Biogeographical Ancestry

Until recently, written and oral histories were the only clues to our geographic ancestry. Most of us could only hope to learn about our ancestors from a generation or two ago. DNA testing for ancestry has made it possible to discover our geographic origins over thousands of years. The reasons for undergoing a DNA ancestry test are unique and varied. Some of these include:

• desire of adopted individuals learn about their true ethnicity and geographic origins
• confirmation of previous genealogical study results
• curiosity about heritage and personal geneaolgy
• reclaiming history and identity robbed from people of African descent during times of slavery
• validating eligibility for government entitlements, such as Native American Rights.

What to Expect from Ancestry DNA Testing

Testing DNA ancestry is an easy and painless process. Since every cell in your body contains your unique DNA fingerprint, a gentle swab of the inside of the cheek is all that is needed to collect a DNA sample. You can order a testing kit from one of the many DNA ancestry sites online and mail in your sample. Your geographic history can then be tracked online.

You may also choose to visit your doctor or a DNA lab for testing, and discuss results in a more personal setting. Expect to pay between $100 and $400 for a home DNA test. Costs vary at individual labs and medical offices if you choose to test in person. It usually takes one to two months to receive results.

In either case, DNA ancestry test results can determine:

• accuracy of family tree research
• clues about ethnic origin
• if a person is related to others with the same surname
• if two individuals are related
• probable geographic ancestral origins
• whether two people descend from the same ancestor.

DNA ancestry testing cannot recreate your entire family tree or give any conclusive information about your medical future.

Understanding Ancestry DNA Testing

Genetic information is passed virtually unchanged from parents to children. Over many generations, genetic changes, or mutations, occur. While some of these changes can cause medical problems, most are harmless.

These mutations, called markers, help trace human origins and migration patterns by comparing individual markers with those in genetic databases. By testing for as many as 175 markers, an ancestry DNA search can determine the probability of your origins in four major historical population groups:

• Africans: Sub-Saharan Africa is the ancestral home of all humans.
• East Asians: This group includes those from China, Korea, Pacific Islands, Japan and Southeast Asia.
• Indo-Europeans: This group includes individuals from Europe, India, the Middle East and Pakistan.
• Native Americans: This group includes those who migrated from Asia to live in North and South America.

Types of DNA Testing for Ancestry

An ancestry DNA search can include many different types of genetic tests. Two of the most popular DNA tests for ancestry are:

• mtDNA Tests: Mitochondrial DNA, or mtDNA, is passed from mothers to children and comes from a cell's cytoplasm, rather than its nucleus. Mitochondrial DNA tests help trace maternal ancestry for both men and women.
• Y-Line Tests: These tests use genetic material from the Y-chromosome, which is passed only from fathers to sons. Y-line tests can trace paternal ancestry in men only.

Resources

Genelex Corporation. (2008). Ethnicity DNA Testing. Retrieved September 9, 2008, from the Genelex Web site: http://www.healthanddna.com/ancestry/ethnicity-dna-testing.html

MacNeil/Lehrer Productions. (2008). Q and A with African Ancestry. Retrieved September 9, 2008, from the Online News Hour Web site: http://www.pbs.org/newshour/indepth_coverage/science/dna/qanda.html

The Generations Network. (2008). From DNA to Data Learn How We Get Results From A Cheek Cell. Retrieved September 9, 2008, from the Ancestry.com Web site: http://dna.ancestry.com/dnaScienceBasics.aspx