John Jefferson, 52, of Norrisville, Pa., said he was not particularly surprised at the news that he was a descendant  of President Jefferson and his slave, Sally Hemings. "I've known it practically all of my life."

            By DINITIA SMITH and NICHOLAS WADE

               DNA tests performed on the descendants of Thomas Jefferson's family and of Jefferson's young
               slave, Sally Hemings, offer compelling new evidence that the third president of the United
          States fathered at least one of her children as has long been speculated, according to an article in the
          next issue of the scientific journal Nature.

          The report is based on blood samples collected by Eugene A. Foster, a retired pathologist who lives
          in Charlottesville, Va. The finding undercuts the position of historians who have long said that
          Jefferson did not have a liaison with the slave some 28 years his junior and confirms, but with a
          surprising twist, the oral tradition that has been handed down among Sally Hemings' descendants.

          The new evidence is likely to send historians scurrying to re-evaluate Jefferson, particularly his role in
          the anti-slavery movement. It may also have a wider resonance. The accusation of an affair with
          Hemings, one of several charges considered in a mock impeachment trial staged by the
          Massachusetts state Legislature in 1805, was indirectly denied by Jefferson.

          "Now, with impeccable timing," the historian Joseph Ellis and the geneticist Eric Lander write in a
          joint commentary on the new report, "Jefferson reappears to remind us of a truth that should be
          self-evident. Our heroes -- and especially presidents -- are not gods or saints, but flesh-and-blood
          humans."

          Foster's finding rests on analysis of the Y chromosome, an unusual genetic component because,
          except at its very tips, it escapes the shuffling of the genetic material that occurs between every
          generation. The only changes on the Y chromosome are rare sporadic mutations in the DNA that
          accumulate slowly over centuries. Male lineages can therefore be distinguished from one another
          through the characteristic set of mutations carried in their Y chromosomes.

          Foster said he began his research almost on a whim, at a friend's suggestion. He soon grew more
          serious, and with the help of many colleagues, has tracked down four male lineages that bear on the
          paternity of Sally Hemings' children. They are Jefferson's lineage, derived from his paternal
          grandfather; the lineages of Tom Woodson and Eston Hemings Jefferson, Sally Hemings' oldest and
          youngest sons; and the lineage of the Carrs, two of Jefferson's nephews on his sister's side.

          Sally Hemings had other children, but they left no surviving male heirs. The Carrs come into the
          picture because of the story spread by Jefferson's heirs that one or the other of the nephews fathered
          Hemings' children, explaining their pronounced resemblance to the Jeffersons.

          Foster's samples were analyzed by Christopher Tyler-Smith, a population geneticist at the University
          of Oxford in England, and his colleagues. They found that the Jeffersonian Y chromosome had a
          distinctive set of mutations, unmatched in any of 1,200, mostly European, men who were analyzed
          by the same method.

          The set of mutations on the Y chromosomes of three descendants of John Carr were almost identical
          to one another and different from the Jeffersonian chromosome, ruling out the Carrs as possible
          fathers.

          The Y chromosome of a descendant of Eston Hemings Jefferson made a perfect match to
          Jefferson's, but those of five descendants of Thomas Woodson were completely different.

          "The simplest and most probable explanations" for the findings, Foster and colleagues report, "are
          that Thomas Jefferson, rather than one of the Carr brothers, was the father of Eston Hemings
          Jefferson, and that Thomas Woodson was not Thomas Jefferson's son."

          Lander, a DNA expert at the Whitehead Institute in Boston, said Foster's evidence showed there
          was a less than 1 percent chance that a person chosen at random would share the same set of Y
          chromosome mutations that exist in the Jefferson lineage.

          "The fact that Eston Hemings' descendant has this rare chromosome, together with the historical
          evidence, seals the case that Jefferson fathered Eston," Lander said.

          The evidence that Thomas Woodson was not Jefferson's son is surprising, Foster said, because of
          the particularly strong oral tradition that has come down independently in the five lines of the
          Woodson family. Woodson, born shortly after Jefferson's return from his service as minister in Paris,
          was 12 when James Callender, a journalist, published accusations in a Richmond newspaper that
          Jefferson was Hemings' lover. Shortly afterward, Woodson was sent off to live with a relative.

          One of the blood samples in the study was taken from John Jefferson, 52, of Norrisville, Pa., who is
          believed to be a direct descendant of Hemings through Eston Hemings Jefferson. John Jefferson's Y
          chromosome matched blood samples taken from the lineal descendants of Jefferson's uncle, Field
          Jefferson.

          In a telephone interview, Jefferson said he was not particularly surprised at the news that he was
          descended from a president and his slave. "I've known it practically all my life," said Jefferson, who
          is disabled and does not work. "I guess I was happy about it, but not really surprised since I've
          believed it all along."

          Jefferson's sister, Julia Jefferson Westerinen, 64, had a more ebullient reaction. "Isn't that wild," said
          Ms. Westerinen, who lives on Staten Island and sells furniture and office equipment to architects and
          corporations.

          "I've known for about 15 years, but I thought I was related to Jefferson's nephew," she said.

          Robert Gillespie, a lawyer in Richmond who is the head of the Monticello Association, which
          includes the descendants of Jefferson's two daughters, said, "We've always agreed with mainstream
          historians that Jefferson wouldn't have fathered Sally Hemings' children." But, Gillespie said, the
          DNA results are "changing my attitude."

          Gillespie said he had always believed that "Jefferson would have shown the second set of children
          love and affection just as he did the first set. Apparently he was a product of the 18th century, and
          had a double standard."

          Ellis, author of "American Sphinx: The Character of Thomas Jefferson," (Knopf, 1997), and other
          Jefferson scholars like Dumas Malone have long said that Jefferson did not have a relationship with
          Hemings. Ellis once dismissed the possibility as "a tin can tied to Jefferson's reputation."

          Now, he said, the DNA tests have changed his mind. "This evidence is new evidence and it seems to
          me to be clinching," he said. Ellis said circumstantial evidence, including a quotation attributed to
          another of Hemings' sons, James Madison, also pointed to a liaison. "It includes the timing of her
          pregnancies, the physical resemblance of her children to Jefferson and Madison saying late in life that
          his mother told him."

          Well before Y chromosome testing entered the picture, a minority of historians were asserting that
          Jefferson had the affair, notably Fawn Brodie, in her book "Thomas Jefferson: An Intimate History."
          Another scholar, Annette Gordon-Reed, an associate professor of law at New York Law School
          and author of "Thomas Jefferson and Sally Hemings: An American Controversy" (University Press of
          Virginia), said she felt vindicated by the DNA tests. "If people had accepted this story, he would
          never have become an icon," Professor Gordon-Reed said. "All these historians did him a favor until
          we could get past our primitive racism. I don't think he would have been on Mount Rushmore or on
          the nickel. The personification of America can't live 38 years with a black woman."

          The new DNA evidence is likely to renew questions about Jefferson's position on slavery, Lander
          and Ellis believe. "Jefferson's stated reservations about ending slavery included a fear that
          emancipation would lead to racial mixing and amalgamation," they wrote in their commentary in
          Nature. "His own interracial affair now personalizes this issue, while adding a dimension of
          hypocrisy."

          Sally Hemings, who was born in 1772 or 1773, was the illegitimate half-sister of Jefferson's wife,
          Martha, the offspring of a relationship between John Wayles and Elizabeth (Betty) Hemings, a slave.
          Sally became Jefferson's property when he inherited the Wayles estate in 1774, and arrived at
          Monticello as a little girl in 1776. She was later described by one of Jefferson's slaves, Isaac
          Jefferson, as "mighty near white . . . very handsome, long straight hair down her back." Jefferson's
          grandson, Thomas Jefferson Randolph, described her as "light colored and decidedly good looking."

          In her early childhood, Hemings probably acted as a "nurse" to Jefferson's daughter, Mary, a custom
          in slave culture. Then in 1787, Jefferson, a widower, who was then the U.S. ambassador to France,
          summoned his daughter Maria to live with him. Maria was accompanied by her young attendant,
          Sally, who was then about 13. Sally's son Madison, who was born in 1805, at the end of his life said
          that his mother became Jefferson's "concubine" in Paris.

          In 1789, Sally Hemings returned with the Jefferson family to Virginia. By then, Sally was 16 or 17,
          and pregnant, according to Madison Jefferson.

          Her first child, Thomas, who the new studies say was not genetically linked to Jefferson, was born
          soon after her return.

          Jefferson's grandson, Thomas Jefferson Randolph, said later that the boy looked like Thomas
          Jefferson. "At some distance or in the dusk the slave, dressed in the same way, might have been
          mistaken for Mr. Jefferson," he said.

          The evidence of Jefferson's relationship with Hemings will only add to a re-evaluation of Jefferson
          that has been going on among historians for some time, Ellis said. "The take on Jefferson for 30 years
          or so has become more and more critical," he said. "Increasingly, he is a window in which race and
          slavery are the panes."

          Jefferson, as portrayed by Ellis and others, was an ambivalent figure. "He plays hide and seek within
          himself," Ellis said.

          But most Americans, he predicted, would have a kinder reaction to what he called "the
          longest-running mini-series in American history."

          "Within the larger world," Ellis said, "the dominant response will be Jefferson is more human, to
          regard this as evidence of his frailties, frailties that seem more like us. The urge to regard him as an
          American icon will overwhelm any desire to take him off his pedestal."