LEARNING

Here's an interesting morsel of info that someone forwarded me today regarding the history of Cystic Fibrosis:

Scientists have recently made the hypothesis that cystic fibrosis dates back to a genetic mutation 52,000 years ago, well before any formation of civilization. After this, they questioned why it has been able to survive being eliminated by evolution. They found an answer in the fact that people with one gene for cystic fibrosis are more apt to survive cholera. The people with that trait have half the number of channels as usual and can produce enough water to flush out the toxins made by the cholera bacteria without causing the dehydration and salt loss that is the usual cause of death. Cystic fibrosis also seems to be more common in cooler areas, because people in hot climates would tend to sweat more and lose more salt (needed in the body) in their sweat. (taken from http://en.wikipedia.org/wiki/Cystic_fibrosis )