzle though, since there is no way to know for sure when that European ancestor entered Geoffrey's direct paternal line, so Dr. Gates' team identified two great grandchildren of Charles Cannaday and asked them to take an autosomal DNA test to determine if their great grandfather is the same man as Geoffrey's 3rd great grandfather. If the working theory was correct, that would mean that these Cannaday descendants are Geoffrey's 2nd cousins twice removed and would be expected to share about .781% of their DNA (the same amount as third cousins). In this case, there is a chance that the autosomal test could be ineffective due to the fact that only about 90% of third cousins have enough shared DNA to be detected by this kind of test. Although it would certainly be worth a shot, this scenario could be stretching the capabilities of autosomal DNA testing just a bit. Even if they were to have a small amount of shared DNA, without extensive testing of other descendants, it might be difficult to say with certainty that the DNA came from this potential shared ancestor rather than another, especially since we know both families' ancestors lived in the same geographical area. In my opinion, a Y-STR DNA test on Charles Cannaday's direct paternal descendants (or his father's, uncle's or brothers' direct paternal descendants) would be more conclusive because it would determine if Geoffrey is carrying a Cannaday Y-Chromosome or not. Unfortunately, the theory did not get to be tested anyway because, in the end, both of the Cannaday descendants identified by Gates' team declined to participate in DNA testing. Dr. Gates, with deadlines looming, was probably forced to leave the question unresolved for now. Many of us genetic genealogists know how it feels to track down the perfect candidate to test out a genealogical theory, only to find that the person identified is unwilling to take a DNA test. It is always disappointing, but given the luxury of time, perhaps his team wouldn't have stopped there. Since the local Cannaday researcher said that she had 3200 Cannadays in her database and that it was still a very common name in the area, the team could have either looked for descendants of Charles Cannaday's father or asked his great great grandchildren to test. (I have found the younger generations are often more willing.)  In either case, the potential relationship to Geoffrey would have been one more step removed, thus decreasing the chances of a match even further, but still worth investigating.

Obsessive genetic genealogist that I am, I just couldn't let the Y-STR idea go, so I searched for a Canada/Cannaday DNA Project to try to determine if there were any Cannadays already tested, against whom Geoffrey's Y-STRs could be compared. I was initially surprised to find that no project of this name exists, however I did find a Kennedy DNA Project that lists variants Canaday and Canady. Upon further investigation, I found that there are 15 Canadas, 12 Canadys, six Cannadys, seven Canadays and one Cannaday who have tested at Family Tree DNA (they may not all have taken a Y-STR test). If you look at the Kennedy DNA Project's Results Page, you will find some of them there. There are seven participants of interest - four named Cannady, one Canady, one Canaday and one Canada. Six of these seven fall into the haplogroup R1b1a2. (The one who does not is identified as being descended from a Charles Canaday, but there is no information supplied as to birth or location.) It may be that none of these are directly descended from the direct paternal line of Charles Cannaday of Franklin County, Virginia, but just for kicks, it would be interesting to see if Geoffrey's Y-STRs match any of these participants. I wonder if Dr. Gates' team investigated this avenue.

Like last week, geneticist Joanna Mountain from 23andMe appeared on the episode - this time to explain the Y-DNA analysis. Interestingly, in this segment there appears to be two spots where there are inaccuracies in regard to this DNA test. The first one occurs starting at 41:15 when Dr. Gates asked Dr. Mountain, "So a Y-DNA analysis, in other words, is what people in the barber shop talk about the paternity test?" and she (appears to have) answered, "It sure is."  The exchange seems awkward and I believe this mistake was made in editing. I am sure that Dr. Mountain would never imply that a Y-DNA test is the same thing as a paternity test since it unquestionably is not. (I think what happened is that her comment was not actually in response to that questions, but was pasted in from another part of the segment.) A traditional paternity test is based on autosomal STRs markers, like CODIS . While it's true that a Y-DNA test could informally be used as such, in reality it cannot tell us if two people are father and son, only that they come from the same direct paternal line. (They could actually be brothers, uncle/nephew, first cousins, second cousins, etc...) The second mistake was probably merely a slip of the tongue on the part of Dr. Gates, but still worth clarifying since genetic genealogy is so new to many of the viewers. Starting at 43:35, Dr Gates explained what the results of this Y-DNA test mean for Geoffrey, "We do know without a shadow of a doubt that a white man fathered your female slave ancestor [bold mine] and entered your family line." I'm sure he meant to say "impregnated your female slave ancestor" since it was actually Geoffrey's male ancestor that was fathered by a white man. We know this because the Y-DNA only follows the direct paternal line. By definition, women cannot be introduced into this line because they do not inherit a Y-Chromosome. I don't mean to call anyone out on these mistakes, but I do think it is important to explain and clarify in an effort not to confuse any viewers new to the concept of genetic genealogy.

The next time DNA was mentioned in the episode was when Dr. Gates asked Barbara what percentage of her DNA she thought was of Jewish origin and she guessed 99.9%. An admixture test, which appeared to be FTDNA's Population Finder (included with the Family Finder test) revealed that she is actually ~91% Middle Eastern (Jewish) and ~9% European (non-Jewish). Dr. Gates noted that this exercise with Barbara illustrated that DNA analysis is revealing that "our family trees are more diverse than we had assumed."

This concept is proving true for African Americans as well. "In the African American community, genetic evidence of our rainbow-colored roots is challenging long-held assumptions about what it means to be black," Dr. Gates explained.  To illustrate this, reminiscent of last week's scene in the barber shop, Dr. Gates asked several students from Geoffrey's school to estimate how much of their DNA is African, European and Native American. After swabbing their cheeks, the students were surprised to find from their admixture tests (which appeared to be from 23andMe) that their ancestry was more diverse than they first imagined.  After learning that a portion of her DNA was European one student said, "I didn't know that I was European.. now I don't consider myself just black." Gates emphasized that these tests "deconstruct the notion of race" and reveal that "we are all mixed up".

I'm very pleased that DNA was again a vital component of this episode, but a little disappointed that they weren't able to use it more conclusively to determine Geoffrey's paternal ancestry. I guess that is realistic though and better than implying that genetic genealogy is always easy. By the way, can you believe Barbara Walters is 82?! She must have some pretty darn good DNA! I thought it was kind of funny that her family's original surname Waremwasser sounded an awful lot like Gilda Radner's Baba Wawa. I look forward to next week's episode with Kevin Bacon and Kyra Sedgwick. I hope they perform autosomal DNA tests on the couple to see if Kyra's fear is true and they are indeed "kissing cousins". See you then!