Notes:

The top of this tree is now tentatively identified as 1690 Francis Wright. This is from the work of Robert N. Grant who presents circumstantial evidence that 1690 Francis Wright was the grandfather of John Wright, carpenter, of Goochland Co., VA and 1767 Francis Wright. Mr. Grant has uncovered documents that show 1690 Francis had a son named Francis who married Anne (___) and had sons John and Francis. The time and location fit well, but documents proving the relationship have not yet been found. The dashed lines indicate these links are based on circumstantial evidence. What is known, from these Y-DNA analyses, is that both lines share a common ancestor.

Currently, there are results from six Y-DNA samples in this line; five report 37 markers and the other 25 markers. The pattern is distinct from the other Wright DNA results with a haplogroup of R1a, and the "double 10" at DYS 388 and 439. That is an uncommon combination.

The only mutations that have occured are in DYS 389-2 and DYS 570. The different lines reflected by these mutations are color-coded. Since it is not yet known in which generation the mutation occured, the entire line is shown in that color. The total number of conceptual events represented by these samples is 46, assuming 1690 Francis is the common ancestor.

Generations:

Assuming 1690 Francis Wright is the common ancestor, there are 9 generations between him and Samples B, D, or F, and 10 generations from him to Samples A or E.

There are different ways to calculate the number of years in a generation. One is to count the number of years between the father (or mother) and son from their birth dates. Another method is to count the difference between the average age of the father at the birth of all his children to the average age of the son at the birth of his children. When comparing these methods for Line A, the results were similar (30.1 vs. 30.6 years). Since some data on birth dates are missing from my records, I chose to use the first method until more data are available. FTDNA uses an average generation of 25 years. The Mumma study found an average generation time span of 33 years, and cites a paper supporting an average of 34.4 years. The average of our six lines is 31.3 years. The mean generation in years for each of the lines is shown in this table:

Mutation Rate:

FTDNA has determined that each marker differs in the rate of mutation. The average rate is 0.00399 for the first 12 markers, 0.00481 for markers 13 through 25, and 0.00748 for the markers 26 through 37. FTDNA has not yet published the estimated rates for each individual marker. The overall mutation rate, when looking at our reported markers (37*39 + 25*7 = 1618) for 46 conceptual events is 5/1618 or 0.00309; which is within the range of the expected rate.

Estimated Time to Most Recent Common Ancestor:

Knowing the mutation rate and the number of markers is key to calculating the estimated time to the common ancestor. There are several sources available to perform this calculation. First, this was done using the calculator provider by Ann Turner. Sample B (chosen because he presently represents the modal haplotype) compared to Sample E (chosen because he is from the comparison branch) shows 37 markers for 18 conceptual events, and a 1-step mismatch. This gives a mutation rate of 1/(37*18) = 0.0015. Using Ann's calculator, this yields a mean of 15.3 generations to the common ancestor or about 479 years ago (assuming 31.3 years/generation).

Dean McGee has published a very useful Y-DNA Comparison Utility that will refine this estimate further by using a different mutation rate for the three groups of markers. The common ancestor was about 403 years ago comparing Sample B to Sample E using this utility. This was based on these assumptions: a) the 95% probability level, b) an average generation of 31 years, and c) the infinite alleles mutation model.

FTDNA has recently made available another utility called the Family Tree DNA Time Predictor. This program uses a calculation that considers the individual mutation rate of each marker. It does not allow the user to modify from their standard 25 years per generation. When using this program to compare Sample B to E, the result shows a 97.48% probability that these lines shared a common ancestor within 300 years.

It is believed that 1690 Francis Wright was born before 1653. There is documentary evidence that there was not a common ancestor since 1711 for Samples B and E. These results are consistent (with reasonable certainty) with 1690 Francis Wright being the most recent common ancestor.

Tests from descendants of other Wright lines dating to the early 1700's in the Northern Neck of Virginia (there were not very many) could eliminate other possible common ancestors, or confirm that other lines are related. Additional samples from descendants from other branches might also help to further pinpoint the timeframe of the common ancestor.

Return to Tree:

Return to Wright DNA Project:

Last Update:
07/05/2005
Jeffrey A. Wright