The Nice Rats
OK, here's my plan: genetically engineered, super-tame, super-skinny, super-long-lived, nonbreeding rats. Or humans. Science says we can do it!
I have this problem where I read two or three articles about so-called recent discoveries and start mixing and matching them, trying to piece together the ultimate ÃƒÂ¼berexperiment that will end the world. I've been dreaming about super-rodents for the past two days, and it's all the fault of Nicholas Wade and Alison Motluck, two journalists who've published stories about tame rats and nonpubescent mice respectively.
I love it when scientists do experiments on animals and report said experiments in various footnote-heavy journals, and then journalists get their hands on them and ask, "But couldn't this be done to humans too?" Most decent scientists are willing to admit that of course anything is possible until proved otherwise. So if that question is asked in the right way, your average scientist will get talked into a quote about how drugs that do weird things to mice could do them to humans too.
Which brings me back to my exciting recent plan about rats. Wade, writing in the New York Times science section, describes an interesting long-term experiment that involved breeding tame animals in the Soviet Union. When Dmitri K. Belyaev started the experiment in 1959, he divided a posse of sewer rats into two groups and bred one for "tameness" and the other for ferocity. Over several generations, he was able to generate an extremely friendly group of rats and an extremely pissed-off one. Belyaev died several years ago, but recently some researchers at the Max Planck Institute in Germany got their hands on rats directly descended from the two populations, and they'll be running genetic tests on them to figure out which genes are associated with "niceness" and "nastiness" in rats.
Inevitably, Wade raises the question of what this has to do with humans. Is it possible that humans could be domesticated, or that we have already domesticated ourselves? He quotes some expert saying -- not surprisingly -- that it's possible. And now his readers are left with a bizarre and irrelevant idea as they finish what is otherwise a completely respectable and cool piece of science journalism. Instead of considering Belyaev's experiment as something that charted how one species breeds another to become its ally, readers will be thinking: can humans be tamed? The answer should be: that's outside the scope of this experiment. But that doesn't stop our intrepid Wade from bringing it up gratuitously, as if somehow applying this research to humans makes it more interesting. (My fantasy is that some clueless editor tortured Wade by asking over and over, "But how is this relevant? What's the human angle?" until the poor guy tacked on that dreadful ending.)
Sometimes, however, Homo sapiens actually is relevant. For instance, Motluck reports in New Scientist that two teams of scientists have worked out which gene is responsible for kicking off puberty in mice. The gene, gpr54, exists in humans too, and it functions in virtually the same way. Drugs that tinker with the onset of puberty in mice should, therefore, do the same for humans. Why is this fascinating? Not just because of the "human angle" of helping late bloomers start filling out their jockstraps more quickly, but also because it means that gpr54 was preserved over the entire course of evolution since mouse and human ancestors split off from each other. In other words: that's a hell of an old gene. And as a side note, it turns out that gpr54 may also interact with genes that measure levels of fat in the body. This fits with anecdotal observations that extremely undernourished or highly athletic women often start menstruating later.
So now you understand my fantasy about the super-tame, skinny, nonpubescent rats. First we'll breed 'em tame (or just steal some already-tamed ones from the Max Planck graduate students). Then we'll give them a drug that blocks gpr54 receptors so they don't go through puberty, which may have the additional side effect of keeping them thinner. Or we could just starve them, which would also prevent puberty and make them live longer -- there are about a zillion studies showing that people who starve themselves wind up living about 5 to 10 years longer than average.
Now I feel like I'm writing the jacket copy for a new nutritional self-help book. Which brings me to my final question, which (of course) is about humans: what does my concocted experiment say about the things humans study?