It isn't that surprising that the first mode of colonization occurred after the Penultimate glaciation 170-190 ka from an ice age limited population. This was curtailed by the Toba eruption 70,000 years ago which essentially reduced the population in Africa to an estimated 5,000 females which then expanded to repopulate the world at 50,000 years ago.
So I'd say the odds were in our favor to eventually find a common ancestor.
