2/06/2006
Ancestry Tracing basics
Good article in NYT by Jennifer Alserver with basics about tracing your ancestry using DNA analysis:
The DNA tests have limitations, showing only small slices of genetic history.
Here is why: a popular test, the Y-DNA, analyzes the Y chromosome that is passed virtually unchanged for generations from father to son. The test, which can be taken only by men, examines just one branch of a family tree: the male line — a father's father's father, and so on.
Another test looks at mitochondrial DNA, a certain form that is passed from a mother to all her children. Both men and women can take the test, which aims to trace ancestors on a mother's side. But the test follows only the direct female line.
Both tests are used to determine if people are related, even through people who lived 500 years ago, or perhaps determine the country of their ancestors. No test can look at the DNA of a father's mother, for instance, or of a mother's father.
The tests generally work this way: A person orders a test online and receives a kit with toothbrushlike scrapers, collection tubes and instructions on how to take a swab from inside the cheek. The samples are mailed to a laboratory, where scientists analyze DNA markers, or genetic traits.
The results and samples, sometimes labeled with bar codes to protect identities, are stored for future tests unless customers request that they be destroyed. Consumers worried about privacy should ask questions of the testing company and satisfy themselves that the provider respects confidentiality.
DNA Kits Aim to Link You to the Here and Then - New York Times
The DNA tests have limitations, showing only small slices of genetic history.
Here is why: a popular test, the Y-DNA, analyzes the Y chromosome that is passed virtually unchanged for generations from father to son. The test, which can be taken only by men, examines just one branch of a family tree: the male line — a father's father's father, and so on.
Another test looks at mitochondrial DNA, a certain form that is passed from a mother to all her children. Both men and women can take the test, which aims to trace ancestors on a mother's side. But the test follows only the direct female line.
Both tests are used to determine if people are related, even through people who lived 500 years ago, or perhaps determine the country of their ancestors. No test can look at the DNA of a father's mother, for instance, or of a mother's father.
The tests generally work this way: A person orders a test online and receives a kit with toothbrushlike scrapers, collection tubes and instructions on how to take a swab from inside the cheek. The samples are mailed to a laboratory, where scientists analyze DNA markers, or genetic traits.
The results and samples, sometimes labeled with bar codes to protect identities, are stored for future tests unless customers request that they be destroyed. Consumers worried about privacy should ask questions of the testing company and satisfy themselves that the provider respects confidentiality.
DNA Kits Aim to Link You to the Here and Then - New York Times
