Genetic Genealogy

FTDNA Pedigrees

Brouwer Male Lines

DNA Project Results as of 02/11/2008

     There are currently two types of genetic testing available to the genealogist.  Y-DNA testing analyzes the male Y chromosome and mtDNA testing analyses the mitochondrial DNA.  I'll discuss Y-DNA testing since that has the most relevance to genealogical research.  Y-DNA testing provides clues about the male or surname line and provides a link from son to father to grandfather back through time.

     I'm giving a very straightforward explanation of how Y-DNA testing works.  If you'd like a more detailed explanation, check out the links page for additional sites.  Every male has one Y chromosome and one X chromosome.  Each son normally inherits an exact copy of his fathers Y chromosome.  Occasionally, a mutation will occur and the sons Y chromosome will be slightly different than his fathers.  By tracking these changes, it's possible to tell who is related to whom and approximately when they had a common ancestor.

     When you have your Y-DNA tested, the testing company sends you a swab to run around your cheek to gather a few cells.  There is no pain or blood.  You return the swab to the testing company and they examine your Y-DNA for certain markers.  Markers are just specific locations on the Y chromosome that contain a certain "value".  Testing is currently available for 12, 25, 37 or 67 markers.  The more markers tested, the better the differentiation between individuals.  The testing company will provide the individual with the values of the markers tested and then these markers can be compared to other males, typically with the same surname.  Surnames only became common in the 17th century so it's possible you could have a common ancestor with a male of a different surname.

     Here's an example of how it works.  A father has two sons and one son has a mutation at one of the markers while the other son inherits an exact copy of his fathers Y chromosome.  Now the same marker has a different "value" in each son.  The son with the mutation will pass his Y chromosome with the mutation on to his son and from that point on, it will be possible to tell which son you are related to depending on the "value" of the marker present in your Y chromosome.  As time goes on, more and more of these mutations occur and it's possible to figure out where you belong in the male family tree by the "values" of your markers.  This is why it's important to have a large pool of men participate in the Y DNA project.  As more branches of the family tree are  present in the pool of men tested, it becomes easier to place yourself in the tree based on the "values" of the markers you have in your Y chromosome.  A twelve marker test is all that should be necessary to indicate that a man is descended from Adam Brouwer.

     The Brewer DNA project has currently identified three main Brewer progenator groups and a number of smaller ones.  The main groups are Adam Brouwer of New Amsterdam, Jan Brouwer of New Amsterdam and George Brewer (husband of Sarah Lanier).