20 February 2012

Dr McDonald's DNA Analysis, Pt 2

     I recently wrote about having my 23andMe raw data analyzed by Dr McDonald. Part of the reason I did this was to see if he could confirm the small segments of African and Asian that showed up in my DNA. He confirmed that they were "small but strong and likely real."  But here's the thing: both my Mom (at 23andMe) and Dad (at ftDNA) show up as 100% European. Where were these segments coming from? I thought that the best way to figure this out was to send him my parent's data as well and to find which one had those same segments in their data.

     My mom's data is from 23andMe. As I said, there she showed up as 100% European, with no other segments. Dr McDonald's results agreed. The only non-European data shows up in her X Chromosome, which he thought was "iffy." Here's her chart:

      Ok, so Dr McDonald has confirmed the interpretation of 23andMe's findings for my mom and myself.

     Next up: my dad's data. I tested my father at Family Tree DNA, where he shows up as 100% European.  But both my parent's can't have 100% European DNA if I have "strong and likely real" segments of African and Asian DNA.  It turns out that my dad does have those segments. I don't know why Dr McDonald found these segments and ftDNA didn't, but they are there. In the same locations as mine, plus some. He has .8% African DNA and .4% Native American (compared to my .6% and .3%). Here's his chart:

     So this analysis confirms the rumors of Native American heritage in my Dad's side of the family.  But there was no expectation of African DNA. Apparently though, this isn't uncommon. A lot of people with Colonial American heritage apparently have African segments in their DNA (read about them here on 23andMe's message board or this blog post).

     I wonder if this comes from the same family line or different ones? I wonder if I'll be able to find it? I highly suspect my Barfield family could be the source and I hold little hope of ever tracing that line any further back than where it's stuck in 1852.  Perhaps by testing more of my paternal relatives, I can narrow down the source.


JohnLloydScharf said...

What qualifications does this "Dr McDonald" have?

Valerie Craft said...

Dr McDonald is listed in the factory directory at the University of Illinois as a Professor Emeritus of Chemistry. Along with your results you receive a more technical explanation on how he came up with the results.

Annie said...

Hi Valerie,

I came across your blog while looking up Dr. McDonald. I've seen him mentioned a couple of times on 23 and Me (we've tested my daughter, adopted from China, and are new to the site). Does he require payment or do people just contact him and ask him if he will analyze the raw data? I haven't seen mention of fees from anyone yet so I was just curious. Thanks!

Valerie Craft said...

Annie, Dr McDonald will analyze your data free of charge.


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