Hi,
I'm rather disturbed by this sensationalisum about a murder. DNA from a genetic genealogy surname group being used with out the volunteer admin giving permission and then the Media stretching the truth of what that DNA found and how it might be used. The person who gave the interview did not inform the surname admin what she was using it for .. she said she was helping a friend trace back to the Mayflower group. But not even that, the person she compared to does not connect to the Mayflower group. Just has the same last name.
A friend on one of the DNA mailing lists where we are discussing this horrible infringement on a person's privacy has written this to help explain. I hope you take the time to read it.
This rather "sensational" story may generate a lot of discussion among people involved in DNA testing for genealogical purposes:
My take is that this is a fascinating, but Good News/Bad News kind of story.... The good news is that DNA may eventually help solve a 20-year old murder case. The bad news is that it is reported in a sensational way that is somewhat misleading and incomplete. By it's very nature, the Y-DNA testing used in genealogical studies only results in identifying a "class" of male individuals that descend from a common male ancestor and cannot be used to exclusively identify an individual person. In some cases, there could be literally thousands of living males that would be members of this same specific "class" of individuals.
If ever theoretically couched as "evidence," it would therefore be properly categorized as "class" evidence rather than "individual" evidence. It would simply give you a "class" of individuals to look at, nothing more, nothing less. Also, since a proper "chain of custody" is not maintained in a Y-DNA sample submission for "genealogical-purposes-only" use, it would very properly be immediately suppressed during "evidence suppression hearings." The individual suspect then could only be positively identified through autosomal DNA tests that are properly collected, with "chain of custody" also being properly maintained on the samples. Theses autosomal DNA tests are actually a cluster of (13) designated autosomal chromosomes used in the CODIS (Combinded DNA Index System) standard observed by police laboratories and recognized by the courts. Humans have 22 pairs of autosomal chromosomes (CODIS looks at only 13 of these), and one pair of "sex" chromosomes (xx in females, xy in males). The CODIS panel specifically does not include the 23rd pair sex chromosomes because they are "non-coding," or that is to say they do not report individual traits beyond gender. In contrast, all autosomal chromosomes are "coding" and do include your individual traits.
Now back to the sensationalism flare of the story. If they had instead said that the suspect was known to have blood type "AB negative," people would quickly recognize this as a simple "class" of individuals who all have this same blood type living at the time in the greater Seattle metropolitan region. Bottom line, before anyone jumps to any conclusions about how this affects Y-DNA testing in genealogy studies, police use autosomal DNA tests (CODIS), and we ordinarily (with exceptions) only test the non-coding 23rd pair "sex" chromosome, which is called "Y-DNA" in males and "mtDNA" (mitochondrial DNA) in females. I truly hope they catch the suspect, but all Y-DNA did was narrow the field to a very large class of living male individuals.
Sorry to be long-winded, but I thought this story might generate some discussion. I know some of our more science minded members might "tweak" some of my terminology, but hopefully, I generally got it right.
name removed for privacy
Nelda
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