Monthly Archives: February 2014

My Ancestors’ Journey Out of Africa

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A few months ago, on a whim, I decided to order the Geno 2.0 kit from National Geographic (the company was offering a discount on the product).  Within a few days, I received my kit in the mail, and on our Monday holiday in November, I started the process.  I probably watch too many cop shows on TV, but I felt like a criminal as I swabbed DNA from the inside of my mouth.  Fortunately, it’s not that hard to do, and the next day, I sent my samples off in the envelope provided.

One has to wait at least six to eight weeks for the DNA analysis to be complete; when I checked a few weeks ago,  my sample was being validated.  Finally, today, I was able to log in to the website and read my results.  Perhaps it’s something innate in human beings — I mean this curiosity about where we come from– but I must say I was thrilled when I saw it confirmed on my laptop that I really am a part of the greatest story ever told.

The Genographic Project is the brainchild of Dr Spencer Wells, a charismatic population geneticist, author, and documentary filmmaker.  Born in 1969 in Marietta, Georgia, he completed his doctorate in biology in 1994, under Richard Lewontin at Harvard University, and subsequently worked with both Luigi Cavalli-Sforza and Walter Bodmer.

Since 2005, he has directed this genome project, undertaken under the auspices of the National Geographic Society and with support from IBM and the Waitt Family Foundation.   Using advanced DNA analysis, Dr Wells and his colleagues have worked with indigenous communities to help answer fundamental questions about where humans originated and how we came to populate the Earth.  If you listen to his Ted talk, you’ll probably want to participate too!

How does this DNA stuff work?  The following explanation is a paraphrase from the website:

Each of us carries DNA that is a combination of genes passed from both our mother and father.  As part of this process, the Y-chromosome is passed directly from father to son, unchanged, from generation to generation down a purely male line. Mitochondrial DNA, on the other hand, is passed from mothers to their children, but only their daughters pass it on to the next generation.

The DNA is passed on unchanged, unless a mutation — a random, naturally occurring, usually harmless change — occurs. The mutation, known as a marker, acts as a beacon; it can be mapped through generations because it will be passed down for thousands of years.

When geneticists identify such a marker, they try to figure out when it first occurred, and in which geographic region of the world.  Each marker is essentially the beginning of a new lineage on the family tree of the human race.  Tracking the lineages provides a picture of how small tribes of modern humans in Africa tens of thousands of years ago diversified and spread to populate the world.

So, what’s my story?  Well, like every other human being, I’m descended from a common East African ancestor who lived around 180,000 years ago (“Mitochondrial Eve”).   After that,

Marker L3 – 67,000 years ago:  My L3 ancestors became the first first modern humans to leave Africa, representing the deepest branches of the tree found outside of that continent.

Marker N – 60,000 years ago:  Haplogroup N comprises one of two groups that were created by the descendants of L3.  It is considered a western Eurasian group, and  almost all of the mitochondrial lineages found in the Near East and Europe descend from N.

Marker R – 55,000 years ago:  Members of this group moved out of the Near East in all directions, north, east, west, and even back south.  In fact,  descendants of this line dominate the European maternal landscape, making up 75 to 95 percent of the lineages there.

Marker R0 – 41,000 years ago:  Oddly enough, this R0 haplogroup is found at highest frequency in Arabia.  My ancestors were probably the ones who migrated east into Central Asia and northwest into Europe.

Marker HV – 22,350 years ago + or – 7,745:  Haplogroup HV is a west Eurasian haplogroup found throughout the Near East, including Anatolia and the Caucasus Mountains of southern Russia and the republic of Georgia.  Go figure.

Marker H – 28,000 years ago:  Today, haplogroup H comprises 40 to 60 percent of the gene pool of most European populations.  However, the age of haplogroup H lineages differs quite substantially between those seen in the West compared with those found in the East.  In Europe, its age is estimated at 10,000 to 15,000 years old.  In Central and East Asia, its age is estimated at around 30,000 years old, meaning my ancestors made it into those areas during some of the earlier migrations out of the Near East.

So H is my most recent haplogroup; here’s a heat map showing frequency of this group:
geno20-map

The next results show my ancestry percentages as compared with nine reference populations:
geno20-results

My first reference population is Chinese, and my second is German.

So what does this mean in my case?

The website says,

We compared your DNA results to the reference populations we currently have in our database and estimated which of these were most similar to you in terms of the genetic markers you carry.  This doesn’t necessarily mean that you belong to these groups or are directly from these regions, but that these groups were a similar genetic match and can be used as a guide to help determine why you have a certain result. Remember, this is a mixture of both recent (past six generations) and ancient patterns established over thousands of years, so you may see surprising regional percentages.

And by the way, the analysis suggests that I have 2.3% Neanderthal genes and 2% Denisovan.

American Regional Dialects

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Soon after it appeared on the New York Times website at the end of December 2013, a dialect quiz generated considerable buzz on social media.  I’m always one step behind whatever goes viral, so I didn’t take the quiz until recently.  Here are my results (the red-orange-yellow colors indicate affinity; the dark hues are the locations where speech is most similar to yours):

my-dialect-map

There are only 25 questions, so the results are amazingly accurate , don’t you think?  I was born and raised in Hawaii and, to date, have lived all of my adult life in Massachusetts (not sure where Yonkers comes into play).  I thought to myself, “Is this some kind of a parlor trick?”  But of course it’s not.  According to author Josh Katz, NY Times graphic editor who developed the quiz:

Most of the questions used in this quiz are based on those in the Harvard Dialect Survey, a linguistics project begun in 2002 by Bert Vaux and Scott Golder.

Concluded in 2003, the original survey used 122 questions administered to 30,788 respondents, which is quite a large database.  As in any statistical sampling, there will be outliers, but that doesn’t detract from its validity for many people.  It’s also important to note that the survey was developed for native speakers of American English.

Coincidentally, the online edition of the Dictionary of American Regional English was released in December.  (Harvard University Press published DARE’s first volume in 1985 and the sixth and final print volume in early 2013.)  The dictionary is a treasure trove for linguists and social scientists, but it’s also a lot of fun for  ordinary citizens.  One might worry that American English is becoming increasingly homogenized, and that we are in danger of losing our regional eccentricities, but recent linguistic fieldwork indicates that this is not happening.  We speak like the people around us, and due to accidents of history and geography, there are numerous aspects of vocabulary and pronunciation which differ from place to place.  The many varieties of regional American English, both past and present, are certainly worth celebrating.  As NPR correspondent Amanda Katz writes:

Such marvelous words [slatchy, vinegarroon] are sprinkled through our national literature; without your own team of roaming lexicographers, there is probably no easier way to browse America’s past ways of living and talking than to read its books. But Dictionary of American Regional English gathers all these terms into one place, together with samples of the voices and stories and songs that gave rise to them. It’s the rare American book whose roots extend not just to one region but to all of them.