"My guess is that the Y chromosome of every living man has spent at least one generation in the testis of a warlord," the Oxford geneticist Bryan Sykes once told The New York Times. One sexually prolific warlord in particular was Genghis Khan, whose Y chromosome is now found in 16 million men in Central Asia. How did that happen? When Khan would conquer a territory, Sykes says, "he killed the men and systematically inseminated the most attractive women."
That is sexual selection on a grand scale, and that is the subject that most interests Sykes, who famously linked modern humans back to common female ancestors in his bestselling book The Seven Daughters of Eve. A subsequent book, Adam's Curse, argued that the male of the human species will become extinct within 5,000 generations. Now Sykes has turned his attention to one of the most genetically interesting places in the world -- the United States, which is the subject of Sykes's new book DNA USA: A Genetics Biography of America.
Sykes tells Big Think he set out, Easy Rider-style, to find the ways in which people with African, Native American and European ancestry were linked. The results were often quite surprising. For instance, most African Americans have some European DNA.
This raises an interesting question. What does it mean about your identity when you discover that you are related to another group that you never would have suspected? The truth is simply too disturbing for some people who simply don't want to know. And that is why Sykes has been described as "de Tocqueville with a DNA kit." Sykes, an Englishman, is teaching Americans about who they are.
That is one of the most significant applications of genetics, but its uses certainly don't end there. Big Think asked Sykes to explain the one thing everyone needs to know about genetics. It turns out he gave us two.
Watch the video here:
What's the Significance?
According to Sykes, it is too deterministic to say "your genes determine everything you do." But they are "the deck of cards you are dealt at birth." It is your choice as to what to do with those cards. And yet, the DNA that you are made up of does come from somewhere.
While some are not so happy to find out where they came from, Sykes says "I’m very proud of all of my ancestors that have got their DNA through to me, and I think everybody should be, particularly in America. Because all of you have ancestors that took a lot of trouble to get here, whether it was across the frozen wastes of Siberia or more recently on ships from Europe or, unfortunately, ships from Africa against your ancestors’ will."
Of course, genetics doesn't just tell us about the past. It can also help us predict the future. There are major benefits in health care that derive from knowing your genetics.
What do you think?
As science and health care would greatly benefit from possessing everyone's DNA in a database, do you have a moral responsibility to cooperate and share yours?
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