Genetic Testing, what to do after 25 Markers

I was working with a project member this morning who had done 25 markers and was looking for how to make sense of the match.  Here's what I told him, information that will be helpful for everyone:

I see that you have only tested 25 markers. You have 16 exact matches at 12 markers. While you are related to all those matches, they could be relatives prior to the last 700 years, when surnames came into existence. Thus, 12 marker matches do not mean much, unless you already know for sure (through a paper trail) your relationship.

At 25 markers, you have one match at a genetic distance of 1. This, again, does not mean much. Your match, Michael X*, has tested at 67 markers. So, you probably ought to upgrade your testing to 67 markers to see if you are still just one marker off an exact match, or if the match falls apart.

Here are two additional strategies you can try. Through your documented family history, find another male Taylor from your line (as distant a cousin as you can prove is your relative) and have him test. At that point, he will either match you closely (65, 66 or 67 or 67 markers), or not. If you do not match, then the paper trail is not accurate, and one or both of you descend from a line of a different male progenitor than is indicated on your genealogy.

A second strategy is to do the Family Finder test. Here you are matching autosomal DNA, matching across all family lines. While I am excited about this DNA test, and have done it for two of my Taylor and one Robinson relative, the matching is difficult so far because the people I've matched have not responded with their genealogical information. I'm not blaming them, as the protocol for how to work with others in matching autosomal DNA is not developed and many of them may be clueless. So, the science of autosomal matching is definitive, but the cooperating with one another to discover how we are related is in its infancy.

I hope all this is helpful. Please do more y-DNA markers, at least 67. Then consider the Family Finder test.  Together with the Taylor team, we should be able to assist you with your genetic matches.

Lalia
*Complete name not give for reasons of privacy.
Note: the image is a Taylor important in the history of Louisville, Kentucky, whose name I did not get.

An Interesting Taylor by Marriage

Here is the description directly from the New York University Library website:

Treva Margaret Taylor, nee Hampton, (1929-2006) was an avid reader throughout her life, not only of Harlequin romances, but of other novels and of history. She instilled the love of reading not only in her own children, but also in scores of neighborhood children. She was always ready for a trip to the local public library. Taylor subscribed to the monthly Harlequin service and received a number of titles in each package during the 1970s and early 1980s. Once read, the novels were kept in numerical order by the publisher's number on bookshelves. Her collection is reminiscent of dime novel collections from the Nineteenth Century, presenting a cross-section of popular romance during the growth of the feminist movement.

http://dlib.nyu.edu/findingaids/html/fales/harlequin.html

Apparently this collection is massive!

Just one more of an interesting collection of Taylors...

67-Marker Matches

Hi Again,

I'm continuing with more material from Ralph Taylor on the meaning of matches. What does it mean if you match 67 out of 67, commonly written 67/67, with another person? There is about a 50% likelihood that you share the same great-grandfather! Thus, you are second cousins. You could be slightly closer related or slightly more distantly related, but you are related recently as genealogists measure relationship!

As Ralph Taylor says, "67-marker matches, if you’re lucky enough to find one, are very precise; you may need to account for the birth dates of the matching individuals. The main problem is that most people have done a lesser test, so you can only compare against the markers they had tested." Thus, refer to earlier blogs which discuss 37 marker matches and fewer matches.

Should you match in the range of 65-67/67: You share a common ancestor and he almost certainly lived within a genealogic time frame.

o A perfect 67/67: The 90% probability level is a TMRCA of <= 11 generations, >= 1735 AD; 70% is <= 6 gen., >= 1860 AD; & it’s 50% probable that your common ancestor is your great-great-grandfather.

o 66/67: 90% is <= 18 gen., >= 1560 AD; 70% is <= 18 gen., >= 1730 AD; 50% is <= 7 gen., 1835 AD.

o 65/67: 90% is <= 24 gen., >= 1410 AD; 70% is <= 16 gen., >= 1610; 50% is <= 12 gen., >= 1710 AD.

Should you match in the range of 62-64/67: You share a common ancestor, who may or may not have lived in a genealogic time frame.

o 64/67: 90% is <= 31 gen., >= 1235; 70% is <= 22 gen., >= 1460; 50% is <= 16 gen., 1610.

o 63/67: 90% is <= 37 gen., >= 1085 AD; 70% is <= 27 gen., >= 1330 AD; 50% is <= 21 gen., >= 1480 AD.

o 62/67: 90% is <= 43 gen., >= 930 AD; 70% is <= 32 gen., >= 1200 AD; 50% is <= 26 gen., >= 1360 AD.

We've have spent a number of blog entries discussing the statistical meaning of matches. You do not need to completely understand statistics or probability, though. What you do need to do is to investigate the family trees of anyone who closely matches you. For example, with a "perfect" match of 67/67, you and the other person should be able to find your common ancestor fairly easily. One hopes that each of you has some information about your mutual family tree so that you each gain significant new information. After all, that's why you chose to participate in this project.

The good news is that eventually sufficient y-DNA records and pedigrees will exist to satisfy every participant's desire for knowledge of their roots!

Best wishes as we move towards that goal.

Lalia

25-Marker Matches

What happens if/when we have 25-marker matches?

Well, the good news is that 25-marker matches allow finer interpretations:

· 24-25/25: You share a common ancestor, probably within a genealogic time frame. (The numbers of generations & dates below are approximate.)

¨ A perfect 25/25: The chances are 90% that your most recent common ancestor is within the past 28 generations, roughly since 1300 AD. It’s 70% that the time to the most recent common ancestor (TMRCA) is within 15 generations >= 1630 AD and 50% the TMRCA is <= 9 gen., >= 1780 AD. Thus, as we will find out when we look at greater numbers of markers, discovering a "perfect" 25/25 match only means that you share an ancestor who lived about 1300 (90% probability) to 1780 (50% probability).

A 24/25 match means even less. 24/25: The 90% probable TMRCA is <=48 gen, >= 800 AD; 70% is <= 30 gen., >= 1260 AD; 50% is <= 21 gen., >= 1480 AD.

Matching 23/25 may not illuminate your genealogical studies at all, as your common ancestor may have preceeded records with surnames. 23/25 or worse: You share a common ancestor, but he may not have lived within a genealogic time frame

Looking at this in terms of generations, instead of years, the match of 23/25: 90% TMRCA is <= 67 gen., >= 330 AD; 70% is <= 46 gen., >= 860; AD; 50% is <= 34 gen., >= 1160 AD.

While a 22/25 match means even less. 22/25: 90% TMRCA is <= 86 gen., >= 140 BC; 70% is <= 61 gen., >= 480 AD; 50% is <= 47 gen., >= 830 AD.

Input from Ralph Taylor and Lalia Wilson

Terminology Used in Genetic Genealogy

Hi,

Here are some terms that Ralph Taylor provides to help you understand your reading of articles and blog posts about genetic genealogy.

MRCA: The most recent common ancestor shared by two or more persons with a DNA match. We are concerned only with the most recent, because preceding ancestors will also be shared.

TMRCA: The probable time to the MRCA, expressed in generations.

Probability level: The cumulative probability, expressed as a percentage, that a MRCA lived within the specified number of generations. Here, we give three probability levels, 90%, 70%, & 50%. 90% means the chances are 9/10 the TMRCA is <= the given number; 50% probability is as likely to give a low TMRCA as a high one.

Genealogic time frame: A time for which it is feasible to specifically identify an ancestor, generally from about 1350 AD to the present.

Generations, length of: This is an estimated average of 25 years, developed from 18th and 19th century America statistics. We use the estimate to convert generations to common dates. Other societies may have had a different generational length -- either longer or shorter.

<=: Means less than or equal to, the maximum generations number for that probability level

>=: As applied to dates, means no earlier than the given date.

US President Zachary Taylor

Here are some comments following up on the subject of the previous post. These are from fellow Taylor DNA project administrator, Leigh Taylor:

Have you ever been told that you were related to Zachary Taylor? If so, you’re not the only one! But this is only is true for a very few people. He is probably the best-known and most prominent Taylor in US early history. He is also the base of many myths for our participants.

It might be helpful to view the tree for Zachary Taylor at Rootsweb's WorldConnect. [See link in previous post.] As it turns out, Zachary had no living direct male descendants. His only two male grandchildren died very young. You have to look further up/down his tree to his siblings & cousins to find your connection to Zachary, if any. Most of those branches also "daughtered out". The short version is: If your surname is Taylor, you're probably not related to Zachary.

If you or members of your family have been told that you are related to Zachary Taylor, you might want to compare your markers with the markers for participants in group 2 and study their family trees. Members of Group 2 that claim to have a paper trail to Zachary are:

Kit# 54705 - 12 markers but no tree submitted

Kit# 58928 - 67 markers but no tree submitted

Kit# 24691 - 37 markers = Kit# N2079 - 12 markers

Kit# 48113 - 37 markers similar to above

from Kit# 48113:
1. James Taylor (1610 ENG- 1698 VA) +m2 Mary Gregory
2. John Taylor (1696 VA- 1780 NC) + Catherine Pendleton
3. Joseph Taylor (xxx VA - xxx xx) + xxx

from Kit# 24691 and Kit# N2079:
1. James Taylor (1610 ENG- 1698 VA) +m2 Mary Gregory
2. John Taylor (1696 VA- 1780 NC) + Catherine Pendleton
3. Edmund Taylor (1723 VA- 1808 NC) + Ann Lewis

Welcome to the Taylor DNA Project Blog—Taylor Topics!

In the interests of serving project members and forwarding the educational and informational goals of the project; the project administers have decided to use a blog for communicating with members.

Our goal is to provide you with information that helps you understand your family tree and to connect with relatives and go further backward to previous generations in your family tree.

The blog will feature short pieces of information about DNA testing, Taylor genealogy, famous Taylors and associated topics.

If you have managed to have a breakthrough regarding your Taylor line through using this project, please send the story to Lalia Wilson (LaliaW@aol.com) so that we can share your story with other project members.

We look forward to hearing from you and answering your questions so that everyone’s questions are answered.