Today we’re going to look into the last set of DNA that you can use in your research, Autosomal DNA. This is DNA which is inherited from the autosomal chromosomes. Humans have 22 pairs of autosomes and one pair of sex chromosomes (the X chromosome and the Y chromosome). Each pair of autosomes is inherited the same way.
For each pair of autosomes, you received one from your mother and one from your father. Before the autosomes were sent to you, they were randomly jumbled in a process called recombination. Your parents also received their autosomes from their parents who also recombined them. So, your autosomes are random mixtures of all of your ancestors autosomes. All branches of your ancestry contribute to your Autosomal DNA. Obviously, the more distant the ancestor is, the less you share with them. Closer relatives will share larger fragments with you compared to distant relatives.
For example, this chart below shows, on average, how much autosomal DNA you share with specific relatives:
This is the DNA that most places use to match you up with potential cousins using Relative Finder from 23andMe or Family Finder from Family Tree DNA. If you have shared genomes with people on 23andMe, you can go to “Ancestry Labs” on the menu and choose “Family Inheritance: Advanced” to see which parts of your autosomal DNA you share, if any.
GEDMatch.com can also compare your Autosomal DNA and show you, in great detail, where you match with other individuals.
I hope you learned something. Remember, DNA testing is much more useful with an already sourced genealogy paper trail. Otherwise it will be very difficult to see how you relate to your DNA matches.