seedmagazine.com: by PZ Myers

The idea of humankind as a paragon of design is called into question by the puffer fish genome – the smallest, tidiest vertebrate genome of all.

When I mention the Japanese puffer fish, or fugu, to friends and students who are even slightly pop-culture savvy, I get a predictable response: That’s the fish that almost killed Homer Simpson! The fugu is an actual fish, and a beautiful little advanced bony one. Among its claims to fame is that it protects itself from being eaten by secreting a potent neurotoxin called tetrodotoxin that blocks nerve impulses and can kill a person in a high enough dose. That’s part of the reason humans eat it, though: If carefully prepared and not eaten in excess, it can provide a peculiar tingle to the lips—and the thrill of a little danger. In the well-known episode of The Simpsons, Homer discovers the joys of sushi, overindulges in poorly prepared fugu, thinks he has only a day to live, and typical sitcom hijinks ensue (ruined slightly for us science geeks, who know that fugu poisoning leads to rapid paralysis, which would tend to interfere with hijinks).

Fugu has another property of greater interest to evolutionary and developmental biologists, molecular biologists, and geneticists, though: It has an unusual genome. Through genomes, biology organizes genetic material into different forms of life; what we often find is that the real surprises are deep, hidden, and require a delicate sense of appreciation. In order to explain what’s unusual about the fugu’s genome, a comparison with our own human genome is in order. [ read more ]