The Genetic Genealogist

Adding DNA to the Genealogist's Toolbox

Archive for May, 2007


The DNA Network

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The Genetic Genealogist has been invited to be a member of the new genetics blogging group The DNA Network, founded by Rick Vidal of My Biotech Life and Hsien Lei of Eye on DNA. The group is “a network (double helix?) composed of life science enthusiasts with specialized views in areas such as genetics, biology, biotechnology, health care, and much more.”

Not only is the network a great way to discover new blogs, but it is an opportunity to stay current on events and developments in the field of genetics. The following blogs are currently members of the network:

My Biotech Life
DNA Direct Talk
Epidemix
Epigenetics News
evolgen
Eye on DNA
Gene Sherpas: Personalized Medicine and You
Genomicron
henry: the human evolution news relay (genetics)
Mary Meets Dolly
Microarray and Bioinformatics
Omics! Omics!
ScienceRoll
And me, The Genetic Genealogist.

If you’d like to subscribe, the feed is available here.

Famous DNA Review, Part I – Thomas Jefferson

Thomas Jefferson, 3rd President of the United States, has been at the center of a DNA controversy for over 200 years. In September 1802 journalist James T. Callender wrote in Richmond Reporter that Jefferson had for many years “kept, as his concubine, one of his slaves. Her name is Sally [Hemmings]. The name of her eldest son is Tom. His features are said to bear a striking though sable resemblance to those of the president himself.” Although these rumors had reportedly already been passed around quietly, this article spread the rumor far and wide, setting off many years of debate.

In 1998 analysis of a male descendant of Jefferson’s paternal uncle showed that Jefferson’ Y chromosome belonged to haplogroup K2 (Thomas Jefferson did not have any male descendants to provide DNA. For more information, see: “Jefferson fathered slave’s last child.” 1998. Nature 396 (6706): 27–28. PMID 9817200). Haplogroup K2 is rather rare, constituting just 1% of worldwide Y chromosomes (See “Thomas Jefferson’s Y chromosome belongs to a rare European lineage.” Am J Phys Anthropol 132(4): 584-9. PMID 17274013 ). Surprisingly, or perhaps not-so-surprisingly depending on which side of the debate you stood, a male descendant of Sally named Easton Hemmings possessed the same K2 chromosome, suggesting a genetic link between Jefferson and Easton. Keep in mind, however, that this is not determinative since it is possible that any of Jefferson’s male relatives (who possessed the same Y chromosome) could have fathered Easton. And keeping in mind that non-paternal events are ALWAYS a possibility, nothing is 100% certain. Not until we can time-travel and obtain DNA samples from the source!

To see Jefferson’s genetic profile or to compare it to your own, it is available on Y-Search Q8UXG .

DYS19 – 15
DYS388 – 12
DYS389I – 12
DYS389II-I – 15
DYS390 – 24
DYS391 – 10
DYS392 – 15
DYS434 – 11
DYS435 – 11
DYS436 – 12
DYS437 – 14
DYS438 – 9
DYS439 – 12
DYS460 – 10
DYS461 – 11
DYS462 – 13

What do all those numbers mean? They are Short Tandem Repeats (STRs), informational markers that are measured by the number of times a certain sequence repeats. DYS390, for example, is composed of a the repetitive sequence [TCTG]8 [TCTA]11[TCTG]1[TCTA]4. I match Jefferson at four loci – how does your DNA match up with Jefferson’s?

Are aboriginal Australians and New Guineans the modern-day descendants of the extinct species Homo erectus?

Some scientists have hypothesized that Australian aboriginals received a portion of their DNA from an ancient hominid species called Homo erectus, which for a short time was contemporaneous with modern man. A recent study published in PNAS (Proceedings of the National Academy of the Sciences) set out to answer this question by analyzing mtDNA and Y-chromosome samples from aboriginals.

A total of 172 mtDNA and 522 Y-chromosome previously published and new sequences from aboriginal Australians and New Guineans were analyzed for mtDNA and Y-chromosome variation and were compared to the current world haplogroup tree. All of the mtDNA sequences were members of the M and N founder branches, and all of the Y-chromosome sequences fell into the C and F founder branches.

The results suggest that the Australian aboriginals are descendants of the same emigrant group that left Africa 50,000 to 70,000 years ago and populated Europe and Asia. At least from the small number of samples analyzed for this study, there does not seem to be any DNA contribution from Homo erectus.

The uniformity of the sequences suggests that once humans migrated into the region there was little other gene flow. This might explain why the Australian and New Guinean populations share phenotypic features that are unique to the region.

You can read more about this new study at National Geographic or NewScientist, or read the article online for free at PNAS. Additionally, Ron Scott at Scott Genealogy has provided a transcript (pdf) of an interview with Toomas Kivisild (one of the authors of the study and a name that many genetic genealogists will recognize).

Big News for Both Genealogists and Archivists

FamilySearch (a nonprofit organization sponsored by The Church of Jesus Christ of Latter-day Saints) announced today that it will provide FREE services to any and all archives and records custodians who wish to digitize, index, publish, and preserve their collections. This is, of course, on top of the ambitious project already underway to digitize and make freely available the 2 million rolls of microfilm stored in the Granite Mountain Records Vault.

This is a huge benefit for genealogists, since many more records will be freely available online. This is also a huge benefit for archivists and record depositories, since they can digitize and make available their collections for free using FamilySearch’s many years of scanning experience.

Thanks to Dick Eastman and Miriam Midkiff for sharing this information (which seems to have been released via email, but still isn’t available at their website).

A New Design

I spent the morning doing a redesign of the blog.  I should have been studying, but I’ve been meaning to give the site a new look for a while now.  My goals were (1) to make the content the center of attention; (2) to quickly and easily provide information about the blog and subscription options to newcomers; (3) to minimize the impact of advertising (since I don’t make that much anyway!); and (4) to make the site more visually pleasing and professional.  If you have any problems accessing information or using the site, please be sure to let me know.  If you like the new design, let me know that too!

Ask a Geneticist

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Do you have a burning question about genetics that’s been keeping you up at night? Ever wonder why the combination of red hair and brown eyes is so rare? There are two great resources currently available online for anyone who is curious about genetics.

AsktheGeneticist is a partnership between the Department of Human Genetics at Emory University and the Department of Genetics at the University of Alabama at Birmingham. The mission of AsktheGeneticist “is to answer questions about genetic concepts, and the etiology, treatment, research, testing, and predisposition to genetic disorders.” AsktheGeneticist has a genetic genealogy section, but it’s pretty sparse.

The Tech Museum of Innovation in San Jose, California has partnered with the Department of Genetics at Stanford University to present “Genetics: Technology with a Twist.” The interactive site has an ‘Ask The Geneticist’ section where you can ask a Stanford geneticist a question.

The site also has an interactive eye calculator you can use to predict the color of your child’s eyes (for fun, of course). For example, both my wife and I have brown eyes, but both our mothers have blue eyes. According to the calculator (which takes other factors into account), our child had a 75% chance of have brown eyes, 10.9% green, and 14.0% blue. Note that these percentages suggest that he might have had a 0.1% chance of no eye color (just kidding, of course!). Our son, against the odds, has blue eyes.

Although these websites could be both entertaining and a great source of information, I don’t recommend their use for the diagnosis or treatment of any type of genetic disorder.

Top 5 Reasons to Save Your Grandmother’s DNA

1. You got those big blue eyes from your grandmother, but chances are you inherited less desirable genes as well. We inherit our DNA from our parents, who inherited it from their parents. Since we all possess genes that can cause or contribute to disease, knowing one’s DNA and family medical history can be a great resource for someone who learns they have a genetic disorder.

2. Full genome sequencing is right around the corner! The X-prize quest for the $1000 genome will lead to efficient and affordable whole-genome sequencing. As commercial companies crop up and compete for customer’s business, leading to even lower prices.

3. Your grandmother’s DNA contains clues to her ancestry. X-chromosome, mtDNA, and autosomal genealogy tests contain clues to a person’s ancestry, both recent and ancient.

4. Even if you aren’t interested in this whole genetic genealogy craze, somebody you know will be! Genealogy is one of the most popular hobbies in America, and the use of DNA to augment traditional genealogical research is growing faster than ever. Chances are that someone you know will someday be interested in your grandmother’s DNA!

5. All the undiscovered possibilities. No one knows what uses will be discovered for DNA in the future. Save that DNA just in case!

Disclaimer: Some people are very uncomfortable with the thought of gathering and storing a loved one’s DNA, and those beliefs should be honored and respected. It is ALWAYS best to obtain your grandmother’s permission before you gather her DNA. So don’t delay, call her now!

This is a contribution to Problogger’s Top 5 Project.

Busy Week at The Genetic Genealogist

I just wanted to let my readers know that posting will be on the light side this week because of exams.   I am finishing up my first year of law school, so Constitutional law and Property are taking up most of my time.  And stay tuned, I have some big projects in the works for the very near future!

Can Scientists Have a Sense of Humor?

Scienceroll just posted a hilarious video called the “DNA-ting Game“, an advertisement for Caliper Life Sciences which is a spoof on 1970′s “The Dating Game.” If you think science humor is funny, you’ll love this video. I highly recommend you go check it out. For a little background information, they talking about analyzing DNA samples using gel electrophoresis. The video is actually an elaborate advertisement for an alternative to electorphoresis.

There are some other funny videos I’ve seen as well, including the great advertising campaign from Biocompare. There are three commercials – here, here, and here. They’re another example of biotechnology companies jumping into this field of advertising. In our lab we typically made decisions based on price, but who knows what effect appealing to our sense of humor might have?

Native American DNA in England

I was very surprised when genetic testing revealed that my maternal lineage was not European. I’m sure, however, that my surprise was nothing compared to that of two British women who recently discovered that their maternal lineage was of Native American descent (the original article is available through the BBC).

Doreen Isherwood and Anne Hall learned that their mtDNA belonged to Haplogroups A and C, traditional Native American Haplogroups. As the BBC story explains, Native Americans were brought back to England as early as the 1500s.

Said Ms. Hall: “I was thrilled to bits. It was a very pleasant surprise. To have Native American blood is very exotic.”

Thanks to The Genealogue.