A further complication is that every discovery provokes new questions. The more we know, the more we do not know. To predict what lies ahead, we must often rely on guesswork. But the nature of our present ignorance points to problems science cannot avoid. The most obvious of these is the question of what happens in our head when we are thinking.
Nobody yet has a compelling answer for that.
People surmise, but no surmise can yet meet the tyrannical test that every assertion about the nature of the world must be proved by experiment or observation. The genes of the two groups differ hardly at all, but some of them are differently arranged. As a by-product, we shall be able to trace the migration routes of our human ancestors who emigrated from Africa and came to populate the surface of the earth. A half-century from now, we shall have a rich and authentic history of the human race. How life began is a grander question that will occupy most of the next century.