I absolutely agree with Ralph Sayre and you.Here is what I think. I am concerned that we are placing a whole lot of faith in cheek swabs for Genographic Y DNA testing.Based on the type of test being done, the results cannot possibly have 100% accuracy.It is important to know both the negative predictive value as well as the positive predictive value of these cheek swab tests.This tells us how often a test that is negative is true and how often a test that is positive is true. Also, the rate of false positives an the rate of false negatives. Are the tests all being done using the same instruments with the same calibrations in every case? These are just some of the questions I have. Blood tests would be more accurate, but even blood has its’ limitations. Much of the general public believes that a DNA blood test can prove paternity, for instance.But that couldn’t be more untrue!The DNA test can prove that a person could not be the father.And if the test is positive for paternity it is merely a probability that a person is the father.So many times with DNA testing we are looking for a good strong negative.A positive result is not ever 100% accurate. A positive result gives ahigh probability of paternity (enough for the courts), but not 100%.If the result is negative, you can say with 100% accuracy that the person is NOT the father in paternity testing.
So, is the genographic testing of Y chromosomal DNA any different from the paternity testing we do every day in the United States?If you send in a cheek swab and the result is that you are DNA Haploid group R1bC for instance, does that mean that with 100% accuracy that you are NOT anything else?Or is this a degree of probability that you are R1bC?If it’s probability, define that.
These concerns are just off of the top of my head as a trained biologist.I’m not involved in any way with this DNA research.I’m sure that more learned scientists than I can pick the whole process apart much better.
If you are a man, you have the Y chromosome and are a prime candidate for this genetic research.But take your results with a skeptical eye until science is better at this type of testing.