First the news, in 2005, that all light-skinned people trace back to a single mutation that occurred during the first major "out of Africa" exodus of Homo Sapiens, sometime between 20,000 and 50,000 years ago.
Today researchers are reporting that all blue-eyed humans are descended from a single mutated forbearer. This common ancestor lived between 6,000 and 10,000 years ago.
I love it, I love it, I love it - white people are mutants, I always figured as much. (OK I'm being silly - we all originated in Africa, so of course our earliest ancestors were all brown-skinned. But it is extremely cool that scientists, using techniques like mitachondrial DNA sequencing, can trace back the process by which these changes in the human population took place.)