Saturday, July 28, 2012

Genetic genealogy journey - FamilyTreeDNA Family Finder - Part 3


In Part 1 and Part 2 of my FamilyTreeDNA (FTDNA) Family Finder blog posts, I looked at the results for the Population Finder test for myself and my Dad. In this, Part 3, I will explore the other aspect of the Family Finder test, the matches.
I have decided to focus first on Dad's matches and my matches in common with Dad. Including myself, Dad has a total of 140 matches. Including Dad, I have a total of 126 matches. Dad and I share 59 matches in common. Borrowing an idea from Shelley at the Twigs of Yore blog, I have decided to illustrate the current Family Finder matches for Dad and myself with a basic Venn diagram.
FTDNA Family Finder Matches as of 28 July 2012:
Dad and I have 59 matches in common.
I have 66 additional matches from Mum's side of the family.
Dad has 80 additional matches who do not match with me.
(For the purposes of this illustration I have left out our matches to each other, e.g.
if I include Dad my total number of matches is 126 and if I include me Dad has a total of 140 matches)
I recently subscribed to the RootsWeb Autosomal DNA mailing list and have picked up some great ideas for sorting and analysing data related to Family Finder matches. Using some of these ideas, I have downloaded the Chromosome Browser results data files (in .csv format) for Dad's matches. You can only download the data for five matches at a time, so this is little time consuming. After I downloaded the data for all matches, I combined them into one spreadsheet (in my case using Microsoft Excel) which I can sort by match name, chromosome number, matching segment start location and end location, centimorgans (cM), matching Single Nucleotide Polymorphisms (SNPs), and I can add other columns such as a column indicating whether that match also matches me on that same segment.
Using this spreadsheet and the Chromosome Browser on FTDNA's web site, I can already see that several of Dad's matches share segments in common. From email correspondence I have found that some of those matches also share segments in common with each other, indicating that they probably share a common ancestor. I have used different coloured highlights within the spreadsheet to show where several matches appear to overlap on the same segments. As new matches are found I can easily download their data from the Chromosome Browser, add it to this spreadsheet and quickly see where they match in common with Dad's existing matches. Additionally, I am also adding Dad's matches from Gedmatch to this same spreadsheet. Again, I am grateful to several of the subscribers of the Autosomal DNA mailing list for these analysis ideas.
In addition to the spreadsheet, I have also created a Notebook in Microsoft OneNote called 'Genetic Genealogy' with a folder named 'Dad's Matches' to store notes and correspondence relevant to each Family Finder match. I am utilising the tags in OneNote to help keep track of any common factors between the matches. For example, I have created tags for:

  • FTDNA's suggested relationship range '2nd', '3rd', '4th to remote cousin' etc. (It appears, from my Dad's and my results, that the relationship is usually more distant than suggested.)
  • Chromosome number on which each match shares the largest segment with Dad.
  • Surnames in common between my Dad's family tree and the match's family tree.
  • Localities in common between my Dad's family tree and the match's family tree.

So far I have contacted about 17 of Dad's matches and have received replies from many, but not all. Some common factors between matches are already becoming apparent. One match shares an ancestor with a Northern Irish surname in common with an ancestor of my Dad, other matches appear to share localities in common such as Counties Kildare, Westmeath and Galway in Ireland. Interestingly, several of Dad's matches have family trees linking back into early colonial America, suggesting that the ancestor in common with my Dad must have lived in the 1600s (or even earlier?) in England or Ireland. 

In Part 2 of these Family Finder posts I examined the unexpected Middle Eastern component of the Population Finder result for myself and my Dad. After a lot of reading over this past month, I realise this result is quite common among others who have a well documented genealogy trail in the British Isles. I recently read a post at Roberta Estes' blog DNAeXplained – Genetic Genealogy and was particularly interested in one part the comment that Debbie Kennett left on that post:
"It might perhaps be significant that the people I’m seeing who do have this Middle Eastern percentage often have a large chunk of ancestry from Devon."
That might explain the interesting results for my Dad and me, as we definitely have Devon ancestry. However, a couple of my Dad's more distant (5th to remote cousin range) matches in Family Finder, whom I have not yet contacted, appear (based on submitted GEDCOM files or surname/location lists) to have ancestry which doesn't relate in any way to my Dad's known ancestry (e.g. Jewish, Portuguese, Spanish, Sicilian, German, Swedish etc.) One of FTDNA's FAQs for the Family Finder test asks if such matches may be 'false positives', to which the answer is:
"No, these are not false positives. You share real Identical by Descent (IBD) segments with your match. You may share some autosomal DNA with cousins beyond genealogical times. Your relationship may be as close as 4th cousins. It may also be as remote as 20th cousins. It is not possible to say exactly where the relationship falls. Our Advisory team has labeled these cousins Speculative Relatives."
So I guess I can't discount any family stories of Spanish ancestors yet. It would be great if some of my Dad's close and more distant known cousins would be interested in joining in and taking a Family Finder test (hint, hint, hint) :) Finding which matches Dad's cousins share in common with Dad would help to narrow down which branch of the family tree the matches' common ancestor comes from. Please contact me if you are interested. It would be great to involve other cousins. Thanks. Taking this Family Finder test has, in my opinion, been a very fascinating and worthwhile genealogy journey.
Creative Commons License Australian Genealogy Journeys by Aillin O'Brien is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Australia License.Permissions beyond the scope of this license may be available at http://ausgenjourneys.blogspot.com.au/p/copyright-terms.html. .

5 comments:

  1. I'm hoping that once I do my DNA test it will start to make sense -I'll be back to refer to your posts in more detail.

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    1. Thanks Pauleen, I think once you have the tests you find the reading makes more sense, that's how I have found it when I look back over other peoples' DNA test blogs.

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    2. Some of the science is beyond me but I am trying to follow the advice some of the more knowledgeable folk on the mailing lists suggest, working OK so far I think.

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  2. That sounds like it might be okay then Aillin. I did science donkey's years ago but somehow the DNA stuff is making me befuddled. Seeing is understanding perhaps.

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    1. Yes I only did science to year 10 (chose humanities and IT subjects instead!) So I'll leave the scientific stuff to the experts. I'm thinking maybe I need a refresher in maths and statistics though! I'm finding it is all a bit like computer programming "if person A matches person B but does not match person C then..." etc.

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