Announcement

Collapse
No announcement yet.

Y-DNR 67 & atDNA tests compared

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Y-DNR 67 & atDNA tests compared

    I have determined via Y-DNA & atDNA my "likely" paternal line shows a NP event with my grandfather. I have tested 2 males of this "new" paternal line at the 67 marker level. One has a 5 genetic distance computed to shared ancestor likely 50.41% at 10 generations and the other a genetic distance of 7 to 55.49% at 13 generations. The atDNA involves about 10 individuals and shows a high coincidence level, with a second cousin and a 1st cousin, 1x removed and a 3rd cousin relationship, etc. I guess I'm a bit confused with the mutation level on the Y-DNA. I thought it would be closer. Do/can that many mutations occur that soon? I was always under the impression Y-DNA was more "unchanged" Any input welcome.

  • #2
    Originally posted by dbethards View Post
    I guess I'm a bit confused with the mutation level on the Y-DNA. I thought it would be closer. Do/can that many mutations occur that soon? I was always under the impression Y-DNA was more "unchanged" Any input welcome.
    Here's my simplified understanding of STR mutation. (Someone please jump in if I mess this up.) The Y-DNA STR markers that are used to calculate genetic distance have an average mutation rate of about 0.0024 per "transmission event" (ie new generation). If you test 67 markers, the aggregate mutation rate per transmission event is 67 * 0.0024 = 0.16. In comparing the genetic distance between two lines of males, you have 1 transmission event per generation for each line. So for 2 males lines, you would expect to see a divergence of about 2 * 0.16 = 0.32 mutations per generation in a 67-STR test. So after 10 generations, you would expect about 10 * 0.32 = 3.2 mutations.

    Comment

    Working...
    X