The Mystery of Metamorphosis: A Scientific Detective Story by Frank Ryan
I've always been fascinated by metamorphosis. Who isn't? How the heck can something go to bed a grub and wake up as a sexy butterfly? Does it remember any of its former life? How about the transition, the horror story where the grub melts into goo and transforms? Was Larry Niven on to something in Draco's Tavern where he suggested caterpillars postpone metamorphosis as long as possible because only in their juvenile state can they live sentiently for years, whereas as adults they turn into sex-crazed imbeciles that live only a week? How did forces of evolution come to design land-based and marine-based metamorphosis? It is a freaky life-strategy. This book champions a theory as to how, a really cutting-edge, crazy theory that, when published in a scientific journal, prompted 99% of all other scientists to call that journal the new National Enquirer.
Hybridization as evolutionary tool sounds Lamarckian, right? Right. I was excited about the prospect of this theory, having recently learned about horizontal gene transfer, and ready to hear Darwin awhirlin' in his grave. Now I've read the book, the theory does ask interesting questions, but it doesn't stand up to scrutiny. The evidence is circumstantial at best (e.g; the Cambrian explosion happened! One of the Cambrian fossils (Nectocaris pteryx) looks like a hybrid! QED Hybridization was a factor in the Cambrian explosion!) At worst, the evidence isn't reproducible. A world-renowned marine biologist, who'd never done any molecular biology (genetics), noticed interesting things: 1) water-based reproduction is haphazard. Sperm floats around. 2) the larva of very different phyla look the same. One baby can start out bilaterally symmetrical and be a deuterostome, and either grow up to retain those characteristics or become radially symmetrical and a protostome. That's freaking weird stuff. It's so weird that other biologists have outright said that they refuse to consider marine larva while taxonomizing. But he, brave guy, hazarded a guess: maybe the little floaty larva stage was such a wonderful adaptation for dispersal that other organisms adopted it after they'd settled on an adult form. And, he thought, they probably did that via hybridization. So this fellow tried to create hybrids. He said he did so, a combination worm/ sea urchin. But a molecular biologist checked (a small percentage of) his hybrids and found they weren't; just a regular old sea urchin, known to be able to fertilize itself. Contaminated data! Ack! In 2010, a team of molecular biologists came out saying that, genetically, a sea squirt (tunicate) does look like it shares half of its genes with chordates and the other half with nematodes and that there could have been a HGT event that caused it. But, based on the almost-nothing I know about genetic assignment based on molecular biology, that sounds iffy. We share 60% of our genes with fruit flies, but I don't think there was a hybridization moment there.
That said, I learned a lot about metamorphosis. But I doubt I will pick up another Frank Ryan book. Guy can't edit. Most of his 13-letter words are frosting.
Hybridization as evolutionary tool sounds Lamarckian, right? Right. I was excited about the prospect of this theory, having recently learned about horizontal gene transfer, and ready to hear Darwin awhirlin' in his grave. Now I've read the book, the theory does ask interesting questions, but it doesn't stand up to scrutiny. The evidence is circumstantial at best (e.g; the Cambrian explosion happened! One of the Cambrian fossils (Nectocaris pteryx) looks like a hybrid! QED Hybridization was a factor in the Cambrian explosion!) At worst, the evidence isn't reproducible. A world-renowned marine biologist, who'd never done any molecular biology (genetics), noticed interesting things: 1) water-based reproduction is haphazard. Sperm floats around. 2) the larva of very different phyla look the same. One baby can start out bilaterally symmetrical and be a deuterostome, and either grow up to retain those characteristics or become radially symmetrical and a protostome. That's freaking weird stuff. It's so weird that other biologists have outright said that they refuse to consider marine larva while taxonomizing. But he, brave guy, hazarded a guess: maybe the little floaty larva stage was such a wonderful adaptation for dispersal that other organisms adopted it after they'd settled on an adult form. And, he thought, they probably did that via hybridization. So this fellow tried to create hybrids. He said he did so, a combination worm/ sea urchin. But a molecular biologist checked (a small percentage of) his hybrids and found they weren't; just a regular old sea urchin, known to be able to fertilize itself. Contaminated data! Ack! In 2010, a team of molecular biologists came out saying that, genetically, a sea squirt (tunicate) does look like it shares half of its genes with chordates and the other half with nematodes and that there could have been a HGT event that caused it. But, based on the almost-nothing I know about genetic assignment based on molecular biology, that sounds iffy. We share 60% of our genes with fruit flies, but I don't think there was a hybridization moment there.
That said, I learned a lot about metamorphosis. But I doubt I will pick up another Frank Ryan book. Guy can't edit. Most of his 13-letter words are frosting.