Understanding Genetic Genealogy

My goal is to provide a basic understanding of genetic genealogy. I know biology and genetics can be boring to anyone not interested science. Now I know you wished you stayed awake in biology!

What is DNA? DNA or Deoxyribonucleic Acid is the name of the molecule that carries the genetic information for reproduction of all living things. It has a double helix structure and located in the nucleus and small amount of the mitochondria of a cell. The nucleus and mitochondria are organelles (little organs) in a cell. You body consists of millions of cells.

DNA molecule

Human cell: pink center is the nucleus and pink hot dog shapes with mustard are mitochondria

Okay now... what are chromosomes? A chromosome is located in the nucleus and mitochondria of a cells holds protein and DNA. All humans without any genetic abnormalities has 23 pairs of chromosomes in the nucleus.

National Center for Biotechnology Information (US).

Bethesda (MD): National Center for Biotechnology Information (US); 1998-.

At this time there are 3 tests for genetic genealogy:
1.       autosomal DNA represents the 22 non-sex determining chromosomes in an individual
2.      Y-chromosome DNA represents the sex chromosome present in males
3.      mitochondrial DNA represents the maternal (from the mother) only DNA in a man or woman. Unlike the DNA in the nucleus it does the same amount.

In finding Frank Brumfield, the Ancestry.com autosomal DNA test was used in conjunction with the family tree or pedigree. Below is a chart of the percentage of DNA that is expected to be transferred at each of Frank Brumfield's descendants.

	Percentage of DNA	Generation
Frank Brumfield	100%
Child	50%	First generation
Grandchild	25%	Second generation
Great- grandchild	12.5%	Third generation
Great-great-grandchild	6.25%	Fourth generation
Great-great-g- grandchild	3.12%	Fifth generation
Great-great-g-g- grandchild	1.56%	Sixth generation

--- The Tree Gardener