I wonder if anyone's studied family connections of colonies vs old regions? Like for Americans, at some point all of their ancestors significantly detached the

I wonder if anyone's studied family connections of colonies vs old regions? Like for Americans, at some point all of their ancestors significantly detached themselves from their place of origin and relocated. For e.g. Europe some people definitely did that but not all and maybe not even most? I would expect Americans to have less of a familial social network in general, which could affect health and lifespan.