04 February 2009

Genetic Genealogy - Q&A Quick Reference for Newbies

Although my blog has covered most of the following information, having this quick reference to the basics of Genetic Genealogy for those new to this resource could be helpful.

What is Genetic Genealogy?

Genetic genealogy is the use of DNA testing to aid traditional genealogical research. Available to the public in 2000, it can help genealogists to go beyond where their paper trail stops. This is the most accurate tool a genealogist has.

What tests are available for genealogy purposes?

1. Y chromosome DNA (Ydna) – Only part of the Y chromosome is currently tested

2. Mitochondrial DNA (mtDNA) – Depending upon the company, sections of the mitochondria are tested up to and including the full mitochondria (Full Genome Sequence or FGS)

3. Single Nueclotide Polymorphism (SNP) – SNPs are particular markers in the DNA that only mutate once. These markers help geneticist determine the haplogroup (see below).

4. Autosomal (atDNA) – This area of our DNA recombines (re-mixes) giving a person traits similar to their parents or siblings. These markers not only determine the hair color, shape of the nose, etc., but they include information on our health.

These markers are not helpful for genealogy as they change with every conception, thus even siblings will vary from each other on the test. Continuity is needed for genealogical purposes. However, some companies do offer this test and state they can determine the percentage of ethnic groups in a person’s DNA. (See my blog on atDNA)

What is a haplotype?

The results of the DNA test gives each person a certain series of numbers, in the case of males and of letters in the case of females. This is a person’s genetic signature.

What is a haplogroup?

It is your twig on the world family tree, also referred to as the Phylogenetic Tree. In order to find a person who matches your DNA signature, they must also match your haplogroup.

Who can test?

Any living male can test their Y chromosome DNA (Ydna) to obtain a DNA signature (haplotype) for their all male line (top line of a pedigree chart). (Usually, the surname of the tester, unless someone in the all male line was adopted or changed the surname for whatever reason.) Males can also test their mitochondrial DNA.

Any living female can test their mitochondrial DNA (mtDNA) to obtain a DNA signature for their all female line (bottom line of a pedigree chart). This is their mother’s mother’s, mother, etc. lineage.

How can I test the other parts of my family tree?

If you are a female and you wish to know the haplotype (DNA signature) of your father, you must have a brother test for you or some other male along your all male line who is living.

For any lineage on a pedigree chart that falls between the top and bottom lines of that chart, a surrogate tester must be found. For example: If you wish the haplotype of your maternal grandfather, you must put him as number one on a pedigree chart and test someone living on the top line. In most cases the grandfather is not living, nor are his male siblings or father. Then you must trace an all male line to the present for one of his male siblings. If there are none living, then go back one generation to the grandfather’s father and bring those all male lines to the present and have someone test.

The same is true when testing any female, but you must bring to the present an all female line.

What do I do if there are no matches with my haplotype?

Genetic genealogy is becoming so popular that it is a matter of time before a match will appear. However, compared to the world population we have only begun. You have two choices:
1. Wait until someone tests and matches you.
2. Seek out people whom you think may match you and have them test. For example: If you find people with your surname in a county where your ancestors were, but you cannot connect them though a paper trail, bring down those male (if you want Ydna) or female lines (if you want mtDNA) to the present and convince the person to test. More information on this is in the archives of this blog.

What is a DNA Project?

With the better testing companies, there are various DNA projects. These projects each have one or more administrators who lead the project. Anyone who fits the project criteria may join. The administrators vary greatly in how they run their projects. Anyone can become an administrator, as well. The project is the “housing” area for people who fit the project criteria.

The price of a DNA test is cheaper when going through a project in the most reputable companies.

What types of DNA Projects are there?

This can vary from company to company, but the following are found in the most diverse companies:

1. Surname Project – only males can join

2. Geographical Project – some of these are for males only; some for females and others will allow both. You must fit the geographical criteria. Projects range from counties to countries to continents.

3. Ethnic Projects – these vary according to ethnic groups and can be gender specific

4. Haplogroup Projects – these are gender specific. One cannot join them until after testing as that is the only time you know your haplogroup.

5. Affiliate Projects – some companies allow genealogical societies to form a project. These societies can put the company logo on their website and earn a commission on any sales. Anyone can join these projects and as it would be extremely rare that matches occur, this is only temporary housing for the test results.

In some companies, a tester can join more than one of the above, and can move from one relevant project to another at no cost.

What do I look for in choosing a company for my test?

Consider these features and services when choosing a company:

1. the company has been around for quite some time and is well established
2. good customer service via phone and email; tester can call directly with questions
3. large database of testers. The more people tested the greater the matches.
4. large variety of DNA projects
5. online tutorials and Q&As
6. high level of quality assurance; do they strive for 100% accuracy
7. website for your personal information at no cost to you
8. email contact when matches are found; daily comparison to the database to find matches
9. test can be upgraded to higher levels and as progress is made in genetics
10. long storage of the DNA sample so future upgrades are possible

What questions do you have? Send them to: Aulicino@hevanet.com

©Aulicino, 4 Feb 2009

1 comment:

Anonymous said...

Your timing was fabulous! Last night I presented a lecture entitled "An Introduction to Using DNA in Genealogy". I have referred all attendees to your great summary. Thanks!