finding your roots

Ancestral Traits

Genealogy Team April 16, 2012

Just as jazz greats Harry Connick Jr. and Branford Marsalis wondered, in the first segment of the PBS series Finding Your Roots, whether they had musical ancestors, you too might wonder where you got your penchant for painting or your bright blue eyes.

Many traits, as you might imagine, are complicated — is someone a musician because of innate, and possibly genetic ability, or because of her environment? Are you outgoing or shy because of your genes, or because of how you grew up? In most cases it is likely a combination of both, but that may make it even more interesting to learn that your ancestors shared certain qualities you see in yourself, whether it be a special talent or a streak of stubbornness.

For some traits, it can be easy to see a resemblance. Many of us have gazed at old, faded photographs of our parents or grandparents (or more distant relatives, if we’re lucky!) in their younger years and marveled at how we can see ourselves in them. The connection can be something obvious, like wild unruly hair or a distinctive shape of the nose, or it can be as subtle as a smile.

Because of genetic discoveries, you can trace a few such traits through your DNA. Those bright blue eyes could be due to specific factors located in genes responsible for pigment, passed down through generations. Or, if you’re Asian, you might look around the table at family holidays and see the pink-flushed cheeks that accompany a glass of wine — also a trait known to have a genetic basis. Does your mother’s father have male-pattern baldness? If you’re a man, chances are that you’ll inherit this trait as well. For more on traits and inheritance see this cartoon video.

Research on the specific musical ability called “perfect pitch” suggests that this ability to recognize and produce musical tones is the combination of innate potential and early training. But we don’t yet know which genes are involved. Indeed, no one has discovered much about the genetics of traits like artistic ability or personality. Why hasn’t anyone figured these out yet?

If they carry one particular genetic variant, two individuals with brown eyes can have children with almost any color eyes.

Researchers have certainly searched for genetic contributions to handedness, personality, and musical ability. But it may be that the genetic models we assumed in those studies were too simple. In one common type of genetic study, researchers compare two groups of people – those with a trait (say, perfect pitch) and those without. They step through a million or more genetic “markers” or positions throughout the genome, and ask at each step, “Do the people with perfect pitch have more of one version of this DNA marker than do the people without perfect pitch?” This approach works well if many of the people with perfect pitch have the same genetic variant, and that variant influences the trait strongly. This doesn’t seem to be the case for many traits, however.

Two things will help researchers discover the genetic factors behind those traits we see shared in families. First, studies that include a very large number of people with and without a given trait will help us find common genetic factors that have even a small influence on the trait. By involving tens of thousands of people in studies, researchers have recently discovered genetic variants that influence freckling, sneezing in bright sunlight, and whether or not someone has a sweet tooth.

Second, a trait such as the love of vinegar and lemons that you share with your cousin may be influenced by genetic variants that are unique to your extended family. In that case full genome sequencing — that is, examination of all 3 billion positions in the genomes of a few family members — would be needed to get to the bottom of the family mystery.

DNA can tell us a lot about our ancestors and where we came from, and it turns out that it can also tell us a bit about why we’re the way we are. Perhaps that trait you share with someone in your family tree comes from a little shared DNA.

 
 
About the Author:
Shirley Wu completed her Ph.D. in Biomedical Informatics at Stanford University and now oversees 23andMe’s pipeline of detailed health reports and health-related features. She also contributes regularly to 23andMe’s blog. Currently Dr. Wu is Science Content Manager at 23andMe, Inc.

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Comments

  • April 19, 2012 at 7:34 pm

    I find tracing of family trees to be quite interesting. I often wonder if my findings are truly accurate and would like to know the cost of doing DNA testing. Would DNA testing actually tell me that I am related to 2 Signers of the Declaration of the United States and 2 Presidents? From what I’ve gathered it seems I have Lee – Harrison connection. Also, would PBS ever do a “Find Your Roots” investigation for someone like me?

  • Georgina Roxburgh Harris

    April 22, 2012 at 5:22 pm

    The DNA tests on this program seem very different from the ones done by, for example, National geaographic, which are so general as to be bland and essentially of little interest. Where do your dna tests come from and would it be possible to have one done?
    Thanks you,
    GRH

  • Remy W. Burns

    April 23, 2012 at 8:01 pm

    I would like to know where you order the DNA test that breaks down your racial composition, e.g. 15% Native American, 20% African American, etc.
    Thank you

  • sally sweeney bryenton

    April 25, 2012 at 10:07 am

    if some traits are dominate and some are recessive ,why are children of the same parents different…

  • SAE

    April 27, 2012 at 11:09 pm

    Want to find my roots

  • JoAnn

    April 28, 2012 at 9:53 pm

    I agree with Georgina, I did the DNA test through National Geographic and it means little to me. I would like to do the one that Professor Gates uses. My ancestry is Eastern European and would like a little more info on this side of my family.

  • Robert

    April 29, 2012 at 4:03 am

    “you too might wonder where you got your penchant for painting or your bright blue eyes”

    incorrect. i wonder where i get my penchant for bike/motorcycle and horse riding, plus my almond-shaped single-lid Mongoloid eyes!

  • Jessica Montoya

    April 29, 2012 at 5:21 am

    Hello!
    to @Remy W. Burns and @Georgina Roxburgh Harris, I believe this is the place/site were they do that. https://www.23andme.com. I hope it helps.

  • BAB

    April 29, 2012 at 10:06 pm

    Congratulations on great program. I have one complaint however.

    During the program, Condoleeza Rice was told that her mitochondral DNA came from the Tikar people of Cameroon. Condi then said that she had always been told, because of her facial features, that her ancestors came from a different place (Gabon?). I wish Dr. Gates has said: “It’s quite possible. The Mitochondrial DNA can ONLY tell us that ONE of your female anscestors was Tikar. The other anscestors, male and female, could all have come from Gabon. Instead, she and we in the audience were left with the impression that Ms. Rice is entirely of Tikar descent. That’s misleading.

    Suppose, for example, that her great great grandmother that was Tikar. Suppose that woman was kidnapped and brought to America as a slave. Now most people have 16 great-great grandparents, of which the Tikar woman is just one. Therefore, the results of Rice’s mitochondrial DNA test would ONLY show that Ms. Rice is at least 1/16th Tikar. If that’s the only clue we have, then she could be 15/16ths Gabonese, or Senegalese or any mixture of anything else. Further, we actually don’t know which generation on the matrilineal line had the last full-blood Tikar female (with a full set of Tikar genes). Perhaps there was intermingling in the generations prior to leaving Africa. The intermingling could have taken place 100′s or 1000′s of years before. Therefore, it could be that ALL of Condi’s other DNA came from some other group or groups, with the last remnant of Tikar anscestry existing ONLY in Condi’s mitochondrial DNA.

    So Condi’s facial features could easily and CORRECTLY reflect Gabonese anscestry. The truth is, we don’t know. I wish Dr. Gates had indicated that, because the general audience of this program are not shoolkids, and this program is meant to educate us, not mislead us with over-simplified, unwarrented conclusions.

    Other than that small complaint, I loved this program, will watch it again and recommend it to my friends and relatives.

  • Kim

    April 30, 2012 at 1:54 pm

    I would like to ask how to find out what country my birth father is from. How can I find out were to go to get this information?

  • Georgia Wild

    April 30, 2012 at 2:11 pm

    I too would like to know the name of the DNA test you use on your program, and where can I get it done? Also my father is deceased and my brother also. How can I trace my fathers DNA? Will my son’s have it?

  • Anita Pass

    May 1, 2012 at 7:32 am

    I also would like information regarding DNA testing determining racial origins. How wonderful to truly know from where we began.

  • May 2, 2012 at 12:15 pm

    For those asking where to get tested: The author is from 23andme and probably did not want to comment on their product. But, as I am a customer and have no other affiliation I will:

    https://www.23andme.com/ancestry/

    Realize that results are not always clear cut, can be more general than specific and everyone should be prepared for surprises. The user community can be very helpful if you have questions. (You don’t have to get tested to set up an account and participate in the forums.)

    I’m happy with their services, although as a genealogist, I wish a few more people using their Relative Finder tools were more active.

    Finally, Family Tree DNA also has similar tests one can take. I have taken the Y-DNA test there and am happy with their service as well.
    http://www.familytreedna.com/

  • Dale Russom

    May 3, 2012 at 5:05 pm

    I am on Ancestry.com and they will be offering the DNA test very soon. I have already signed up for it . I have been a genealogist sine 1985 and it is the most interesting thing I have every done. I have, also, done some research for my boss, who is Africian American. He was thrilled.

  • Jamal David

    May 8, 2012 at 11:31 am

    I would love it if you can do my family tree it would mean the world

  • Cathy Parsons

    May 10, 2012 at 9:08 am

    Is there a questionaire I can hand out at our family reunion this summer to find out who likes vinegar & lemons? and other things like freckles, eye color and so on? It would be fun and revealing! Maybe I will make one up if you don’t have something like this. Thanks for all the great info….it is appreciated. LOVE THE SHOW!

  • Jacquelyne A. Roberts

    May 22, 2012 at 3:54 pm

    I love the show ‘Finding Your Roots’ with Mr. Louis Gates, Jr. I would love to know more about my ancestry. Can you tell me how I can have this done. I was born in Canada. Do they have an Ancestry.CA where I can get some information? Please help me in this regard. Thank you.

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About the Series

The basic drive to discover who we are and where we come from is at the core of the new 10-part PBS series Finding Your Roots with Henry Louis Gates, Jr., the 12th series from Professor Gates, the Alphonse Fletcher University Professor at Harvard University and director of the W.E.B. Du Bois Institute for African and African American Research. Filmed on location across the United States, the series premieres nationally Sundays, March 25 – May 20 at 8 pm ET on PBS (check local listings).


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