On 22/09/2008, at 12:37 AM, Nick Arnett wrote: > On Sat, Sep 20, 2008 at 10:16 PM, Doug Pensinger <[EMAIL PROTECTED]> > wrote: >> >> Is there no way to define success in evolutionary terms? Wiki >> describes >> natural selection thus: Over many generations, adaptations occur >> through a >> combination of successive, small, random changes in traits, and >> natural >> selection of those variants best-suited for their environment" Is >> the use >> of best in that description a mere tautology? Or if I had said >> best-suited >> would it have changed the meaning of my statement appreciably? > > > There is at least one problem with "best" that strikes me > immediately -- the > "environment" is not static. Every living thing co-evolves. So > what is > "best" at one point is not best in another. The living environment is > shaped by and shapes life.
You've hit on something that's both profound and irrelevant. Species, and fitness, are both snapshots in time. There are various analogies that are used to picture the wider possibilities over time and space - adaptive landscape is one, morph space is another. But really, species is a description of a population at a particular period in time, and fitness is a relative measure of success at a particular period in time. Biologists take all this as a given - the fuzziness and the continuous nature of biology is just the way it is, and understanding this and seeing nature as a snapshot, looking at broader timescales while observing a moment, is something that once learned changes one's perspective. (It's not how it's always been, as biology started as pigeon-holing). Geologists and cosmologists see things similarly. Good post. Charlie. _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
