Author: Lori Jia
Martin Schaefer, one of the scientists I wrote about in my recent post on autumn leaves, has joined the comment thread and kindly answered some questions about his work. Check it out.
Originally published October 20, 2006. Copyright 2006 Carl Zimmer.
Flowers, flagella, feathers. Life is rife with complex features–structures and systems made up of many interacting parts. National Geographic magazine asked me to take a tour of complexity in life and report on the latest research on how it evolved. What struck me over and over again was how scientists studying everything from bacteria to humans are drawn back to the same concepts–making new copies of old parts, for example, or borrowing parts of one complex trait to evolve a new one. And in each case, complexity opens up the way to diversity, because something many parts can be rearranged in many ways.
This fall we’ve had some rude visitors out by the front door. One morning a strangely foul smell wafted through the windows. When we looked outside for a dead animal, we found nothing. But we noticed some downright obscene growths foisting themselves out of the flower beds. Thus I got my first introduction to the stinkhorn.
Stinkhorns are pornographic mushrooms. They form large underground webs of threads, which feed on dead and dying plant matter. At scattered points in the stinkhorn network, white rubbery spheres grow. Inside each of them is a pre-formed stinkhorn, which can then spring forth.
As the autumn leaves turn handsomely, I’ve been wondering, why do trees bother? It’s a question scientists have been asking for the past few years, and for the first time, they’ve carried out an experiment to find out.
The color of an autumn leaf can actually take a lot of work. In the fall, the green chlorophyll in a tree fades away, while the tree actively builds new pigments to turn it red or yellow. It’s generally agreed that these colors must serve some function for trees. Otherwise, natural selection would favor drab trees that dropped their leaves without such bother. They could use the energy they didn’t waste on autumn colors to fight diseases, capture more sunlight, or some other essential task.
Galileo discovered Saturn’s rings, but called them ears. If only he could see what Cassini sees.
Cue kettledrums…
Originally published October 13, 2006. Copyright 2006 Carl Zimmer.