"The laws of physics and the rules of math don't cease to apply. That leads me
to believe that evolution doesn't stop. That further leads me to believe that
nature —bloody in tooth and claw, as some have termed it —will simply be taken
to the next level... "[Getting rid of Darwinian evolution is] like trying to get
rid of gravitation. So long as there are limited resources and multiple
competing actors capable of passing on characteristics, you have selection
pressure." —Perry Metzger, predicting that the reign of natural selection would
continue into the indefinite future.
In evolutionary biology, as in many other fields, it is important to think
quantitatively rather than qualitatively. Does a beneficial mutation "sometimes
spread, but not always"? Well, a psychic power would be a beneficial mutation,
so you'd expect it to spread, right? Yet this is qualitative reasoning, not
quantitative—if X is true, then Y is true; if psychic powers are beneficial,
they may spread. In Evolutions Are Stupid, I described the equations for a
beneficial mutation's probability of fixation, roughly twice the fitness
advantage (6% for a 3% advantage). Only this kind of numerical thinking is
likely to make us realize that mutations which are only rarely useful are
extremely unlikely to spread, and that it is practically impossible for complex
adaptations to arise without constant use. If psychic powers really existed, we
should expect to see everyone using them all the time—not just because they
would be so amazingly useful, but because otherwise they couldn't have evolved
in the first place.
"So long as there are limited resources and multiple competing actors capable of
passing on characteristics, you have selection pressure." This is qualitative
reasoning. How much selection pressure?
While there are several candidates for the most important equation in
evolutionary biology, I would pick Price's Equation, which in its simplest
formulation reads:
Δz=cov(vi,zi)
change in averag
ayu-mushi
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