Friday, May 06, 2005

Selection engine

Coughing woke me up. Hence the hour of this post. When I sit or stand, the coughing stops. I think the deeply-retrieved sputum was ... brown? The mere hawking sputum is clear. The nurse said yesterday that my lungs were "perfect," but she thought it was viral. I sure don't feel sick.

Lots to disagree on, but at least Blair speaks in complete sentences, isn't faking a Texas accent, and appears to have been awake in college.

I've been toying with this idea for years, but have yet to do anything about it. I'd normally put it in the Some Day category, but since I am rumored to have limited "some days," I'll toss it out to see if y'all have heard of anything like this.

Picture microorganisms in a fluid. Amoeba, paramecia, bacteria, whatever. The fluid circulates with the assistance of a pump. Through a very fine filter. All the big organisms that don't pass through the filter are killed. Or maybe the small ones are. Whatever. The mechanism does this at regular intervals and exerts a selective pressure on size. The size of the mesh holes are progressively altered. It would be interesting to see at what point the constraints on size (both large and small) hit. I think this would tell us more about the limits of biochemistry than about genetic potential. At what point is a cell too big for necessary reactions to take place? All Steve McQueen references aside, what is the largest cell found in nature? (Apparently it is an Ostrich egg). Can we make an amoeba larger than that? When does a cell become too small to function?

You can set up a similar rig to select for speed. The mechanism regularly exposes one end of the fluid to something unpleasant (like heat), and those amoeba or paramecia that move away from the heat fastest, live to breed while the others die. It's easiest to do this with aquatic microorganisms, but the same could be done with fruit flies.

Yes, I know it's cruel, but how cruel can you be to bacteria or plankton or amoeba? Has anyone done this?

Left grip is 41 pounds (39, 41, 39), right grip is 95 pounds (95, 95, 88), left leg balance is 10.1 seconds, and inhale volume is 4800 mL.

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