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| DNA is the blueprint from which your body is built. The DNA of all humans is virtually identical and is the reason we have five fingers and toes and two legs and arms. It determines where those parts are fastened to our body and where our vital organs are placed. The very slight differences in our DNA determine the slight differences we see in each other -- whether we're short or tall, the color of our eyes and hair, the size of our feet, the shape of our sinuses, tongue and voice box which determine how our voice sounds, etc. |
We use these slight differences to tell one another apart, and we use the slight differences in our DNA to tell which family groups we belong to.
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There are four basic types of DNA used in genealogical research
- Three of them are located within the nucleus of our cells:
- Autosomal DNA -- 22 pairs of rope-like chromosomes. This is "recombinant" meaning a person gets a portion of it (typically 1/2) from each parent.
- Y-chromosome DNA -- 1/2 of the 23rd pair of chromosomes. This is passed from a father to his son.
- X-chromosome DNA -- like the autosomal, it is recombinant, but men do not get any of their X-chromosome from their fathers, so it provides a "lopsided" view of one's ancestry as opposed to autosomal DNA.
- The fourth is located outside the cell's nucleus -- Mitochondrial DNA. It comes only from the mother and is passed to her children.
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| We inherit random portions of our autosomal DNA from both of our parents, whereas the Y-DNA and mtDNA come from only one parent. |
| In traditional research, we search for something unique that can be used to define or identify an ancestor. A bunch of papers mixed together in a box at the courthouse is meaningless without a name or place or some other tidbit of information that we can use to help us in our research. |
| DNA is the same way. We need to be able to identify which parent contributed it if it's to be used to trace ancestry. Autosomal DNA can become like the mess of papers in the box -- it has been randomly mixed up and it is difficult to tell which parent contributed it. It's of little use in any research beyond three or four generations, five at most. On the other hand, mtDNA does not share anything with the father's DNA, so it represents the mother's lineage (maternal line). The Y-DNA does not share anything with the mother's DNA and it represents the father's (paternal) line. The fact that both mtDNA and Y-DNA are passed unchanged from parent to child make them ideal for tracing ancestry. The slight changes which occur when a mistake is made in copying the DNA from parent to child become the distinguishing characteristics for family branches. |
| Unfortunately mtDNA changes too slowly to provide very much useful data for tracking recent ancestors. It is better suited to researching ancient ancestral ties. Y-DNA changes more rapidly and has become the standard vehicle for genealogical DNA research. |
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| THE CLOUD FAMILY ASSOCIATION, Inc. |
| The CLOUD FAMILY ASSOCIATION (CFA) is a registered non-profit
corporation devoted to the collection and preservation of information
about the various branches of the Cloud Family, past and present. The
files of the Association are organized to provide a clearing house for
Cloud information and a major goal is to encourage people to share their
family information with the Association and with others interested in
the family. The association publishes the
CLOUD FAMILY JOURNAL (ISSN
0883-0940) quarterly to make this information, along with data from family
sources and public documents, available to interested persons. |
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| The CLOUD FAMILY ASSOCIATION
-- Making friends, finding lost cousins, preserving our heritage. |
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