Jamboree 2015

This past weekend was the annual Jamboree of the Southern California Genealogical Society. As usual, it was both educational and lots of fun. It is held every year the first weekend in June at the Burbank Marriott. For the past three years a special DNA Day has taken place on Thursday before Jamboree starts Friday morning.

The use of DNA testing in genealogy is becoming more and more popular. There are three different types of DNA testing useful to genealogy: Y-DNA, mtDNA, and autosomal DNA.

Y-DNA is inherited by males from their fathers who got it from their own fathers. Each male receives a complete copy of his father's Y-DNA although mutations occur at predictable intervals. It is those mutations that determine how closely two or more men are related.

mtDNA is inherited by all children from their mothers but can only be passed on by females. It is the least useful form of DNA testing because mutations are rare and a match between two persons  could be from a female ancestor from thousands of years ago. It can be used to disprove relationships but is harder to use to prove descent from a particular woman.

Autosomal DNA is the DNA inherited from both parents. Each person has two sets of 23 chromosomes, one set from each parent. Mothers give each child an X chromosome and fathers give their sons a Y chromosome and their daughters a second X chromosome. Each parent recombines the two sets of 22 autosomal chromosomes they received from their own parents into a unique new set of 22 chromosomes. Each child of the parents receives 50% percent of their DNA from each parent but no child receives exactly the same DNA from each parent (except identical twins). Autosomal DNA testing will find cousin matches on all lines and is the most popular and useful DNA test.