http://bactra.org/notebooks Cosma's Notebooks en http://bactra.org/notebooks/1994/10/03#directed-evolution Take a large number --- ``billions and billions,'' in the words of Uncle Carl --- of slightly different compounds. Have them perform some chemical task, e.g., catalysis of a reaction. Skim off the ones which do it best and make noisy copies of them. (The first experiments used RNA and the polymerase chain reaction for this ``amplification'' stage.) Repeat, generation after generation. <P>How is it being used? Could it become a ``runaway technology of the recent future''? Connections to <a href="evol-comp.html"> evolutionary computation</a> and <a href="alife.html">artificial life</a>. Could it be used as a scaffolding towards <a href="nanotech.html">nanotechnology?</a> <P>See Gerald Joyce, ``Directed Molecular Evolution,'' <cite>Scientific American</cite> Dec. 1992. According to a <cite>Discover</cite> article, Joyce was inspired by Pynchon's <cite>Gravity's Rainbow</cite>: which goes to show that no work of human hands is completely worthless. <P>This notebook needs lots of work. <ul>To read: <li>Bennett Levitan, ``Models and Search Strategies for Applied Molecular Evolution,'' SFI Working Paper 97-01-003 </ul>