I have DNA matches to people from JSD down (children, grand children etc) but not to Jacob.
I have always believed and that book with a list of Jacob's children seems to agree, that Jonathan the father of JSD is NOT a son of Jacob.
My DNA matches show that I am related to the Downers in Essex MA NOT Germany.
if anyone has done autosomal DNA and is related (and preferably has matches to Jacob Downer or that line further back (in Germany) Please contact me.