Surprisingly often, scientific researchers make what (eventually, perhaps after decades) turn out to be bad assumptions. They simplify a vexing problem in order to investigate it with the available tools, and then assume that what they’ve learned describes what happens in the real world, forgetting that they began by making a simplifying assumption.
Right now I’m reading Microcosm, a wonderful layman’s science book about the bacterium E. coli. You may not know much about E. coli, but they know quite a lot about you, at least in a vague, utilitarian way, because billions of them are living in your intestines right now.
E. coli has been quite extensively studied in the laboratory. It’s right up there with mice and fruit flies as one of the favorite organisms used in research. But research can’t be done in your intestines. On p. 51, the author (Carl Zimmer) says this:
“Out of the 4,288 genes scientists have identified in E. coli … only 303 appear to be essential for its growth in a laboratory. That does not mean the other 3,985 genes are all useless. Many help E. coli survive in the crowded ecosystem of the human gut, where a thousand species of microbes compete for food.”
But I’m not here today to meditate on intestinal parasites (though that’s a topic worth meditating on). I’m a lot more interested in what happens inside of E. coli. The little critter is a jam-packed protein circus! Large molecules are whizzing around carrying out amazingly intricate Read the rest of this entry »