Human history writ large in a single genome

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Stored inside Craig Venter’s genome are clues to the history of humankind, including global migrations and population crashes. Researchers have mined the genomics pioneer’s publicly available DNA sequence, and those of 6 others, to reveal major milestones in human history.


“You can take a single person’s genome and learn an entire population’s history from it,” says David Reich, a geneticist at Harvard Medical School in Boston, Massachusetts, who was not involved in the study. “This is one of the dreams we’ve had as a community.”

The analysis, published today in Nature1, suggests that descendants of the first humans to leave Africa dwindled to little more than 1,000 reproductively active individuals before rebounding. The study also suggests that, contrary to assumptions made from archaeological evidence, these early humans continued to breed with sub-Saharan Africans until as recently as 20,000 years ago.

Geneticists eager to plumb human history have traditionally compared DNA sequences from numerous people around the world to determine how different populations relate to one another and when they might have gone their separate ways. For instance, studies of DNA from maternally inherited cell structures called mitochondria established that all humans can trace their maternal lineage back to one woman — a mitochondrial Eve — who lived in Africa around 200,000 years ago2.

But, just as mitochondria can lead us back to a single woman, parts of a person’s genome inherited from both their mother and father can also be followed back in time, with individual genes traced back to points before any mutations had developed, when just one version — a common ancestor — of that gene existed. Because of the way a person’s maternal and paternal chromosomes shuffle together to create diversity in their sperm or egg cells, some parts of a person’s genome inevitably share common ancestors more recently than other parts.

“Each little piece of the genome has its own unique bit of history and goes to a unique ancestor as you go further and further back,” explains John Novembre, a population geneticist at the University of California, Los Angeles, who was not involved in the study. “As you look at different parts of the genome, you get access to different parts of history.”

 

Written By: Ewen Callaway
continue to source article at nature.com

10 COMMENTS

  1. So many theists misunderstand (either ignorantly or willfully) when biologists talk about “mitochondrial Eve” or “Y-chromosome Adam”.  They seem to think that this proves Genesis – all humans can be traced to one man and woman.  What they don’t realize – and what this article explains – is that for each of the thousands of genes in our genome, there is a different MRCA.  Mitochondrial and Y-chromosome genes are just easier to trace because of their inheritance pattern and rate of mutation.   There may have been population bottlenecks, but no literal Adam or Eve.   

    I know Richard has made this point about genetic MRCAs in some of his books, but it can’t be stressed too much or too often.   I wish the media would point this out as well.  All of the TV documentaries I’ve seen just perpetuate the notion that we all descended from one single woman or one single man at one point in time.  I get really sick of the “Adam” and “Eve” stuff being tossed around all the time.  They could at least use names from other origin mythologies.

  2. @rdfrs-2450c0875078f592248ac8bff24e7337:disqus
    You have to allow for (theo)logical “reasoning” processes! Whilst scientists gather evidence, fundamentalists are only interested in accumulating confirmation of their fairy-tales – and incredulously rejecting anything which conflicts with them, -  via their “filter-specs”.

  3. [On the subject of Adam and Eve] Stephen Fry: “But perhaps, you know, we should believe in Adam and Eve. Geneticists have established that every woman in the world shares a single female ancestor who lived a hundred and fifty thousand years ago. Scientists actually call her Eve, and every man shares a single male ancestor called Adam. It’s also been established, however, that Adam was born eighty thousand years after Eve. So the world before him was one of heavy to industrial-strength lesbianism, one assumes.”

  4.  
    bluebird
    This proves god is a woman…Mother Nature, that is :D

    It does make the Genesis rib-cloning trick a bit of a temporal contortion act!

    Still!   – Nothing that the rosy blinker specs  and (theo)logic cannot handle!

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