The Y-chromosome is passed from father to son unchanged, except for a mutation about every 500 generations. Testing the Y-chromosome will provide you with a genetic finger print consisting of 12, 25, 37 or 59 numbers. By comparing this finger print to other Yehle's we can determine if we are related.

Testing with the 37-marker test. The 37-marker test is the highest resolution test available; we are not dealing strictly with quantity, rather than quality. While the 59-marker test has recently become available, it is too early to know it's value.