Upcoming holidays likely mean time spent eating and talking with rarely seen relatives - something that could be considered a boon or a trial. One thing I enjoy, however, is the opportunity to learn more about my family history and ancestry through discussions with older family members.
Now, research conducted by Stanford geneticists Carlos Bustamante, PhD, and Andres Moreno-Estrada, MD, PhD, has shown that we carry a surprising amount of similar information in our genes. The strands of DNA include information not just about who our parents, grandparents and great grandparents were, but also about how they mingled with other population groups throughout history. And they did so by studying one of the biggest melting pots of recent past: the Caribbean. The research, conducted in collaboration with Eden Martin, PhD, from the University of Miami, was published today in PLoS Genetics.
As described in our release:
The researchers compared patterns of genetic variation found in populations in and around the Caribbean, which has had a particularly tumultuous past since Christopher Columbus stumbled into the Bahamas in 1492. Not only did they identify an influx of European genes into the native population that occurred within a generation of Columbus’ arrival, but they also discovered two geographically distinct pulses of African immigration that correspond to the beginning and height of the transatlantic slave trade.
The study demonstrates how deciphering genetic echoes from the distant past can illuminate human history. But it also helps explain why some populations, like Latinos, who may be classified by medical researchers as a single group, display marked differences among populations in susceptibility to diseases or responses to therapeutic drugs.
If you're into history, the findings are fascinating. For example, the research shows that the Caribbean islands were first populated about 2,500 years ago by people from inland South America, and it indicates that the European component of the Caribbean gene pool was likely contributed by relatively few individuals who settled in the islands (subsequent waves of European immigrants came primarily to the mainland of the Americas). But geneticists and clinicians are also paying close attention to studies such as these. As Moreno-Estrada told me:
All this affects what we call a genetic-mapping strategy to identify disease variants specific to population subgroups. For example, those individuals with more European influence may be at increased risk for certain diseases because that genetic contribution was made by only a few individuals. Or, perhaps Caribbeans with more African ancestry may share an increased risk of diseases with others from West Africa. We’re not yet at the point where we are able to say which populations are most likely to have specific diseases, but now we can begin to figure out the important components.
Previously: On the hunt for ancient DNA, Stanford researchers improve the odds, Stanford study investigates our most recent common ancestors and Recent shared ancestry between Southern Europe and North Africa identified by Stanford researchers
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