The Y-DNA test looks at some of the DNA which is contained in the chromosomes that parents pass on to their children. Half of a child's chromosomes come from the father; half come from the mother. Only males have Y-DNA, which is passed from father to son, virtually unchanged. Through DNA in the chromosomes, parents pass on a molecular record of the child's ancestors. Although 99% of DNA is identical in humans, it is the other 1% that makes each of us unique. Through thousands of years, and hundreds of generations, a few mutations occur. These mutations are passed from father to son and differentiate families with the same surname. The differences are called haplotypes. The mutations measured in the DNA tests occur in what is called "junk DNA". The purpose of the markers in "junk DNA" is not fully understood; "junk DNA" has no known medical function although recent research shows it may have some regulatory impact on the genes. 

DNA tests must be used in connection with genealogical research to help identify relationships. If two results are compared and the results differ, then the two are not related. If the test results are identical, then the two share a common ancestor. Family Tree DNA will provide a prediction as to how many generations there are to the most common recent ancestor. Since this prediction is only an estimate, it is recommended at least 37 markers be tested to produce the most meaningful results. The actual connection between the two participants will rely on standard genealogical research and comparison of the family trees.

To order a test kit, click on the box above "Join Request." You will be taken to the page where you will be able to order a test kit. By joining the surname group, you will receive a reduced cost on the test kit. Since only men have Y-DNA, women interested in the Rorer/Rohrer surname project should ask a male relative with the surname to submit a sample. In order to join the group, please submit a list of your known Rorer/Rohrer ancestors.

Family Tree DNA offers two other tests. One is for the mitochondria or MtDNA.  The mother passes her MtDNA to her offspring, both male and female. Only the female passes it on to the next generation. Thus, MtDNA test shows the mother's mother's line. An MtDNA test is not as useful as the Y-DNA test for genealogical purposes. This is because the MtDNA mutates much more slowly than does the Y-DNA and because females do not usually hand down their surname to their daughters. Therefore, it is difficult to differentiate family groups by surname studies as is done with Y-DNA surname groups. Some adoptees and others, however, have found the test useful for determining whether a particular woman is possibly a family member.

The autosomal, or Family Finder, is another test offered by Family Tree DNA. This shows all the lines of an individual. Since at each generation, only 50% of an individual's genetic material is passed on to the offspring, the test is most reliable to the third cousin level. It is up to the participant to find matches and exchange information to determine their common ancestor.

Participants are welcome to order these other tests through the group surname project. Please remember, though, that the focus of this project is on the Y-DNA tests to illuminate family groups of those with the surname Rorer and its variations.

The surname group has a General Fund to aid those whose lineage may be of interest to the surname group but whose funds are limited.  Any size donation is greatly appreciated! If you choose, you can donate anonymously. Thank you!