You find you have a genetic match with someone else - how do you use this information to research your family tree?

First, you have to realize your mtdna result tells you about only one of your many female ancestors. Your mtdna is passed from mother to child, but not from father to child. Therefore your mtdna lineage runs only along your maternal line - your mother; your mother's mother; your mother's mother's mother; and so on. This is only the lowest branch of your ancestral tree, as usually portrayed in the patriarchal standard:

The mtdna result tells you nothing about the other branches of your ancestral tree other than the one marked in pink.

That said, it should also be noted that in the male-dominated genealogy of the past, only the upper most branch of the ancestral tree was thought to be of interest (marked in blue). So studying the mtdna line represents the women's liberation counterpart of the traditional patrilineal research.

Furthermore, a case can be made that both the patrilineal and matrilineal descent lines make a unique and disproportionate contribution to what makes you - you. The patrilineal line represents the y-DNA, received only by men, making up 1.6% of a man's DNA, and passed without change from father to son. Furthermore the y-DNA is what makes a man different from a woman. A man's most remote ancestor on the patrilineal line will still have the same 1.6% of the genetic code common with that man. The other ancestors, by comparison, will have contributed a much smaller percentage past the fourth generation (e.g. each of 16 great-great-grandparents only contribute 6% of your genes; each of 32 great-great-great-grandparents only contribute 3% of your genes; each of your 64 great-great-great-great-grandparents only contribute 1.6% of your genes). But a man's paternal ancestor, no matter how remote, still has the same 1.6% of common genome. This inheritance may explain some persistent patrilineal family characteristics, such as the Hapsburg lip or certain emotional tendencies. A girl doesn't receive any of this y-DNA. Therefore any of these characteristics, or those of her paternal ancestors, are not passed on to her.

In the case of mtdna, this is outside the genetic inheritance and a very tiny percentage of your total unique DNA. The mtdna is found in the mitochondria, little energy factories that provide energy to every cell in the body. However these are such fundamental processes that they likely have a very basic effect on how we turn out. Some genetic diseases or genetic predispositions to disease have been identified in mtdna. So it is not out of line to believe that some essential aspects of our physical, and perhaps mental essence, are passed only from mother to daughter. (It is also passed from mother to son, but the son does not pass it on to his offspring in turn, while the daughter does).

Conventional male-oriented ancestry charts do not help much in identifying common ancestors between persons with identical or similar mtdna. This is because other carriers of the same mtdna that might link up to your lineage are not displayed and cannot be easily located in census databases, since in each generation their surname will change through marriage.

In most West European cultures (Spain excepted), the male dominance of inheritance and especially in passing on the surname to the children makes tracing the patrilineal line relatively easy. A man looking for y-DNA ancestors has to do no more than look for people with the same (or similar, in the case of alternate spellings) surname.

Tracing the matrilineal line is somewhat more difficult, although perhaps not quite as difficult as it may seem. In the last few years the availability of complete indexed British and US census records on ancestry.com has revolutionized genealogical research. It would seem that these records would not be of much help in tracing matrilineal ancestors, since a woman will have assumed her husband's surname on marriage and will 'disappear' from the records.

But in fact in a surprisingly high percentage of the cases, these records will allow you to trace back your line. This is due to the fact that the nuclear family living in a separate home is apparently only a brief phase of human civilization. Prior to the second half of the 20th Century, it was common for children to live on the farms or in the houses of their parents early in their life and in their children's later in life. Census records indicate a daughter-in-law, son-in-law, father-in-law, mother-in-law - and bingo! You've made the link to the next generation.

Also, computerized databases allow you to make searches on various criteria. If the first name of the married ancestor is unusual, you may still be able to find her in her premarital family without too much difficulty (e.g. searching for Artemisias born between 1882 and 1884 born in Ohio).

Outside of ancestry.com, the ever increasing open Internet resources, and the power of Google and other search engines, provide other powerful tools (if you are clever enough in your searches). You also have to try again every few months and using different search engines - kajillions of lines of new data are being placed on the Internet all the time.

Finally, there are only so many family trees. Once you have gone back a couple of generations, there is a good chance you may connect with genealogical work someone else has already done and is available on the Internet. Making this kind of connection can allow you to suddenly jaunt back generations to medieval England on one lineage. Of course the quality and reliability of some of these genealogies is unknown and sometimes almost impossible to determine. But it is a starting point, and more than you knew when you started!

That said, there comes a time when you have reached a dead end with available on-line records. The Internet will still help you, allowing you to find where the birth and marriage records you need to search through are located, and how to access them. In this further phase of your research adventure you may discover such gems as the French Canadian Catholic priests who kept meticulous records and continued to categorize or notarize women by their maiden name throughout all life events. If you cannot travel to where the records are, it is possible to hire local researchers to do the work for you… and these researchers can be located on the Internet as well.

Or you can shelve your work for now, upload your gedcom to the Internet, and wait for a few more years - when kajillions more records will be available on the Internet, and perhaps then you can make new connections!

For helping those tracing their matrilineal lines, a conventional ancestry chart like that shown above is not too useful. More useful is a matrilineal descent chart. This shows all of the female descendants of your most remote female ancestor. This should be accompanied by a list of the married and maiden names of those descendents. This will allow search engines to make the necessary link to find that common ancestor…

An example of such a maternal descent tree is provided here.

Here is an interesting, basic, 30 minute presentation on matrilineal genealogy from NEHGS. You have the option to skip ahead if you're impatient with the narration or have the sound turned down on your PC: http://nehgs.breezecentral.com/mothersmother.