The standard dna test offered by Familytreedna, the one that we have used for Catley tree
testing (13 different trees done and 9 matches found) uses the standard Y DNA evaluation
which as you will recall, is limited to male donors only.
However, since 2010 there has been another test available called Autosomal Chromosome
evaluation which is marketed as an alternative new source of evidence for genealogists. I
do not understand the details of how this new test works but in essence it seems that the
new test looks at some 700,000 genetic markers spread across the autosomal chromosomes of
a donor sample and compares them with the same data for other individuals within their
database. Where identical fragments of DNA of a significant size, are found in identical
locations on the same chromosome, when comparing two people, then it can be deduced that
these two persons are genetically related.
The extent and similarity in terms of size and location of any identical fragments can be
used to deduce the closeness of that relationship with an acceptable level of probability.
This test can be used by both women and men and is thus not constrained to the male line
as in Y-DNA testing. The conventional wisdom is that one can generally identify a
relationship as far away as a 5th cousin and sometimes even further.
If you wish to know more,then have a look at the FTDNA web site under the heading :-
"Family Finder"
Tim