Posts Tagged Bacteria
One well-known metaphor for the process of biological evolution is ‘tinkering.’ First proposed by François Jacob in 1977 in a now-famous paper in the journal Science, the idea captures two facets of evolution: the fact that new things must be developed from pre-existing things, and the apparent fact that evolution does not proceed with guidance. The picture is one of an actor mindlessly fiddling with implements, tossing them into the mix to see what happens. A believer might prefer the actor to be mindful, perhaps even goal-driven, but the process shows no evidence of this—Hume’s “stupid mechanic” seems a more apt metaphor to me. But mystical preferences aside, a view of evolution as tinkering brings a set of expectations or predictions to evolutionary thought.
One of those predictions is that innovations in evolution should be rare. More precisely, whenever something “new” appears, we expect it to be built from old stuff, from the components already there. No matter how innovative the new thing looks, we expect it to be a subtle reworking of whatever came before. Read the rest of this entry »