Tuesday, May 12, 2009

Nature's gamble

In the days when few people lived to see old age even in the best of circumstances, Mother Nature apparently took an evolutionary gamble -- in the hope that the new human being would survive long enough to at least pass along his genes.

In Africa, a mutated gene in some persons distorts the shape of the red blood cells. This, for reasons too lengthy to explain here, helps to protect such a person from malaria -- an ancient, rampant killer on that continent. We call that mutation sickle cell anemia and we also call it a disease, an awful, painful disease. But malaria kills much faster than sickle cell anemia.

Today, I have learned about another one of evolution's trade-offs.

From wikipedia:

"It has also been hypothesized that the cystic fibrosis genetic mutation has been maintained in humans due to a selective advantage: heterozygous carriers of the mutation (who are thus not affected by cystic fibrosis) are more resistant to V. cholerae infections.[19] In this model, the genetic deficiency in the cystic fibrosis transmembrane conductance regulator channel proteins interferes with bacteria binding to the gastrointestinal epithelium, thus reducing the effects of an infection."

Cholera kills much, much faster than cystic fibrosis.

It makes one wonder how many more of these trade-offs have been made, how many more of the autoimmune diseases have a hidden silver lining in their dark cloud.

6 comments:

Lone Grey Squirrel said...

Absolutely astute observation. It is probably true of some diseases but still a lot of others are without any such silver lining.

Janice Thomson said...

Isn't it amazing how Nature/the body finds ways of coping with each generation of illnesses to protect the complete annihilation of the human species yet we constantly complain and destroy her in the process...

kat said...

very interesting!

Hi ECD :-) I am doing great, enjoying myself tremendously. Thanks!

heartinsanfrancisco said...

Wow. What an interesting post! I didn't know this.

My husband suffers from early-onset Alzheimer's and it's impossible to imagine a silver lining therein, but it would be nice to think so.

chipazoid said...

Lol, yeah we did a lot of that study in undergrad. I should dig up some of the case studies and let you know! Anyway just thought I'd drop by, I know I haven't been online for awhile. Hope you are well!

Eastcoastdweller said...

Thanks to you all for your comments. I appreciate each of them. And I am very glad to hear from You again, Adena, my first blog friend.