New analytical techniques have been brought to bear on Thomas Jefferson’s Y chromosome, in a study to be reported in the April issue of the American Journal of Physical Anthropology.
The presidential chromosome turns out to belong to a rare class called ‘K2’, which is found at its highest frequency in the Middle East and Eastern Africa, including Oman, Somalia and Iraq.
Its closest match was in a man from Egypt. Does this mean that the President had recent ancestry in the Middle East? A careful survey revealed a few K2 chromosomes in France, Spain and England. Together, the K2s form a diverse group that may, in fact, have been in western Europe for many thousands of years.
Almost ten years ago, researchers at the University of Leicester, including Mark Jobling, working with international collaborators showed that Thomas Jefferson fathered at least one of the sons of Sally Hemings, a slave of Jefferson’s.
The work was done using the Y chromosome, a male-specific part of our DNA that passes down from father to son. Jefferson carried a very unusual Y chromosome type, which helped to strengthen the evidence in the historical paternity case.
New evidence ties Jefferson to two of 85 randomly recruited men in England who have the surnname Jefferson. They surprisingly share exactly the same Y chromosome as the President despite know historical connection between their families and the USA. The two are probably separated by about 11 generations, Jobling explains.
The ultimate origins of K2 chromosomes remain a mystery, however, and need further investigation. They may have been present in Europe since the Stone Age but could have arrived with the Phoenicians from what is modern-day Lebanon.
Adapted from U of Leicester Press Release