PDA

View Full Version : Jefferson's K2 Chromosome Found in Britain



Ĉmeric
Wednesday, February 7th, 2007, 01:15 AM
From the BBC http://news.bbc.co.uk/2/hi/science/nature/6332545.stm

DNA tests carried out on two British men have shed light on a mystery surrounding the ancestry of Thomas Jefferson, America's third president.

In the 1990's, DNA was taken from male relatives of Jefferson to see if he fathered a son with one of his slaves.

They found the president had a rare genetic signature found mainly in the Middle East and Africa, calling into question his claim of Welsh ancestry.

But this DNA type has now been found in two Britons with the Jefferson surname.

Professor Mark Jobling, from the University of Leicester, and colleagues discovered the two British Jeffersons possessed the same rare male (or Y) chromosome type as the third US president.

Genetic analysis showed the British men shared a common ancestor with Thomas Jefferson about 11 generations ago. But neither knew of any family links to the US.

The unusual lineage has not been found in white Britons before. Last month, Professor Jobling's group reported the discovery of seven white men from Yorkshire carrying a West African Y chromosome.

Welsh extraction

The Y chromosome is a package of genetic material passed down from father to son, more or less unchanged - just like a surname.

Over many generations, it does accumulates small changes in its DNA sequence, allowing relationships between different male lineages to be studied.

Y chromosomes can be classified into broad groups (haplogroups) which, to some extent, reflex a person's geographical ancestry.

Certain haplogroups might be common in, for example, East Asia but rare in Europe. In Britain, sharing a surname raises the likelihood of sharing the same Y chromosome.

The two men in the latest study had paternal ancestry in Yorkshire and the West Midlands respectively.

Thomas Jefferson's haplogroup - shared with the two men from Britain - is known as K2.

This discovery scotches any suggestion that Jefferson - who was president between 1801 and 1809 - must have had recent paternal ancestors from the Middle East.

K2 makes up about 7% of the Y chromosome types found in Somalia, Oman, Egypt, and Iraq. It has been found at low frequencies in France, spain, Portugal and Britain.

Of the K2s looked at by the study, Jefferson's Y chromosome was the most similar to that of a man from Egypt. But genetic relationships between differnet K2s are poorly understood, and this may have little significance.

Instead, say the researchers, their study makes Jefferson's claim to be of Welsh extraction much more plausible.

Common ancestor

Professor Jobling told BBC News: "Finding that Jefferson's Y chromosome was one mutation step away from an Egyptian type makes you think 'crikey, could he have relatively recent origin in the Middle East?'

"Our point is that we find, at lower frequencies, French, British and Iberian K2s and they are jolly diverse. He fits into that picture of a west European sub-population of K2s."

The DNA sequences of individual K2s - including those from Europe - are quite different from one another.

This "genetic diversity" has to accumulate over time, supporting the idea that Jefferson's haplogroup is not a recent introduction into Europe.

The haplogroup has probably been present for centuries in the "indigenous" population of western Europe, says Professor Jobling, and is not exclusive to the Middle East or Africa.

Paternity case

It could have been introduced to europe by the first modern humans to colonise the continent 40,000 years ago.

Another theory concerns the Phoenicians, an ancient maritime trading culture that spread out across the Mediterranean from their home in what is now Lebanon. K2 is relatively common in Lebanon, leading to suggestions that European K2s may be descendents of these ancient traders.

In 1998, Jobling and others completed an investigation looking at whether Jefferson, main author of the Declaration of Independence, fahtered a son with Sally Hemings, a slave he owned.

Rumours has long existed that they had one or more children. Since Jefferson had no legitimate surname-bearing progeny, the team used samples from the descendents of his paternal uncle.

They compared these with descendents of Eston Hemings Jefferson, Sally's last son. The Y chromosomes matched, suggesting Jefferson, or one of his paternal relatives, was Eston's father.

Ĉmeric
Tuesday, November 4th, 2008, 04:39 AM
K2 has been relabled T.

Arundel
Thursday, November 20th, 2008, 04:40 AM
That is a very interesting article. I have read a lot about Jefferson in the past. Although he was apparently a brilliant man, I think he was a bit of a hippocrit by pretending to not approve of slavery, when he had many slaves himself. I believe the question of blood lines had come up again recently, wherein Sally's present day descendants had wanted to be buried in the Jefferson Cemetery, which privilege they were denied.
I read many journals and diaries and recently I noticed that an important man of his time had remarked about Jefferson having a negro male that looked just like him. I believe Jefferson's red hair has showed up throughout the Hemings family. I have read that he had several children with Sally and as they matured he just let them drift away from their place of birth. Strange situation all around, but then Sally was a half sister to his dead wife, and she was half white, so perhaps Jefferson did not think of her as being black.

Ĉmeric
Thursday, November 20th, 2008, 08:03 PM
Sally Hemings was a quadroon. She was 1/2 sister to Martha Wayles Jefferson. Though at least one of the paternal lines descended from Sally Hemings has the same Y haplogroup as Jefferson, that does not prove Thomas Jefferson was the father. It could have been Jefferson's brother, Randolph. The possibility that Jefferson may have owned slaves that were fathered by his own father, mulattoes or quadroons with the Jefferson haplogoup, who could have father Sally Hemings children. And it is not known if all of the Hemongs children shared the same father. But I do agree that is was somewhat hypocritical of Jefferson to oppose slavery while at the same time being depended on it - to the extent that slave families were broken up sold apart to pay his debts. George Washington was another individual who owned slaves, yet opposed slavery. Washington freed his slaves in his will but only after the death of his wife Martha. :oanieyes We would have been better off if Jefferson & Washington had advocated the removal of all Negroes from the US at the beginning of the Republic but too many were depended on them for their gracious standrad of living.

Arundel
Wednesday, January 28th, 2009, 04:59 AM
I enjoyed your article, and have a question. I am a dedicated historian & genealogist, & have traced my ancestry back for 11 generations. I have found that about 90% of my ancestors came from England. Even after arriving in America they continued to marry other english descended people. These various families left England in the 1600's. My question is would my genes show a definite English link?
I would like very much to know.
Lately I have been researching records in Weymouth, Dorset, England & learned that ships left Weymouth to fight against the Armada, even capturing a spanish ship & bringing it to harbor in Weymouth. My Gardner ancestors would have been living there at that time. How exciting. I always like to make my genealogy full of history and not just statistics on a page.
Please let me know what you think about my genetic makeup.

Ĉmeric
Wednesday, January 28th, 2009, 05:20 PM
I have found that about 90% of my ancestors came from England. Even after arriving in America they continued to marry other english descended people. These various families left England in the 1600's. My question is would my genes show a definite English link?
I would like very much to know.

What is the other 10% of your ancestry? Your genes should show a definitely English link. The English themselves have changed over the last 400-years, with Huguenot refugees - I think around 50,000 at a time when England's population was around 5-million - coming to England & later Scots & Irish during the industrial revolution. There are probably several old Yankee or Southern families that are who more closely resemble the 17th century English (genetically, genealogically) then the current English. And I'm not refering to the "New British" who've arrived in the last 60-years.

Dreyrithoka
Wednesday, January 28th, 2009, 06:14 PM
I think he was a bit of a hippocrit by pretending to not approve of slavery, when he had many slaves himself.

Such a thing was relatively common (http://www.nas.com/~lopresti/ps.htm) for US presidents, and even happened post-Lincoln in one confirmable instance, although I certainly agree that in Jefferson's case at least it was certainly rather hypocritical.