DNA testing as proof of kinship
I would like to comment on using DNA as proof of family relations... while DNA testing can definitely determine if two or more people are related, and approximately how closely related, it connot prove exactly the relationship of persons. As all male members of the same parents should have the same DNA markers as tested for genealogy purposes, there are some actions that can mutate a person's DNA.. one of the most common is exposure to several types of radiation.
Some scientist think that the different DNA types found (different races) came about by extreme radiation from beyond our solar system that bombarded different parts of the earth many thousand years ago.. which goes against the grain of persons that beleive in intelligent design.
But, Ancestry.com gives some hint as to the accuraces of their test in their FAQ as follows:
"A common application of DNA testing is in determining the paternity of a child for custody or inheritance. Results of a DNA Ancestry test can definitively disprove a genetic relation. A large number of mismatches between two test results reflects that the two participants are not directly related. A 100% match, on the other hand, cannot be used as legal proof of paternity, but can serve as a strong indication."
http://dna.ancestry.com/learnMore.aspx#markersTestedhttp://dna.ancestry.com/learnMore.aspx#markersTested
So, if two test are exactly the same, there is still no proof of the exact relationship... even from father to son.
We should use the DNA test as a 'strong' tool in our genealogy research, but always remember that it is only a tool, and not a given fact.
DNA testing is a very new scientific principle and labs will, without doubt, determine better ways of testing and converting the raw data into information that is useful for the layman.
bob