It is a matter of where the burden of proof legitimately is, and what evidence you need to bring. If you think humans were blocked from access to North America

It is a matter of where the burden of proof legitimately is, and what evidence you need to bring. If you think humans were blocked from access to North America, you need a mechanism to have blocked them, and evidence for it. We know that the fossil record is absurdly thin, and get our noses rubbed in it each generation, but seem never to learn better.