The Results are shown in chart form on the "DNA Results" page. Similar results are grouped together, and mutations are noted by color coding.

Most Thompson families in our project originated in the British Isles. Most of the information below is dated, we have many new lines to consider. Know that the "T" designation only refers to the researcher initial, not an official "Thompson/Thomson classification. 

The best matches in the Thompson family (so far) are discussed below. There are several other possible matches, which should be evaluated by test upgrades and by the submission of pedigrees to our Patriarchs page. If you are in a position to donate to the group fund please do.

T-2 and T-8 share a common ancestor in a Scots-Irish Thompson family. Genealogy has been traced from America to Ireland then to Scotland. The Most Recent Common Ancestor of T-2 and T-8 is Matthew Thompson b. c1720-1725 in Co. Donegal, Ireland [part of Ulster]. Matthew emigrated to America and lived in Lancaster County, Pennsylvania, then Augusta County, Virginia before moving to South Carolina about 1772-1773 (based on deeds in VA and SC). This is a typical Colonial-era Scots-Irish migration path. T-2 is descended from Mathew's son William, and T-8 is descended from Matthew's son James. To find the estimated time to the Most Recent Common Ancestor, we can use the Family Tree DNA Time Predictor (FTDNA TiP). This tool compares the 35/37 match and predicts that the probability that T-2 and T-8 shared a common ancestor within the last 100 years is 30%, within the last 200 years is 70%, and within the last 300 years is 89.97%. These probabilities take into consideration the mutation rates for each individual marker being compared. The tool proves to be quite accurate since we know from genealogical records that the Most Recent Common Ancestor was born about 280 years ago, and his sons were born about 225 years ago. We welcome other men from this lineage to test, especially any who might remain in Ireland. T-2 and T-8 are in the C haplogroup, which is anciently Asian. T-8 has had a SNP test confirming this, and T-2's haplogroup assignment was confirmed by a deep SNP test. Both men may learn more in the next few years from the National Geographic Genographic Project about the migration of the C haplogroup.

T-45 and T-68 are descended from Richard Thompson who was born in 1528 in either England or Scotland [the pedigrees disagree on the birth place]. This is another extraordinary match, because these two men do not share a common ancestor for at least eight generations. Their Most Recent Common Ancestor is William Thompson, b. 1742 MA, who married Lydia Dyer, so he shared their Y-chromosome markers. To confirm the pedigree for earlier generations, descendants from other lines of William Thompson, b. 1713 MA, m. Mehitable Hillard; Benjamin Thompson, b. 1684 MA, d. 1750, m. Sarah Aldrich; John Thompson Jr., b. 1642 MA, d. 1739, m. Thankful Woodland; John Thompson, b. 1618/19 England, d. 1685, MA, m. Sarah Woodman; David Thompson, b. c1592, d. 1628 England m. Amyes Colle; Richard Thompson Jr., b. c1555, d. 1603 England, m. Florence Cromlan; and Richard Thompson b. 1528 should test.

T-15 and T-51 share a common ancestor. This match is the result of advertising for descendants to be tested of Thompsons from North Gwillimbury, Ontario. The advertisements were placed in genealogical society publications. The Most Recent Common Ancestor of T-15 and T-51 is John Thompson, b 1736 in Connecticut. T-51 should consider an upgrade to verify the match. Genealogical research is ongoing. Males from other lines of this family should be tested.

T-30 and T-31 are descendants of David Thompson b 1766 in Windsor, Connecticut. Their Most Recent Common Ancestor is David's son Isaac Thompson who was born about 1810. The 25-marker results of T-30 and T-31 show only a one-step-mutation difference, so Isaac had one of these two genetic profiles. David should have had the same genetic profile, but this will not be known until a match is found from a descendant of one of David's other sons.

Genealogical research shows that T-26, T-21, T-22, and T-19 share a common ancestor. Their Most Recent Common Ancestor is George Thompson (b. 1705) who married Catherine Phillips. T-26, T-21, and T-22 are descended from George's son John Thompson but T-26, T-21, and T-22 are very closely related. Their Most Recent Common Ancestor is several generations removed from their ancestor John Thompson, so no conclusions can be drawn from their results about the genetic profile of the ancestor. T-19 is descended from George's son William. He does not match the other group closely enough to determine their ancestor's genetic profile. More male descendants of George Thompson (b. c1670) are needed for testing.

T-65 and T-67 share a common ancestor. They should research the records of Hampshire and Frederick Counties, Virginia.

T-12 and T-52 share a common ancestor. This is an extremely close match, and the ancestors of both men were in North Carolina in the 1700s. T-52 should search the records of Duplin and Bladen Counties, North Carolina for any mention of Alexander Thompson.

T-42, T-88, and T-25 share a common ancestor. The Most Recent Common Ancestor of T-42 and T-88 is Electious Thompson, b. 1755 in Prince George's Co., Maryland. T-25 should submit his pedigree to our Patriarchs Page so that we may be able to more closely determine when his ancestry ties in with the line of Electious Thompson.

DNA results are only useful when used in conjunction with traditional historical and genealogical research.