Genealogy Corner: DNA Part 1

Image of DNA Sequence Courtesy of Wix

By Charlie Fraser, CFSNA® Northeast Regional Commissioner and Board Member

How many of our want-to-be genealogists have ever run into a brick wall where there seems to be an end to all that hard work accomplished into your diligent research only to find no light at the end of the tunnel?

We need to thank science for their relentless work to officially complete the human genome project in April 2003.  The 13-year project into international scientific research was launched in October 1990 with the goal of mapping and sequencing of the entire human genome.  By the date of completion about 92% of the genome has been sequenced, providing the first complete sequence for human DNA.

The sequencing of the human genome holds benefits from molecular medicine, human evolution, forensic science to animal husbandry, bioprocessing, risk assessment, and many other fields of applied science.

For people who are interested in tracing their family roots, DNA testing has become a very valuable tool to assist people in finding those lost links in time.  DNA, unlike historical documents, cannot be altered other than through a process called mutation.  Therefore, it has become a means to assist in breaking down that brick wall. 

Human DNA contains 23 pairs of chromosomes from each of our parents for a total of 46 chromosomes in each cell.  Of the 23 chromosomes, 22 pairs are autosomes which are numbered 1-22 and the 23rd-chromosome pair consists of sex chromosomes.  The male can pass either an X or a Y chromosome to the fertilized egg, while the female contributes only an X chromosome. If the father transfers a Y chromosome to the egg, the result will produce a son, (XY) and if the father transfers an X chromosome (XX) the result will produce a female. Males determine the sex of the newborn.

So why is all this scientific jargon important to a person wishing to trace their roots?  Through DNA analysis, chromosomes can be compared with those of other individuals to find a common match between people.  This then becomes the reason that DNA testing has become such a valuable tool for reaching that long-last relative.

For the next several weeks, we will post additional information about DNA testing, so check back often.