Kim, I guess, there isn't really a contradiction. I would say the problem is that they might be so badly adapted that small changes won't help. But that is more of a problem of the rate of change and not an indication that the processes are not at work. They might just lead to extinction because the population can't change fast enough. That'll be selcetion, too for my amature understanding. An analogy from maths (where I come from): in global optimization, if you are on a wide flat plane and you have no clue in which direction to go to find the valley, you are stuck with the solution you have at hand. It might be a rather bad one (extinction) but anywhere you turn it doesn't get (much) better. That doesn't mean that in many cases optimization algorithms won't work they do even in quite bad conditions if you have a lot of time to search. So I think it just comes down to the degree of maladaptation versus the likely rate of change. Cheers, Joerg At 09:36 PM 7/8/2006, Kim van der Linde wrote: >Hi all, > >I am having an interesing discussion at the moment about Natural >selection. The context is a single population of individuals that, due >to changes in the environment, are now maladapted and the population is >reducing in size. Based on the often used definition of differential >reproduction, when there is not much to differentiate with, there is no >longer differential selection, and as such, no natural selection. >However, they are maladapted, so unfit to survive. Any opinions about >this nice contradiction? > >Cheers, > >Kim > >-- >http://www.kimvdlinde.com
-- Jörg Kaduk jk61 at le.ac.uk Lecturer Department of Geography University of Leicester University Road Leicester LE1 7RH United Kingdom
