Re: Evolution in a microcosm

[Zack Wilson <aquamaniac@earthlink.net>]

Thank you Scott. You're the only one who has actually suggested some real
instances of evolution.

To address your first example, prettier fish being favored or discriminated
against. This is the instance in which evolution can and does occur, so to
speak. Microevolution (the changing or development within a species) does
occur and can be observed. I find this aspect to be particularly pertinent
with regards to Apistos (see, I can tie it in with our main topic!), where
every little difference in each new fish found is interpreted as evidence of
a new species. Environmental pressure can and does lead to changes within a
species to adapt to these pressures. However, these changes occur WITHIN the
species and do not lead to it becoming a different species (unless you want
to change the definition of species, which many are trying to do). A given
species can only change to the degree that its pre-existing genetic
variation allows it to. New genes allowing adaptation do not occur, or at
least have never been identified. When mutations (actual infusions of new
genetic material) do occur, they have been deleterious to the overall health
of the species in all observed instances.

Regarding your second example using the Ambystoma species. I can do you one
better. There are many different group of people in the world with many
distinctions from one another. Intermarriages have produced many new
"hybrids". Strangely all of these "hybrids" have been fertile and viable so
far. Now we have many new species of humans running about. Oh, wait, I guess
they were always one species, my bad.

Well, now that I've gotten that out of my system, I'm going back to my water
changes.

Zack



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