If you want to learn more about your family’s ancestry, you should begin with an ancestry DNA test. However, you can choose from various kinds of tests to ensure the accuracy of the results. You just need to learn more about genetics and what tests are the best ones to take. The following information can give you more insight into this type of testing process. A DNA-based test looks at a person’s genome to find a genealogical relationship in a family. The following tests are often used to learn more about an individual’s family history.
1. Autosomal DNA Testing
Autosomal DNA features 22 pairs of chromosomes that do not contribute to a person’s gender. Because the test does not rely on a 23rd chromosome, it can be performed on both men and women with the same outcome. Genealogical autosomal DNA testing reviews about 7000,000 single nucleotide polymorphisms (SNPs) or snips to find genetic variations.
Half of a person’s DNA comes from their father and mother. The further you go back in time, the less DNA is inherited from a specific ancestor – something to consider when taking this test. This means that you can only connect with relatives as far back as a third or fourth cousin.
The main use of autosomal DNA testing is to find out how closely related you are to another relative. This test is often used if you know little about your parent(s) and are finding it difficult to locate other relatives. Every DNA testing company that provides ancestry DNA test results uses autosomal DNA tests.
2. Mitochondrial DNA Testing
This type of testing is also called mtDNA and involves surveying the genetic material within a person’s mitochondria. Mitochondria are small components that are found inside each cell and which have separate DNA strands. The mtDNA is passed down from the mother and does not include the DNA from both parents. It does not change through the generations. In fact, the mtDNA may remain the same for several generations.
When this test is performed, the main DNA in a cell is ignored. The test examines about 16,500 genetic pairs, instead of the 3.2 billion pairs found in regular DNA. This test provides accurate results, but only on the mother’s side of a family. The test identifies how closely related you may be to a haplogroup, or a group of individuals with one common ancestor.
3. Y-DNA Testing – the STR Sub-test
The 23rd chromosome features two versions of chromosomes – X and Y. Whilst women have two X chromosomes, men have one X chromosome and one Y chromosome. Two sub-tests are conducted during Y-DNA testing. The first test is an STR test, or short tandem repeat test. This test classifies the DNA according to the frequency a genetic pattern repeat. If you are an adoptee, you will find this to be a useful test. There are valuable resources available at the CRI genetics website.
4. Y-DNA Testing – the SNP Sub-test
The second test is a single-nucleotide polymorphism (SNP) test. It works about the same as an autosomal DNA type test, but tests 30,000 SNPS instead of 700,000 SNPs.