We yawn to cool our brains.
I dedicate this recurring feature to Sidney J. Harris (1917-86), a syndicated columnist who wrote for the Chicago Daily News back when I was in medical school. He was a wise man and a great writer, and among his proudest accomplishments was making Richard Nixon’s “master list” of enemies. My kind of guy.
Every so often he’d have a column titled “Things I Learned En Route to Looking Up Other Things.” It was a great potpourri of wry, interesting, often offbeat factoids that may or may not have been related to what he was researching. I’ll try to live up to his memory.
Estrogen was the first hormone. It’s over 500 million years old. All other steroid hormones – progesterone, testosterone, etc. – evolved from estrogen.
Now, before you go saying that “estrogen first” means women must have been around before men, consider this: in primitive fish, like the lamprey, estrogen directs the maturation of both sexes. That’s right…in the old, old days, estrogen put everyone in a mating frenzy. So there.