An introduction to Genetic Genealogy
Most sources used for genealogical research are written resources. Census returns, registration certificates and parish records are commonly used. Other sources such as tax assessments, muster rolls and judicial records etc are used by the serious family historian. They have in common the fact that they are all written and have had to survive centuries of perils: fire, damp, neglectful destruction. Indeed the person you may be hunting may have not been recorded in the first place! To a lesser extent oral sources from elderly relations may be consulted but with caution.
We are now entering a new era, with a new resource to use, the genetic information held in our genes. The once obscure scientific term D.N.A. is now used in common parlance. It has gained a mystical reputation through its seemingly miraculous powers.
The family history press mentions DNA from time to time, but the conclusion appears to be that there are only very limited results that can be achieved. But new avenues of research are opening up all the time. To put where we are into context, the human genome mapping project will not be complete until the early years of the next century. This is equivalent to say the early explorers such as Captain Cook discovering and starting to map such coastlines as Australia. Things which leading geneticists could not find just a few years ago are now being discovered. Importantly, as far as genealogists are concerned, this includes areas, which are potentially of great help to us.
A good example of the progress being made, is the finding of useful markers within the male chromosome called the Y-chromosome. In Sir Walter Bodmer's, "The Book of Man" published only a few years ago in 1994, it stated that in terms of the male chromosome, one male was indistinguishable from another. However work is now ongoing at several universities around the world, which is using such newly discovered markers on the Y-chromosome. This is usually with the aim of trying to answer such broad questions as, when did the ancestors of modern Man first come out of Africa or what were the migration patterns of various peoples across the world thousands of years ago. Nearer to our epoch, the Cohen study reported in the leading scientific journal "Nature" in July 1998 was a step towards a timescale more familiar to family historians.
If males can be distinguished, from millennium and eons ago, does this help the genealogist who deals in decades and centuries, and how and what can this achieve? Since May of last year a project has been progressing initiated by myself and researchers at a world ranking university to see if genetic theory can be transformed into useful genealogical practice.
The research has involved, so far, the analysis of the DNA of 66 males who are believed by traditional genealogical research methods to be either closely related or distantly related (up to 7th cousin) and share a common male ancestor. Also others are included which may be related, but whose ancestorial records do not exist far enough back, to prove the point.
As it is a happy co-incidence that surnames normally follow male genealogical descent, this should mirror an identifiable male chromosome being passed on generation to generation from father to son. There are of course a few exceptions to this rule; e.g. a person's mother is a biological fact, their father an assumption. Consequently it is hoped to help demonstrate for the benefit of the family historian, for example, that the g-g-g-g-g-g-g-grand father with your family name, which you may have spent decades tracing, is indeed the right one. Or that the family 300 years ago with the same surname but 30 miles away from where your researches have taken you, are the same family. Perhaps you have wondered which other subscribers in the national phone directory with your surname are very distant cousins.
Contrary to what a few people have assumed I have not been going around churchyards exhuming bodies to further the project. The evidence from centuries past is carried around by all of us in our genes today and cannot be lost like written records. Collecting samples for analysis is extremely simple and painless. The extraction and analysis of the DNA needs specialist equipment, but I can see such items becoming common place in a decade. It may compare with the development of computer technology from the early 1970's to the PC's of today.
As well as the male specific Y-chromosome being of potential help to the genealogist there is another piece of DNA, known as the mitochondrial DNA, which is only passed on to the next generation by women. But as the tracing of a direct female line only, is not traditional pursuit and the science is still beyond the reach of the ordinary family historian, little has been achieved here.
Some of you may be speculating whether DNA can be somehow used to trace all ancestors or descendants, male and female of a particular family. At the moment there does not seem to be an obvious suitable universal marker primarily because of the constant exchange of genetic material each generation. However we are still in the age of discovery with genetics, who knows what we may find in a few years time.
In the year, say 2010; genealogists may be starting to describe an ancestor or descendant in terms of a numeric code describing certain DNA markers.