Ok, maybe Webster doesn’t agree with me. On the other hand, Daniel Webster in 1806 didn’t know what DNA was either. Today the common tests used in genealogy are available by mail order. These tests don’t unravel your whole DNA, just the segments pointing to ethnicity or parentage. Don’t strain your brain trying to understand the chemistry. You don’t need to know how a laser pointer works to be able to use it as a cat toy.
There are three types of commercial DNA tests available; they have different uses. Y-DNA tests only reveal the direct male ancestors. John Dodge III, John Dodge II, and John Dodge Sr. all share a gene that gets passed on to the next males. The mtDNA test tracks women only. This test only reveals mother, grandma, great-grandma and so forth. The third test is autosomal. This test is recommended by Ancestry.com (not a plug for their product.) The test is done by a third-party lab. Customers choose which databases to share results with. Here is my consumer warning tag: That DNA profile can be used by law enforcement. Ancestry.com claims to have 20 million samples matched to members. The more samples collected across the world the better. The autosomal test includes all your ancestors, male and female. However, the results are very generalized. Results are expressed in percentages. If your grandma Johanna was born in Sweden and all her ancestors were born to Swedes, your test would probably show up as 25% Swedish. You have four grandparents, so one quarter of your DNA came from each grandparent. This only works because hundreds of years ago people didn’t travel much and intermarried with families in the same geographical region. The same genes got more concentrated and specific to a group who stayed for generations isolated from others. So, researchers seek out samples from across the world. Using the existing database, the test can predict that you had ancestors from Ireland, sometimes pinpointing a gene shared by a small group still living in the Cork Headlands. For most people, it just indicates a percentage of ancestors from Scandinavia and a percentage from Africa. All interesting stuff but it doesn’t nail down specific ancestors. The results can be used to find living relatives. Adopted sisters have reconnected this way. You have enough shared genes to tell if another person is probably your second cousin, if he submitted his results to the same database you are using, matches are suggested. It is up to you to compare trees and find the common ancestor.
Ed Peck can be reached through this newspaper or the RBC museum. Suggestions for future columns are welcome.
BY ED PECK
Special to the Herald Times
