Friday, July 19, 2019

Analysis of possible recombination of my Choctaw Autosomal DNA



My daughter received 27.9% of my father's DNA and 22.1% of my mother's. That got me thinking of the potential changes in inheritance you may see in recombination when you have one specific heritage you want to track. Given in the table below is genetic inheritance using the computation of a range instead of set DNA inheritance from a grandparent where the grandparents had either Choctaw or Anglosaxon (meaning European/American) heritage. You could substitute any heritage in here if it weren't at this point mixed, such as those who are British or American, because they often show a great mixture. It would work for Chinese, Italian or Swahili but not British or American. It represents the possible maximum range of inheritance of that DNA, but of course, as you get more distant from the full blood ancesor, it is possible that less DNA, or none of that DNA will get passed on.

I personally have tested with two companies. My daughter and my grandfather's female first cousin tested with Ancestry. My parents and my first cousin have tested with 23andme. Since each test has it's own range of total cM, ranging from 6950 cM for Ancestry to 7566 cM for gedmatch purposes, I have chosen my total cM's based on the result of my test to my daughter where 7162 cM is her total DNA with each X chromosome being 194.7 cM.

Now the recombination of X in inheritance is it's own animal. There are bloggers and researchers who have documented one entire strand (one parent) passing down from female to female for several generations. My daughter got a mix of my parents with more of my father's X chromosome than my mother's. Since a large portion of my mother's identified Native DNA is on her X chromosome, it is worth mentioning that my daughter received none of it.

Below is a table that starts with my earliest true half- Choctaw ancestors, children of a white man and a Choctaw female and then their descendants. I wanted to see what the ranges could be, when you took away the old standard, child of a half Choctaw is one quarter, and then their child is one eighth and so on. The results are interesting.


Person
Paternal
Gfather
Paternal
Gmother
Maternal
Grfather
Maternal
Gmother
Possible inheritance range in cM (%)
Peggy
Anglo
Anglo
7162
7162
3581 cM
(50%)
William Hall
Anglo
Anglo
7162
7162
3581 cM
(50 %)
Susan Riddle
Anglo
Anglo
7162
7162
3581 cM
(50%)
John Gardner
Anglo
Anglo
7162
7162
3581 cM
(50%)
Alatima
7162
7162
7162
7162
7162 cM
(100%)
James Trahern
Anglo
Anglo
7162
7162
1790.5 cM
 (25%)
Sarah Hall
Anglo
7162
Anglo
7162
3151.2-
3976.4 cM
(44-56%)
Samuel Gardner
Anglo
7162
7162
7162
5156.6 -
5569.2 cM
(72-78%)
Mary *assumed FB*
7162
7162
7162
7162
7162cM
(100%)
Robert Trahern
Anglo
3581 cM
3581 cM
3581 cM
 2363.5-
2997.3 cM (33-42%)
Cornelia Gardner
3581 cM
7162 cM
7162
7162
5884.4-
6568.3  cM
(82-92%)
Margaret Trahern
1790.5 cm
3151.2-3976.4 cM
5156.6-5569.2 cM
7162 cM
4012.1-
4953.1 cM
(56-69%)
Son/dtr of Margaret
Anglo
Anglo
2363.5-2997.3 cM
5884.4-6586.3 cM
1814.6-
2673.9 cM (25-37%)
Gfather
Anglo
Anglo
Anglo
4012.1-4953.1 cM
882.7-
1381.9 cM
(12-19%)
Gfather's Cousin
Anglo
Anglo
Anglo
4012.1-4953.1 cM
882.7-
1381.9 cM
(12-19%)
Mom
Anglo
1814.6-2673.9 cM
Anglo
Anglo
399.2-
746 cM (5.5%-10.4%)
Me
Anglo
Anglo
882.7-1381.9 cM
Anglo
194.2-
385.6 cM
(2.7-5.4%)

My cousin
882.7-1381.9 cM
Anglo
Anglo
Anglo
194.2-
385.6 cM
(2.7-5.4%)
Daughter
Anglo
Anglo
Anglo
399.2-746 cM
87.8-
208 cM (1.2-2.9%)



Notice that my grandfather should be between 12-19%, my mother should be 5.5-10.4%  and I should be 2.7-5.4%,

So how does the different genetic composition comparisons compare with the expected range. I made a table below. For clarification purposes, on the Gedmatch Admixture- MDLP World 22 I used the following results mesoamerican, artic american indian, North American indian, South American indian, Paleo Siberian, and because of some research I read, melanesian and austroeasan. I am not sure the cM for my heritage so I did not include that in the table.


Person
Expected Range
Ancestry DNA %  (cM out of 6950 cM)
23andme
%  (cM out of 7438  cM)
FTDNA
% (cM out of 7160 cM)
My heritage
Gedmatch
MDLP world22
% (cM out of 7566 cM)
My grandpa’s
cousin
12-19% (882.7-
1381.9 cM)
13%  
(903.5 cM)
NA
14%
(1002.4 cM)
NA
16.7%
(1263.5 cM)
My Mom
 5.5%-10.4% (399.2-
746 cM)
NA
9.3%
(691.7 cM)
7 %
(501.2 cM)
12.3%
9.75%
(737.7 cM)
Me
2.7-5.4%
(194.2-
385.6 cM)
3%
(208.5 cM)
4.6%
(342.1 cM)
2%
(143.2 cM)
3.2%
4.5%
(340.5 cM)
My cousin
2.7-5.4%
(194.2-
385.6 cM)
NA
3.5%
(260.3 cM)
3%
(214.8 cM)
NA
4.11%
(311 cM)
My Daughter
1.2-2.9% (87.8-
208 cM)
1%
(69.5 cM)
NA
<1 p="">Less than 1%
1.4%
2.16%
(163.4 cM)
 


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