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FTDNATiP now available for ALL customers
Information taken from Facts & Genes from Family Tree DNA
December 31, 2004 Volume 3, Issue 7 & 8

Customers will find the FTDNATiP icon when you click on the Y-DNA Matches selection on your Personal Page. To the right of each person on your Y-DNA Matches Page, for whom FTDNATiP is available, you will find the FTDNATiP icon.

If you are a member of a Surname Project, the FTDNATiP icon will appear for all matches who are members of your Surname Project. If you have any matches outside your Surname Project, the FTDNATiP icon will appear for matches at 25 Markers and 37 Markers.

If you are not a member of a Surname Project, the the FTDNATiP icon will appear for matches at 25 Markers and 37 Markers.

FTDNATiP does a calculation for two individual to determine the time to their most recent common ancestor. The calculation uses the individual Marker mutation rates. The result is presented in an easy to understand format, showing the probability for each hundred year period.

FTDNATiP is a proprietary algorithm developed by Family Tree DNA in conjunction with our Advisory Board Member, Dr. Bruce Walsh, a leading population geneticist.

The calculation by FTDNATiP utilizes the Y DNA results of two persons, and the individual Marker mutation rates. The individual Marker mutation rates used are a result of the study by the University of Arizona which was announced at the 1st International Conference on Genetic Genealogy, on October 30, 2004.

Documented evidence can also be input into the calculations, by entering the number of generations known that the common ancestor did "not" occur. This option is not available for exact matches, since the result of the calculation would not change.

FamilyTreeDNA is the only vendor to provide this powerful tool to the genealogy community.

FTDNATiP has several important benefits. The calculation comparing two individuals will provide probabilities for each 100 year period for the common ancestor. This information will help participants understand when the common ancestor most likely occurred between themselves and a person they match or closely match. In addition, the probabilities can influence or determine if you pursue a match. A third benefit is that FTDNATiP can be used to make the decision as to whether you should pursue a paper trail connection between the ancestors of two people who are a close match. A fourth benefit would be to identify branches of the family tree that are connected incorrectly.

Different pairs of people with the same Genetic Distance will most likely not have the same report. In other words, since each marker has a different mutation rate, identical Genetic Distances will not necessarily yield the same probabilities.

Since FTDNATiP uses the individual Marker mutation rates, a 37 Marker test is equivalent to a 56 Marker test that uses the assumption that all Markers mutate at a standard rate of .0004 or a 110 Marker test with the standard Marker mutation rate of .0002.

 Once the selection appears on the match page, you will be able to select a match for comparison, and get a FTDNATiP report which shows the result of the calculation comparing two individuals. This report will provide the probabilities for each 100 year period for the common ancestor. The probabilities can influence or determine if you pursue a match. FTDNATiP can also be used to make the decision of whether you should pursue a paper trail connection between the ancestors of the two people who are a close match. FTDNATiP incorporates new mutation rates from the FTDNA/University of Arizona mutation rate study.

For both Group Administrators and individuals, FTDNATiP can provide useful information to assist you in your genealogy research. Below are some example outputs from FTDNATiP. Keep in mind that each report comparing two individuals utilizes in the calculation the individuals results and the specific Marker mutation rates. Therefore, two people with a Genetic Distance of 1 will most likely not have the same report as two other people who have a Genetic Distance of 1. In other words, since each marker has a different mutation rate, identical Genetic Distances will not necessarily yield the same probabilities.

Below are some examples from FTDNATiP. First is an example where two individuals are a 36/37 match:
 

-------------------Years--------------------
100      200      300     400     500     600       
56.46%  87.40%  96.84%   99.26%  99.83%  99.96%   Probability of common ancestor
In this example, there is a 56.46% probability that the common ancestor occurred with in 100 years, and an 87.40% probability that the common ancestor is within 200 years.

As you can see, this output format is much easier to understand than a graph!

FTDNATiP also allows you to enter the number of generations known where the two people do not have a common ancestor.

The above comparison between the two individuals did not include the any known genealogy information. The genealogy doesn't go back very far for these two individuals, due to a brick wall. It is known that the common ancestor did "not" occur in the last 4 generations, so a genealogically enhaced correction was then entered, and the calculation rerun, producing the following results:
  
100-200    300     400     500     600   700    
69.29%   92.09%  98.13%  99.58%  99.91%  99.98%
You can see how the probabilities changed with the additional information.

The custom calculation comparing two individuals provides probabilities that the common ancestor occurred for each 100 year period. This information can help you decide if you should pursue a paper connection.

In the above example, the common ancestor has a very high probability of occurring in the 1700's or 1800's. Depending on the surviving records for the geographic area, it would definitely be worth while to pursue finding the paper connection.

Consider the following situation: Two participants are a 34/37 match, and their ancestors lived in the same county in the 1800's. Should they be searching for a paper connection in the 1800's, or is it more likely that the common ancestor occurred much earlier?

The results from FTDNATiP are the following:
  
100     200      300     400     500     600       
3.68%  25.94%  56.38%  78.99%  91.23%  96.70%
In this case, it is highly unlikely that the common ancestor occurred in the 1800's. The probabilities show that the common ancestor was in the more distant past. Therefore, it would not be a wise investment of time to pursue the paper connection in the 1800's.

FTDNATiP does a calculation comparing the results of two persons, using the individual Marker mutation rates. A genealogy factor can be input into the calculations, by entering the number of generations known that the common ancestor did not occur.

Below is an example comparing two individuals who are a 34/37 match, and do not have a common ancestor in 16 generations:
  
400-500  600     700     800     900    1000
60.63%  86.22%  95.58%  98.67%  99.62%  99.90%
The paper connection may never be found for these two individuals, since Parish Registers only started in the 1500's in England. The time prior to Parish Registers is where the highest probability of a common ancestor occurs. Wills and Manorial Records would be the best source to find a common ancestor.