Because that would mean two species of humans evolved separately on opposite sides of the earth.
So why, if they need to insist that only one race rose up, couldn’t it have risen here and migrated there? Maybe they done writ history bass ackwards. Adama. Red. Clay. Gee. Redmen. Cain’t have that, now, can we? Mus’ be black or you cain’t exist?
Gee fellas. Ain’t that racist?