If you want to hear about brain science at its birth and today, check out the public radio show Tech Nation, this week. In the first half of the show, I’ll be talking about Soul Made Flesh. In the second half, Steven Johnson will be talking about his excellent new book, Mind Wide Open. You can find out where and when you can listen to the show at the program’s web site, or listen to it on their site archive.
In my last post, I wrote about how our genes work in networks, much like circuits made of elements wired together in various ways. As genes are accidentally duplicated, mutated, and rewired, old networks can give rise to new ones. It’s pretty clear our ancestors could have never become particularly complex if not for this sort of network evolution. As they acquired nerves, muscles, and other tissues, animals needed to organize more and more genes into new circuits. But in saying this I don’t mean to imply that single-celled microbes, such as bacteria, live without gene networks. Far from it. In fact, in many ways bacteria are more adept at network engineering than we are.
As biologists figure out more about how life is, they can then figure out how it got to be that way. First there were genes. Mendel noticed that somehow the wrinkles on wrinkled peas could be transmitted down through the generations, even if some of those generations had no wrinkles at all. It turned out that the wrinkles were the result of a gene; a different version of the gene produced smooth peas. For much of the twentieth century, evolutionary biologists worked out how changes in genes produced evolutionary change. A mutation that alters one position in a gene (or chops out a whole chunk of it) can alter the protein it encodes. As the proteins on a virus mutate, for example, their shape becomes harder for an immune cell to recognize.
The Sunday Telegraph Magazine, February 28, 2004
Janet Dilbeck clearly remembers the moment the music started. Two years ago she was lying in bed on the California ranch where she and her husband were caretakers. A mild earthquake woke her up. To Californians, a mild earthquake is about as unusual as a hailstorm, so Dilbeck tried to go back to sleep once it ended. But just then she heard a melody playing on an organ, “very loud, but not deafening,” as she recalls. Dilbeck recognized the tune, a sad old song called When You and I Were Young, Maggie.
Apologies for the long radio silence. Travelling and the obligatory pre-travelling frenzy shut down the blogging assembly line for a couple weeks. Having wrapped up my west-coast jaunt (thanks to the great crowd that came out for the CSPAN taping at Stanford), I can write a bit about some of the new science that has caught my eye.