FamilyTreeDNA Learning Center – Bob, John, and I have the same Genetic Distance. However, when compared, we have different probabilities for sharing a common ancestor, for example, within eight generations. Why?

Bob, John, and I have the same Genetic Distance. However, when compared, we have different probabilities for sharing a common ancestor, for example, within eight generations. Why?

FTDNATiP™ uses both the number of mismatches and the mutation rates of individual markers in calculations. This means that although two men may have the same number of mismatches, they may not have the same predicted Time to Most Recent Common Ancestor (TMRCA).