Expert: Walter Hintz - 2/28/2007

Question
im sorry i couldnt get back to you.  whenever i clicked the link to ask a followup i got a message that you were "maxed out" i tried to rephrase the question to make it clearer (i hope)
has evolution ceased? (just rhetorically asked)
what i dont get: in order for the process of natural selection to occur in a meaningful way leading to the myriad of details that make a species successful, there MUST be a very wide range of very commonly occuring variations that occur in a species. in other words a bumblebee today benefits somehow by being yellow.  let's say the environment changes, giving purple a survival advantage.  well i dont think that occurs.  i dont think anyone ever saw a purple, or orange, or green bumblebee. it seems there is very very little variation within species. for example, look at a maple tree.  it will have tens of thousands of leaves, all unique, but all maple leaves.  you will never see an elm or oak leaf on a maple tree.  you can examine maple trees and billion of maple leaves all your life and not see an elm leaf on one.
where is the variation that would make the raw material for natural selection to operate?
there MUST have been a whole different world of variation out there earlier.  where has it gone?  what if the environment changed making it better for a person to have molars in front and incisors in the back.  how would this occur.  i dont believe any dentist anywhere ever saw a person with such an arrangement.  the species today seem far too stable.
i dont get it

to summarize:
there are billions and billions of inheritable characteristics that make up the variety of species today.  to get from the first organism to today, these many billions of features must have spontaneously appeared (as mutations or whatever). and actually there must have been MANY billions (or trillions) more that were NOT advantageous and therefore not selected.  but they must have been there.
so every species in those days must have had a huge degree of variation both in number and in degree of variance.
we just dont see anything like that today.  the variation today is really extremely limited in degree and number (i.e differences in leaf design), compared to what should be present to allow evolution to occur.
variation is the raw material of evolution but it is very sparse.  it must have been vastly more fluid in the past.what happened?
thanks

Answer
Glad you got back to me feiv;
I get a lot of questions and allexperts poses some limits so if it happens again just try later.
 I have been trying to get into your head here. Perhaps you are correct and perhaps evolution has in a sense "slowed down". Maybe the emergence of new species and the extinction of older species is in balance.  The evolution of many species is presently in stasis.  There are many specie of insects that we have not even discovered yet.  Most insects,like the ants, have not changed in millions of years.  The DNA of a leaf cutter ant is likely to be exactly the same that it was during the Jurassic period.
 As I stated previously I have done an about face on speciation and I do not believe that variation is the raw material of evolution.  If random mutations causing variation brought about new species ants would be evolving.
Evolution is a slow process and life has been around for a long time and I suspect you are right in assuming in the past a lot more was going on; more evolving species and more extinction.  Living things are subject to Natural Laws especially the laws of physics and chemistry.  Human activity is speeding up the extinction rate by introducing environmental changes.
 I probably not answered your question but all I can do is concur with you somewhat.
AS to speciation please get a copy of Acquiring Genomes by Lynn Margulis.