Why is YDNA limited to 10 generations of direct-line male descendants?

Question

Why is the YDNA limited to 10 generations of direct-line male descendants?  A genetic distance of 2 on a YDNA-37 test has a 95% probability that a common ancestor lived no longer than 14 generations ago.  YDNA is highly reliable well past the limits of autosomal DNA.  It would be helpful to be able to extend at least to the earliest Colonial ancestors from the Lords Proprietor Era.

For example, the Jordan Surname Project on FamilyTreeDNA breaks into family groups that are now about 14 generations from the patriarch of the JG grouping.  It is hard to use WikiTree to be able to identify common descendants when the suggestions fall off of the chart.

Comments

Thank you.  Last week when I looked at it, the YDNA match suggestions in my tree ended with Jordan-602, which is the 9th generation in my tree.  The information was missing generation 10 - 13.  

Perhaps it was because a bad merge was made, eliminating my ancestors in the merge.  I split the men back apart because the YDNA indicates that they were indeed two different men.  

A few days later, I check it again and the YDNA suggestion still wasn't there.  I looked it up in the YDNA help information and it said that it would carry direct male-line for 10 generations.  So, I thought this is what may be what caused the confusion encouraging someone to merge two Charles Jordan's with non-matching YDNA descendants.

I must have gotten caught in the 48 hour refresh loop because the YDNA suggestions are now back for Charles Jordan-191 and his ancestors.

Thank you for pointing it out that it is indeed unlimited Y-DNA direct male-line descendants.  This is quite helpful.  I just wish that more of the Jordan men who have taken the YDNA test on FamilyTreeDNA would link not just their Family Finder autosomal DNA results, but their YDNA results as well.

Answer 1

Hi, Kerry. WikiTree's propagation of yDNA test information--so that suggestions appear in the "DNA Connections" panel on the right-hand side of ancestors' profiles--isn't limited to any specific number of generations. Autosomal DNA is restricted to eight degrees of separation, or eight birth events, which means vertically back to 6g-grandparents and horizontally out to 3rd cousins. But there is no such restriction placed on yDNA or mtDNA; suggestions and test-taker information will flow back to the earliest profile in the contiguous, unbroken line.

More info here, and here's an example of Sir William Smyth de Caryngton, b. 1075 in Cheshire, England, with Rand Prouse's yDNA test info propagating to him up the tree. Shout back if I've misunderstood your question!

Answer 2

I am thinking that you don't have that many that match you on 67 markers or what ever you are looking at.. your DNA is probably more rare.. that is lucky in many ways.. you won't match a lot of people who are not family.. Look at 37 markers and see you show more out.. that will give you all of the 37 markers and the 67 markers to look at and match with. :) I am sure that will pop right out! Though 37 markers is harder to match up as they have 30 invisible markers they are not matching to... but yeah I think you are not matching. I am that way as well, or my brother is. I have only 17 matches at 67 total and it only goes out to 7...  Any further out I am probably not really matching as the 7's I am matching to are Vests and Steels, none are White's..  I am going for those known Whites as matches if a Vest or Steel matches in a 1 or 2 generation, I might start linking up with them and seeing if any of our trees go to the same areas..

Comments

Thanks Mary.  There are 40 YDNA-67 matches and 60 YDNA-37 matches on FamilyTreeDNA.  Unfortunately, many do not have trees on FamilyTreeDNA and even fewer have them posted in WikiTree.

I'd be curious if your White's overlap with Henry White-462.  I know very little about him other than he had a daughter Abigail White-461 who married Charles Jordan-191.

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lol I am new here, I emailed you back at NoReply haha Yeah, it is sad that a lot of people don't put their trees so we can see where we are connecting our DNA but it could be thousands of years back and but at least we can check. Worried some are getting old and their family have no interest. Keep emailing them once a year or q 6 month and tell them you are matched family! At least to those you know are close family! Sometimes they will reply. The Whites I have little knowledge of but photos I was sent of their decendant from Hugh White. See we were in Scotland all that time till 1921, and never followed their trees cause we never met up.. YET! lol Hugh White son of Rev Adam White Hugh's-son John b. 1706 Antrim Ireland - son Thomas - b. 5 MAR 1754 Chester Co. PA - son James b.5 DEC 1794 Ruthoford NC, - son Robert Osborn White b. 5 JUN 1824 Bond Co. IL, - son Robert Renshaw White b.10 APR 1878 Mulberry Grove Bond IL, - son John Kenneth White b.30 AUG 1909 - son Ronald Eugene White b. 21 FEB 1948.. and then living children. Can't give you more than that on that family as I have not looked it up.. this is a direct line. to Rev. Adam White and our direct YDNA decendant. Hugh was in the US  before1715 his family 1722 as well as all the children listed. We found another son of Rev. Adam White who stayed in Scotland named George Whyte/White. probably b. before Moses White because of the time frame. and other evidence we are coming up with.