African American DNA Research Forum
Re: DNA Testing Limits
In Response To: Re: Admixture vs Ancestry ()
There seems to be limits to a number of tests currently available. DNA Print's autosomal DNA test gives you a percentage of 4 broad groups based on about 175 SNPs (if I recall correctly from a few years ago), but they are proprietary, so you can't look at the data yourself and doing any further comparisons.
The CODIS markers (13 pairs of STRs) are so unique that they are used forensically, but in principle you can get a rough affiliation with ancestral groups. Be cautious about how to interpret this if there has been admixture. Also, percentage wise, you're only getting information from a few generations. You have 13 alleles from each parent, therefore, if things are passed on based on averages (supposedly Mendelian inheritance applies), then you'll get about 6.5/grandparent, 3.25/great-grandparent, 1.6/gg-grandparent, but unless you have those folks available & test them, you don't know which alleles came from which ancestor.
At this point the mtDNA testing, even with HVR1 & 2 matches, doesn't seem to lend itself to concrete matches in genealogical timeframes. Even with African Ancestry, I'm not sure if Howard & I really resolved why we ended up with different results even though we matched, as he never received revised results.
Also note that whether we're looking for matches in the literature or at how African Ancestry tests, many do not compare the full range from 16001 to 16569. Does this make a difference? I don't know, but I would like to know if there could be more specificity. Most of the articles that I've found online stop somewhere in the 16300s. My African Ancestry test results stopped there too. So, does this mean that any mutations in the 16400s and 16500s are meaningless (that they're all like 16519c?) or simply that that range wasn't tested?
I'm not a naysayer, just a questioner. I would have never imagined that we'd have this much DNA info available 20 years ago. Who knows what the next 20 years will bring?! But, I also believe that as consumers we should also be able to keep the companies on their toes. As a DNA Tribes user (with 5 generations of data) I would suggest being cautious about the value of the results if you have significant admixture in your family, or at least be willing to use the Omnipop Program to analyze individual alleles. (So, with FTDNA offering a test & saying use Omnipop, this might be the more cost efficient way to go, instead of DNA Tribes.)
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