Monday, 9 July 2012

Update on the DNA study.. and the FamilyTreeDNA summer price reduction

 It's been a while since I updated you on the progress of the DNA study, so here goes....


You may find it helpful to have the chart with all the results open in another tab, and here's the link:
http://www.familytreedna.com/public/Fitz-Henry/default.aspx?section=yresults


The study has been going for 4 years now, and we have had 14 men join it. Last year (2011) was our best year with 5 project joins, and we have had 2 joins in 2012 so far.


Here's the science...
The process tests the Y chromosome, which only men have, and the Y chromosome passes from father to son with the father's surname. The Y chromosome doesn't change ("mutate") very often which makes it ideal for studying its inheritance over a very long time  - many centuries.


The tests look at specific parts of the chromosome (markers) which have a tendency to show a repeat pattern. The number of pattern repeats are counted which gives the numbers that you see in the results chart. So when someone has a number 13 in the first column (all our men do) then it means that they have 13 repeats of the DNA pattern at a certain point. In our study we ask for 37 places on the Y chromosome to be tested. The more individual places which match up on different men's Y chromosomes, the more likely they are to be related. However we also know that over the centuries, the DNA changes slightly so this is when we see differences when we know people are related. More on that below.

The tests carried out on the Y chromosome are done in 3 batches or "panels".
The first 12 markers tested mutate very slowly indeed, so it gives a general feel that two men's distant common ancestor had been many centuries before. A perfect match of 12 can be encouraging but we have had 2 occasions where we have had a perfect match in the first 12, and then many mismatches in the rest of the markers, which show no calculated link for the last 24 generations, or the era when surnames were used in a familial way.
The next batch of markers 13-25 mutate more readily than the first 12, so this starts to show whether there really is a link between the two men tested.
The third batch 26-37 markers mutate more readily still and this can be useful to show who is a member of a particular family line of the same surname in near history (the last few hundred years!).


The most tested family we have is that of Enoch Fitzhenry (1752-1835). His descendants have been remarkably well documented due to a combination of well kept records in their family bibles and enthusiastic family historians in their family (a nod to Mrs Josephine Hodges here who did a lot of sterling work in the pre-computer age and who has been a friend to the Fitzhenry study since its start).
We have 3 men tested from Enoch's line which you can see together in the chart. Each one represents a line from a different one of Enoch's sons. Over the past 250 years mutations have crept in, even in the slowly changing first 12 markers. 
The sample from individual known as 230345 has a 12 in the fourth column where the other two descendants have an 11. However, overall the results do not differ by more than 2 markers out of the 37 marker total, and so this means that indeed we can say that all these men are true descendants of Enoch.
There is also a fourth test in this group, which comes from the family of John Fitzhenry (born 1800) of Oulartwick, County Wexford. This family is now in Australia, but has a very good paper trail back to this one townland. The DNA tests match 36 out of 37 markers with Enoch descendant 130259. 
We know that there has been no common ancestor between these 2 lines since before 1752, so to only have one marker difference over this timespan indicates a very close link between the two families, with perhaps a common ancestor only the generation or two before Enoch. We can also say with a fair degree of certainty that Enoch's family came from this east part of the county near Enniscorthy.

So far we have had no other close matches between any of the other men tested who are all from trees that so far we have been unable to connect in any other way. This indicates that there was more than one man who originally took the surname Fitzhenry and passed it on to his descendants. Or it may indicate somewhere in the tree what we genetic genealogists delicately call a "non-paternity event" (NPE). 
An NPE may happen covertly when a child is born of an affair out of wedlock, but it is not acknowledged either to the husband or outside of the family if he knows.
Or it may be very apparent that the child is not the son of the man from who he takes his name. This happens with:
  • adoptees; 
  • when a widow has married again and the children from her first marriage take the name (but obviously not the DNA!) of the new husband; 
  • when the child is given the mother's surname;
  • when a man has changed his surname in adult life, either to inherit a fortune or escape the long arm of the law.

  • If you are a Fitzhenry, Fitzsenry or even Fitzharris (a variant of the Fitzhenry name in Wexford) man and you are interested in finding out about your deeper family connections, please consider taking the DNA test. 
    Now is a good time to do it, as FamilyTreeDNA who host our study are having another summer sale, so the 37 marker test is now US$129 ($20 off) until 15th July. And if you have any questions or comments, please add them below or drop me an email at the usual address.

    Why not subscribe to this blog and get the updates sent to your inbox? Or send us an email about your Fitz(-)henry family links.

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