The purpose of this project is to establish as many DNA-connected Jordan lines as possible. During this Y-DNA testing process, many of the Jordan lines will be scientifically proven to descend from the same ancestors. It is our goal to build a large genealogical database to help all Jordan researchers prove their family connections -- not only now, but also for future generations.
It is necessary to have at least two participants from each documented and verified line in order to prove a group.
The Y-chromosome signatures change very slowly over time and the pattern is usually stable over hundreds of years. It is not expected to change more than once every 500 years, but for some unknown and unexpected reason, a mutation can occur without notice in any generation. Male relatives who have an uninterrupted male-male link between them will share the same, or very similar Y-chromosome signatures.
The Y-line is particularly useful when a connection between different branches of a family, perhaps with the same surname, is suspected but cannot be proven from written records. Using the Y-line, by comparing the Y-chromosome signatures, provides the answer.
A generation for genealogical purposes is usually considered to be 30 years, whereas a generation for DNA purposes is usually considered to be about 20 years.
There are some reasons that can cause a Y-line to be a non-match with a participants' previous non-DNA genealogical research and/or family tradition. These can include: incorrect paper genealogy research; adoption; rape; an unfaithful wife; or a child born out of wedlock.