Down's syndrome happens when a human being ends up with an extra copy of chromosome 21 — three copies, instead of the normal two. But scientists say they might have found a way to make that extra chromosome functionally irrelevant. If they're right, it could lead to treatments that could someday reduce the symptoms of Down's. The trick is connected to another extra chromosome that the human body "turns off" all the time — the X. Women have two X chromosomes, of course, but only one ever gets to express itself
. Scientists put the same mechanism to use on chromosome 21
in petri dish experiments.
On the left is a picture of me with my bike, taken by my friend Laura Kling. On the right is the same image, as it would be seen by a person with protanopia — a relatively common (as in, still very rare) form of color blindness that affects the ability to see green, yellow, and red colors.
The Color Blindness Simulator will allow you to do this with your own photos.