In this month’s Eneclann expert post Fiona looks at genetic genealogy.
DNA: Here’s Y.
My first introduction to genetic-genealogy was in 2009, when Eneclann was recruited to work on a new television series presented by Professor Henry Louis Gates - Faces of America. The relationship was a happy one, and we subsequently provided research for Finding Your Roots.
The premise of both programmes is to trace the participants’ deep family history and anthropology.
The genealogists start their research using historical documents to trace a family back as early as the surviving records allow. Once we (the genealogists) exhausted the paper trail, geneticists analyse the participants’ genetic code to trace their bloodlines, and in some instances identify an ancestral homeland, or confirm or deny a connection between individuals or families.
Genetic genealogy works because our personal history is written into our cells, which we inherit from our parents. Y-chromosome DNA is passed from father to son, and allows you to trace your paternal line. Mitochondrial DNA is passed from mother to child, and allows you to trace the maternal line. Science has advanced to such a stage, that we can now decode the genetic information recorded in all of us.
Genetic-genealogy is currently being promoted as the ‘future of genealogy,’ but it has also drawn down its fair share of criticism by genealogists on both sides of the Atlantic. In May 2012 John Grenham in his Irish Times blog criticised geneticists for using control groups that were too small to produce significant findings. Even more bluntly, in this week’s edition of Eastman’s online genealogy newsletter, Dick Eastman published an article on epigenetics, with a disclaimer to the effect that he doesn’t believe it, and that in his opinion it contradicts all the scientific evidence published to date. Quite simply epigenetics argues that a simple environmental effect such as nutrition or stress, can switch genes on or off, and this change can be inherited.
Epigenetics does not refute science - it marks the integration of several fields of scientific research, and is a huge advance in the causes of diseases. If we are ever going to find a cure for cancer or HIV, it will come through this research.
Genetic genealogy doesn’t just offer us the prospect of major advances in science or healthcare, it also offers us a scientific basis to challenge racism, because in the words of Henry Louis Gates, “DNA testing deconstructs the idea of race.” There is more genetic divergence between spider populations, or bird populations, than there is among all human populations.
Grenham’s criticism of genetic genealogy is closer to the mark. Genetics is a comparative tool. It allows you to compare markers found on your DNA for degrees of similarity with another person. The greater the number of markers examined (the ‘resolution’), the better the results. The more people you have to compare against each other, the more interesting the results.
So Grenham is quite right to question the findings of the TCD research group concerning descent from ‘Niall of the Nine hostages’ which was based on comparing the genetic markers amongst a control group of only 59 men. However, the TCD group has undertaken some excellent research, including a genetic study of the Butlers of Maiden Hall - using a control group of over 300 persons descended from a common ancestor who lived 400 years earlier.
Genetic genealogy has now reached a really interesting point. It’s affordable and offered by reputable companies like Family Tree DNA and 23andme.
Enough people have signed up to have their DNA tested and there are now a number of group projects in place to research the history of specific surnames, lineages and ethnic groups.
Ultimately my take on genetic genealogy is that although it lacks the precision of genealogical research, it can allow you to push back your family history story another 1000 years. What’s not to like?