Family members share DNA. Your DNA comes from your parents, who in turn inherited their DNA from their parents. Ancestry DNA testing can help you trace your ancestry and ethnicity back many generations.
ND
Everyone has two types of DNA — chromosomal DNA and mitochondrial DNA. Both types of DNA can be used to understand your ancestry and ethnicity.
Two Kinds of DNA: Chromosomal & Mitochondrial
How DNA Testing for Ancestry & Ethnicity Works
Two Kinds of DNA: Chromosomal & Mitochondrial
Chromosomal DNA is found in the nucleus of your cells and is organized into 46 chromosomes. Two of the chromosomes, X and Y, determine a person's gender. The other 44 chromosomes are non-sex chromosomes made up of autosomal DNA.
)
You inherit half of your non-sex chromosomes from your mother and half from your father. You also inherit an X chromosome from your mother. If you're a woman, you inherit a second X chromosome from your father. If you're a man, you inherit a Ychromosome from your father. Because only men have Y-chromosomes, Y-DNA testing can help you learn more about your paternal lineage: your father, your father's father, your father's father's father, and so forth.
Mitochondrial DNA, also called mtDNA, is found in mitochondria, which are cellular structures outside the nucleus. Mitochondria occur in the eggs of your mother but not the sperm of your father, so you inherit mtDNA only from your mother. Testing your mtDNA can help you learn more about your maternal lineage: your mother, your mother's mother, your mother's mother's mother, and so forth.
How DNA Testing for Ancestry & Ethnicity Works
In the laboratory, chromosomal DNA and mtDNA are analyzed in similar ways. The DNA is first isolated from the cells, then sequenced. A DNA sequence tells us the order of the bases (labeled A, T, C, and G) in the section of DNA being analyzed. These segments of DNA are called genetic markers or DNA markers. These markers make up our "genetic profile," which can be compared with other people's genetic profiles. When two people have the same markers, there is a strong possibility that they share a common ancestor.
Companies that offer DNA testing for genealogy may look at different genetic markers. They also have different databases that are used for interpreting your test results. Depending on the kind of information you're looking for, different genetic tests can help you learn more about your ancestry and ethnicity.
