Sunday, April 15, 2007

The Reason for Diseases

Title: Survival of the Sickest: A Medical Maverick Discovers Why We Need Disease
Author: Dr. Sharon Moalem with Jonathan Prince

I listened to an interview with the author of this book on NPR and immediately ordered it through my library. I'm not at all up on medical jargon but I found it quite easy to read. This book is written so that it is accessible to the general public, extremely hard to put down, and quite humorous. That's hard to find in a non-fiction book, and I definitely say this one is a must-read!

Moalem discusses the reasons behind the development of certain diseases - or at least what he suspects are the reasons based on a standpoint of evolutionary biology. For example, diabetes - where the body keeps more sugar than necessary. This could be very beneficial in extreme cold because higher quantities of sugar lowers the freezing point of water. Thus, all this sugar could be keeping the body from freezing. Of course, this was only really important during the last ice age when humans also had brown fat, which converted any excess sugar immediately into heat.

Okay, that's my attempt at an explanation, but you really need to read the book to truly understand this stuff.

Some other fascinating tidbits include:
1. Wearing sunglasses makes you more likely to get a sunburn because your pituitary gland, which controls the melanin in your skin, gets its info about the amount of sunlight from your optic nerve. So if you're wearing sunglasses, your pituitary gland thinks, okay, not too bright out, so we don't need to produce as much melanin.

2. Want to increase your sex drive? Get herpes! Researchers are looking into the possibility that herpes might increase sex drives because it wants to increase the likelihood that it will spread from person to person.

You'll also be quite surprised by what some creatures go through to keep their species alive - or at least, I certainly was. There's a worm that lives in sheep and cattle livers. Its eggs get excreted in the animal poo and eaten by a land snail, where they hatch and are excreted as slime. Then that slime is eaten by an ant which winds up with a hatched worm in its brain. That newly hatched worm then manipulates the ant into the seemingly suicidal behavior of climbing to the tip of a blade of grass every night to be eaten by a cow or sheep - and thus start the process all over again.

Lots of fascinating stuff in this book, and the above is only a tiny part. This really is one of the best books I've read in a long time.

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posted by Kate at 4:23 PM


Blogger reyn said...

That's fascinating, but one has to wonder how many evolutionary missteps led to a species relying completely on four totally unrelated species for survival--and includes such complex behaviors as mind control!! I need to read that book and learn the ways of the worm...

4/18/2007 7:28 AM  
Blogger ~e said...

google finally decided that i really DID belong to blogger in a previous life, so...

this guy puts forth a lot of really interesting ideas about things that we would consider "diseases" today but that helped keep humans alive until at least middle age back in the day. I thought that his theory about iron and the plauge and so forth was pretty good, and the one about cholesterol and vitamin D.

Someone should have gotten him a better editor, though.

4/21/2007 10:24 PM  

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