Adoptions.
That is a broad subject. And the farther back in time the adoption (formal or informal),
the harder it is to determine the when and where such occurred.
In this day and age with science technology, one can have a surrogate birth mother whose
ova and sperm come from others, or even two parents of the same sex, of which only one or
none that provided biological material. The combinations are numerous.
Add in *an opps* and other mistakes from both males and females that create unintended
biological offspring.
Then we have adoptions in the more traditional sense whether it was done formally or not.
And we have children raised in a family due to rape or incest.
Complicate the issue with children of a previous marriage assuming the step-father surname
and we have an amazing mix.
My father adopted my mothers first child and raised another child caused by a rape. He
loved those two children like his own and to me they were just my sisters.
You have the traditional paternal testing that uses autosomal DNA (atDNA) markers to
compare parent and child. This has been around for over two decades and works very well.
It is very similar to the CODIS markers used to identify unknown people, remains and helps
solve crime.
When a parent is unwilling or deceased there are other options depending on the
situation.
Continuing with atDNA, there are tests such as Family Finder and the Ancestry DNA test
that can help determine genetic relationships. We share half of our chromosomes from each
parent, a quarter from our grandparents and so on back in time. Determining related or
shared genetic markers can provide the relatedness between two testers. This is a lot
easier with a chromosome browser used with FTDNA and other atDNA software. Generally
speaking the closer the relation is better understanding there is about 5 generation limit
back in time.
For females there is the X-STR test. Two sisters can compare results and determine whether
or not they are full or half siblings or not related at all.
For males there is Y-DNA testing that allows brothers, male first cousins and such
determine whether they have a common genealogical and genetic ancestor.
What DNA testing is best is based on the circumstances. If someone has a direct question,
please contact me off list and I will do my best to help out.
I hope this helps.
John R. Carpenter
La Mesa, CA USA
Carpenter Cousins Project
http://carpentercousins.com
Carpenter Cousins Y-DNA Project
http://www.carpentercousins.com/carpdna.htm
Carpenter Cousins Y-DNA Project lineage page
http://www.carpentercousins.com/generallineage.htm