There has been extensive DNA studied conducted on Amerindians thorough out the western hemisphere. Much summarized here
That is why the bom lands keep getting smaller and smaller while apologists try to weasel-word the clear teaching and understanding of smith and the founders of mormonism.
I am aware of that and the projects are outside of LDS.
That is why they are on excavation in Mexico so they can co-opt some poor hapless no nothing tribe.
You mark my words by the end of next year they will announce they have discovered their bloodline and will be from one of their digs in southern Mexico.