Fill in the Blank...As soon as you find it.
According to a team of researchers from Copenhagen University, a single mutation which arose as recently as 6-10,000 years ago was responsible for all the blue-eyed people alive on Earth today.
The team, whose research is published in the journal Human Genetics, identified a single mutation in a gene called OCA2, which arose by chance somewhere around the northwest coasts of the Black Sea in one single individual, about 8,000 years ago.
The gene does not "make" blue in the iris; rather, it turns off the mechanism which produces brown melanin pigment.
But the real meat-n-potatoes part?
The finding that a rare mutation, probably dispersed in the rapid wave of colonisation that followed the end of the last ice age, highlights one of the great mysteries of human evolution.
Well, the article goes on to cite the "oddness" of Europeans - which is odd yet not altogether surprising, seeing as the source is a British daily.
But again, this builds directly on what I said earlier - that global trade had existed thousands of years ago beyond the bounds of what we had imagined, given the ginantic technological gap between now and then. But this only proves that slim-to-none leaves a little room for slim as well. Perhaps our scientists and researchers would do well to heed this in the future.