A Little Autosomal DNA Help

The purpose of this post is to help those newbies out there to understand a little better how this autosomal DNA testing works. Now, granted there are plenty of blogs and websites out there that explain in great detail how it works but a lot of them are too greek for some folks to understand. So I am going to attempt to break this down in easy to understand laymans terms.

Each and every person who ever lived has two different sets of chromosomes and they are as follows:

1. Our Sex Chromosomes: The Y Chromosome is primarily male. Meaning no female has a Y Chromosome, it can only come from a Male. In spite of the fact that everyone has a biological father, only Males will get that Y Chromosome from their father, a female cannot.

As you can see from the graphics above a Male has one X and one Y Sex Chromosome. And a female has two X Chromosomes. The male gets the Y from his father and the X from his Mother. A female gets her Father`s X and her Mothers X.

There fore using standard DNA testing in where one evaluates the Y and or the Mitochondrial (MtDNA) those results will go in a straight line. When we look at the Y DNA of the male it will go from the man to his father, to his grandfather, to his great grandfather and so on way back straight through that one Male line only! The same thing happens when a woman (or man) has their MtDNA tested, it will go from the female, to her mother, to her mother, to her mother and so on all the way back. It just goes straight down that one line.

2. Autosomal DNA Now aside from our sex chromosomes that give us our Y and MtDNA we also have 22 pairs of other autosomal chromosomes. Testing services such as 23andMe and Family Tree DNA`s Family Finder are tests that look at the Autosomal Chromosomes. All human beings have 23 pairs of Chromosomes, the 1 set of Sex Chromosomes we discussed above (XY or XX) and 22 other pairs of autosomal chromosomes.

Each of these chromosomes can come from anyone back in your family line. If you are a female, yes, you do get your fathers DNA through these Autosomal Chromosome pairs. This type of DNA does not go back from Father to his father and his grandfather and so on in a straight line. It can jump around anywhere in your family tree. Since the Y does not factor into your autosomal data then you do not have to wonder whether you can get your fathers DNA if you are a female. So, if you are female and have no recent male ancestor to test, you can still pick up some of the family through your fathers line by getting this type of DNA test done. The only difference I can see with getting a male to test is if you do so you will get your fathers Haplogroup, but other than that in my opinion for genealogical purposes, the autosomal testing is just as good. Besides Haplogroups are only indicative of lineage hundreds of thousands of years back. Autosomal testing deals with the more recent generations so it is good if you have been adopted or had a Non Paternal Event in your line because it can help you to discover your missing family members.

If you have any questions please ask away. I will do my best to answer them for you!