Re: Origin of stimulus reception


*** wrote:
How would the single cell membrane protein "know" how to respond? I
can understand the protein could be the result of a mutation, but what
would be the selecting test? Then how would a beneficial response be
formed in a way that would alter the DNA?

It doesn't actually know how to respond. What happens is that each
step of the stimulus-response pathway is laid down by random mutation
followed by natural selection. Those mutations which happen to improve
the pathway outcompete both the original form and those which have
suffered harmful mutations.

This is _very_ wasteful. On the other hands, micro-organisms breed
_very_ rapidly, so Nature can afford a lot of waste here.

There _may_ be more sophisticated mechanisms within cells which
self-organize in a way that somewhat cuts down on the waste -- I've
read hypotheses to the effect. There are still a lot of things about
the internal functioning of cells that we don't much understand. Heck,
we only discovered cytoskeletons within the last half-century.

Sincerely Yours,
Jordan

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