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Posts Tagged ‘X chromosomes’

If you want DNA genetics it is not necessary to test every member of your family.   The Y-chromosome present in the cells of all males will yield results for all male members of your family.  Women lack the Y-chromosome and have only X chromosomes.  In this case, the mitochondrion of women is tested and findings apply to the female family members.

Popular media such as the television crime dramas show conclusive proof of DNA guilt or innocence.  DNA used for genealogy is not as fool proof.   Populations have been mixing since humans first left Africa 150,000 years ago, so while a DNA marker reveals a strong link of origin to a single group, it is not 100 percent guaranteed proof since no marker has been found to lie exclusively in one group.

Researchers believe every person on earth originates from only 100,000 early individuals and in some ancient way we are all related; your neighbor, your colleague, your best friend:  Even famous and infamous individuals like President Roosevelt or Henry VIII !

In spite of the scientific advances in DNA technology, the test is relatively simple.  A painless cheek swab is sent to a lab for analysis.  Technicians extract, amplify and analyze the cellular sample and then compare and match it to DNA samples from a database of other samples.  At this point they are looking to link it to a particular haplotype which is a grouping of closely linked genes.

When a person is found to share maternal or paternal ancestry lines with other people it is called lineage testing.  There is another kind of analysis called admixture testing which centers on 22 pairs of chromosomes not related to gender such as the Y which is exclusive to men and the X present in men and in women.

Regardless of the method you choose, DNA genetics will yield far more information about your ancestors than mere historical records can show.

With DNA testing for ancestry, the field of Genealogy has more tools than ever to discover your family tree.  Along with the genealogist research tools for digging deep into historical records and family history, you now have Genealogy DNA comparison to give solid evidence to your research.

A simple DNA test can start you on the road to discovering your ancestors from 10,000 years ago.  Men and women can both test their DNA to learn the origin of their maternal ancestry.  A specific kind of test called mtDNA or mitochondrial DNA, searches only the women along the line, no men.  Women and men both receive their mtDNA from their mother.

Men can learn the origin of their paternal line by testing their Y chromosome.  The Y chromosome test checks only the paternal line. Women do not have Y DNA and cannot be tested for their paternal line.  If they want to know their paternal ancestry they must ask a brother or their father or a male cousin to be tested.  This is one way to firm up the surname line of your ancestry.

Once the DNA sample is taken, the results will determine your haplogroup.  This is a set of a people with a common ancestor, often from 10,000 to 150,000 years ago, the time when it has been shown that humans evolved in Africa and then migrated around the world.  Men have both a paternal and maternal haplogroup; women have only the maternal haplogroup because they bear only X chromosomes while men have an X and a Y.

A fascinating result of the DNA test is to see where your ancient family members migrated across the globe.  You’ll see how mutations in early genetic lines affect your family too.   You’ll learn all the genetic influences in your ancient family tree.  You may have Asian influence you don’t know about or you may be related to Napolean or a U.S. President.   DNA testing for ancestry will provide knowledge about your unique family history you never thought possible.