Wednesday, February 6, 2008

Behind Blue Eyes

I found this article in the newspaper today and think it's the coolest thing I've read recently:

Researchers in Denmark have found that every person with blue eyes descends from just one "founder," an ancestor whose genes mutated 6,000 to 10,000 years ago. Before then, everyone had brown eyes...

Eiberg's team tested 155 blue-eyed people from Scandinavia, Turkey, Jordan and India, looking to see whether they had similar DNA sequences... To their amazement, they found that each individual had identical DNA sequences in that region of that gene, an indication that the original mutation happened recently enough that it hasn't had time to change.

For those of you who don't know, getting blue eyes comes from inheriting two recessive genes that determine the amount of melanin in your genes. That is to say, if you get the gene you're born with brown eyes (the default), but if you get the recessive gene from both parents then you get blue ones (if you have green it means you only have some melanin, but not enough for brown). According to the study, what ended up happening was two people in the Black Sea area a few thousand years ago had the gene through random mutations and had the first blue-eyed baby, and those genes ended up propagating to the estimated 300 million people who have blue eyes today.

Speaking as someone who has very deep blue eyes, I think this is pretty sweet because I now know I am related to Frank Sinatra, Jodie Foster, and a whole bunch of Scandinavians. (Anyone else?) It's always nice to know a little bit more about where you came from.

3 comments:

Linda said...

Because I'm a bio dork, I looked up the gene expression difference between blue and green eyes. Eye color is actually dictated by multiple genes, although blue can apparently be explained by one gene, as they just found out. As the article states, blue eyes are caused by a mutation that turns off the gene that produces melanin for brown eyes. Green eyes are created by a different gene. The melanin gene is switched on, but its expression is lower, so you end up with green irises.

Of course, this is way oversimplified because there's blue-green, grey, etc color eyes. I'm not sure of the mechanisms of those, but it would be an interaction between all the various eye color genes.

Lar said...

So...If i could come up with some sort of...something..that attacked people w/ that DNA sequence...why....I could...RULE THE WORLD!!! MWHAHAHAHAHA...
sorry...i mean..umm...good for you all. well done

Kurt M. Weber said...

Does this mean that the last girl I dated and I were in an incestuous relationship?