Re: DNA Testing
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In reply to:
DNA Testing
Bob Barrow 5/24/08
The 7% black is within the margin of error, so you can ignore it. People need about 20+% actual admixture for the results to be reliable. People inherit 50% of each parent's DNA, but the amount from each grandparent is variable.
It is very unlikely that you would show a 20+% admixture if she were only 1/4 Native American. You might if she were 1/2, even though the expected value would be 12.5%.
By testing relatives you can also test different lines with Y-STR and mtDNA tests. They can detect NA ancestry back thousands of years, but they follow same-gender lines.For Y-STR test, the subject has to be male. For the mtDNA test, the subject can be male, but it tests the all-female line of his mother.
There have been a number of posts on this subject, so I would recommend searching with Native American, Indian, mtDNA, etc. for more details.