Genetic genealogy is quite confusing but I think it is worth it. I haven’t tried it yet, but I am looking into genetic genealogy testing at the moment, so I thought I would share my findings with you. Many companies are doing DNA testing, including The Genealogist, Ancestry and Find my past.
What is genetic genealogy testing and what can I find out from it?
Genetic genealogy is the use of DNA and your traditional family tree. We have 23 pairs of chromosomes, all of which can help us find more about our ancestors. 22 are autosomal chromosomes, and one is our sex chromosomes with XX being females and XY being male.
Genealogical DNA testing first became available in 2000 with the launch of Oxford Ancestors and Family tree DNA. There are now many different companies all involved in the tests. By the beginning of 2013, an estimated 2.5 million people around the world had paid for a consumer test.
What are the Y chromosomes?
The Y chromosomes contain the male information, and if you are a male, you will have all the data from your father, his father and much further passed to you. However, a woman does not have this information. There are ways to get this though. If you have a brother it is quite simple, get him to do the test. If not, to get the male information you will need a male relative such as your father or paternal uncle or paternal nephews. Because the Y chromosomes are passed from father to son the same as surnames, it is a useful test to see if similar surnames are related.
What are the mitochondrial DNA?
The mitochondrial DNA is the genetic information that is passed from a mother to her children, which allows you to trace a direct maternal line. Although it is passed to both sons and daughters, only daughters pass it on to future generations. The mitochondrial DNA is from mitochondria cell structures. The information preserved about female ancestors may have been lost due to the fact mothers surnames are generally not passed down.
What are the Autosomal DNA?
Many DNA tests for family history focus on autosomal DNA. This test will give you more information about your parents; grandparents and so on. You can find living relatives on your branches connected to the last five generations. You can also find out your exact ethnic makeup, usually by percentage. If you use a company, who display a website with results, if you permit, you can find other people who have also had a DNA test and match your DNA. These are people with who you share a common ancestor within the last five generations. Usually the names and email of the people you pair with an estimate of how close you are related along with any genealogical information they have uploaded to attach to their DNA result. This usually ends up with someone else to research with and sometimes those brick walls breaking down. Autosomal chromosomes are the important ones as they are a genetic record of our ancestors. Before you are even born the chromosomes from your parents, combine to create you, a genetic mix of both your parents. Your mothers DNA was a mix of her parents and your fathers a combination of your paternal grandparent. The combination of chromosomes means your DNA is a mixture of all your ancestors. The markers on these autosomal chromosomes are needed to trace your family tree and its branches.
What is DNA Adam and Eve?
Everyone living today shares the same female ancestor, who lived in Africa an around 200,000 years ago. Men also share the same male ancestor, who many experts believe lived roughly around the same time. These ancestors are known as “Y-Chromosomal Adam” and “Mitochondrial Eve”. These were not the only people in the world; it’s just that genetically their lines are the last surviving.
What is a genetic tree?
The phylogenetic tree signifies the evolutionary connection of species thought to have a shared ancestor. Human beings represent one branch of this tree, which was built on DNA and predominantly SNP markers, which are small variations or mutations in the DNA that happen naturally over time.
Both the Y-DNA (paternal line) and mtDNA (maternal line) have their branches on the human genetic tree. ‘Y-Chromosomal Adam’ and ‘Mitochondrial Eve’ appear at the top of the tree, which then filters down to show the different genetic groups (haplogroups) descended from them.
Y-DNA tree has 18 branches, known as ‘Y-DNA Haplogroups’, which are called A to R. Every haplogroup also has several subgroups, which are called by a mixture of letters and numbers.
MtDNA tree has 26 main branches, known as ‘mtDNA haplogroups’, which are called A to Z. Like the paternal line, each mtDNA haplogroup has further subclades, which are again represented by numbers and letters. Everyone in the world is descended from one of these mtDNA haplogroups.
Haplogroups tell us where we are in the human genetic tree and also tells us to which ancient family clan we belong. As each group resulted from mutations (known as SNP’s), all people from the same clan will have the same variations.
What has this got to do with my ancestry?
Once you have identified your haplogroup, you can look into your deep ancestry and can find your migration route out of Africa. You can also link with others who you share ancient ancestry. These are people you may be able to connect with on your traditional family tree.
For more information see https://www.dna-worldwide.com/blog/190/understanding-haplogroups-what-can-they-tell-us-about-our-past (like I did.)
Can I find other DNA trees?
The phylogenetic tree of Y-chromosomal haplogroups, popularly known as the Y-DNA haplogroup tree (phylogenetic tree of Y-chromosomal haplogroups), is preserved by a volunteer crew of researchers at the International Society of Genetic Genealogy.
With the knowledge of your placement on the Y-DNA or mtDNA tree, you can find the genealogy of the patrilineal or matrilineal line a lot further than an old-style paper trail. It is even possible to make inferences about the geographical origin of your patrilineal or matrilineal line ancestor.
The Genome Reference Consortium maintains the reference assembly of the human genome. The GRC tracks issues relating to the Y chromosome such as gaps and errors in the sequence. Details can be found here. The GRCh37 build of the Y chromosome has a length of 59,373,566 base-pairs, but only 25,653,566 base-pairs are positioned. Build 38 (GRCh38) was released on 24 December 2013.
DNA trees can take us back to DNA Adam and DNA Eve. I would personally like to see where my DNA takes me and I am going to look at the best deals out there. I think I will benefit immensely from this information and would love to find more family members out there who are actively researching their family history. This has to be the next step for me, and possibly you too.