I was attempting to explain to a brother who insists that African Americans are indigenous to the Americas that if this was true, our DNA would as dissimilar to continental Africans as the DNA of Blacks in Asia and Australia. I don’t know if he understood my point, which is that a separation of tens of thousands of years would have occasioned mutations that would have greatly differentiated us from our counterparts in Africa. We wouldn’t take DNA tests and have shared DNA with people from places like Ghana or Nigeria for instance.
Of course there are other elements of these arguments that are deeply flawed, but I found his perspective to be consistent with that of most people who I’ve encountered who believe all manner of conspiracy theories–1) documented evidence is fabricated by some seemingly omnipotent and hidden malevolent force, 2) unreliable and anecdotal sources are regarded as concrete evidence, and 3) a circular logic posits that a lack of evidence in support of the theory is evidence of the existence and scale of the conspiracy.