Michael, Remember that natural selection does not immediately either fix or eliminate every new mutation. Instead, many new alleles are able to persist and spread in a population, even if they are neutral or slightly deleterious. These new variants can accumulate over time (until they reach an equilibrium where existing variants drift out of existence as rapidly as new variants arise), which means you don't need a population of billions to have substantial genetic variation. Thus, if selection suddenly starts favoring a different phenotype than it did before, the population doesn't have to wait for new mutations to arise before it can exhibit an evolutionary response. Selection just acts on the pre-existing variation, and the response can therefore be rapid.
This isn't "hiding behind plenty of time and huge numbers." In fact, populations with little genetic variation, whether because they are small or because they are young, are not expected to be very evolutionarily flexible. Time and numbers are essential to understanding why evolution can be so rapid; they aren't something we hide behind. On Wed, Feb 18, 2009 at 4:58 PM, Michael Harvey <[email protected]> wrote: > The people who replied to my post missed the point. Going on about the > mechanics of clocks, typing monkeys, and selection of phenotypes illustrates > why the creationists can ridicule and challenge public debates so easily. > > Hiding behind plenty of time and huge numbers doesn't help the cause. There > aren't billions of cats out there, testing untold useless random gene > mutations in hopes of finding one that will give sharper claws. There aren't > billions of finches on some island, trying out huge numbers of gene > mutations, five eggs at a time, waiting for a random one that gives a > slightly longer beak. > > You must show a biochemical process by which environmental cues direct gene > mutation and expression. It can happen fast in nature, and it happens far > too efficiently to be random. Lamark awaits your research. > > -- > Michael Harvey > Victoria, BC > -- James Crants, PhD Scientist, University of Minnesota Agronomy and Plant Genetics Cell: (734) 474-7478
