If you keep a vegetable garden, there’s a fair chance you’ll encounter a grisly sight this summer. Some poor caterpillar will be clutching a leaf, with the pupae of parasitic wasps sprouting off its back. It has just died in a most grotesque way. A wasp has zeroed in on the caterpillar and injected eggs into its body. The eggs hatched, and the larvae devoured their hosts from within, keeping it alive until they were ready to emerge.
Author: Lori Jia
Viruses have a special place at the Loom–they’re ubiquitous and have some pretty profound influences on the evolution of their hosts (including us). But a French scientist named Patrick Forterre wants to take it up a notch. He’s arguing that our very DNA is the creation of viruses some four billion years ago. It’s a controversial idea, but one that other scientists are definitely taking seriously. I’ve got the full story is here in today’s issue of Science, and here on my web site. For gorey details, see The Proceedings of the National Academy of Sciences for a paper by Forterre that surveys the scenario and the evidence it’s built on.
In case you were worrying that life on Earth would be wiped out by a catastrophic burst of gamma rays, rest easy. It turns out that our galaxy may not be a very good source of gamma ray bursts. I found this particularly interesting given recent speculation that gamma rays bursts might have triggered mass extinctions in the past. (News article here, original paper here.) The bursts are clearly catastrophic, but probably not close enough to Earth to cause much trouble.
Originally published May 10, 2006. Copyright 2006 Carl Zimmer.
It’s always great to hear senior scientists talk about the bad old days, when one computer could fill an entire room and no one could say what genes were made of. Eric Kandel of Columbia has been studying memory since the 1950s, and won the Nobel Prize in 2000 for his work. These days he’s observing genes switching on and off at the junctions between neurons. But when he started out, he had to content himself with sticking electrodes into crayfish (chosen for their fat neurons). To observe their neurons, scientists would hook up the electrodes to amplifiers and loudspeakers, and the crackle of nerves would fill the room.