You are obviously just wrong. Every species in existence is under
multiple selection pressures every day. Just look at the difference
between night and day. You have to have some weird boneheaded denial of
reality to not understand that. Just take the example of the guppies
(there were several). These fish have to extract oxygen from the water,
they have to balance their water intake and waste. They have to eat.
They have to reproduce. They have to avoid predators (multiple
different types, just think even water beetles prey on them). In spite
of all of this what happens? This doesn't even take into account
seasonal differences.
You obviously don't know what you are talking about.
> .
> Selection of a black moth in a dark environment or a white moth in a light environment is simply selection for alleles already existing in the population.
What a bonehead. When the lichen died off and the branches were covered
with coal dust and ash the environment obviously changed. Dark moths
were selected for under those conditions, but what else was going on.
The moths still had to survive the winters. They still had to suffer
day and night changes, hot and cold. Their offspring had to find
something to eat etc. etc. These populations were obviously under
multiple selection pressures every day. What do you think living is?
You are confusing studies that link certain environmental conditions to
certain changes as general examples of natural selection. These are
just examples where we have some type of idea of what the particular
selection pressure was for that particular trait. If you knew anything
you would know that natural selection is also acting on multiple other
traits at the same time. It is called biology learn something about it.
Look at your own example of bacterial antibiotic resistance.
Antibiotics are not the only selective pressure on those bacteria. They
have to reproduce and find food. They have to withstand multiple
environmental shifts through their life cycles. Natural selection on
all the other traits does not stop just because you put antibiotics into
the environment. This is obviously a case where you just do not know
what you are talking about.
Ron Okimoto