Re: Minimization principal for evolution

But wait, you still have to explain why some mountain tops don't have
clouds, and it's only when two mountain tops join, allowing a cloud to
spill from one to the other. That's not natural. Clouds form
spontaneously from ambient humidity. They don't breed from one to
another. Your cloud at mountain top metaphor would seem to apply better
to abiogenesis than evolution. So upside-down function, puddle of water
in valleys, still wins over hill-climbing/cloud metaphor.
You need to think of a cloud of gnats rather than a cloud of
water droplets that might form by spontaneous generation.

Phewwwwffff! (Bronx cheer!)

I'm not sure why Wright chose to describe 'fitness landscapes'
upside-down from the physicist's convention. Probably because
the usual metaphor of evolution has species arising in the slime
and progressing uphill.

Ugh! (Not the native-American sign of greeting. Rather some disgust.)

But there is also a ghost of the old idea that life is somehow
anti-entropic. You fall downhill if you are an inanimate entropy
maximizer. But you climb uphill if you are a living organism thumbing
your nose at the second law of thermodynamics.

Double, nay *triple*, ugh!

But ignoring all those really stupid reasons for turning the
energy-well model upside down, you've accidently convinced me:
There some self-regulated arms-race games, of which the most popular is
Poker. Beginners play an easy game. If one of the players is strong, he
pushes the game to be more difficult, thereby increasing his advantage
over the his novice opponent(s). In Poker, he does it by bidding more.
In Chess, he does it by making a bunch of pawn sacrifices to open up
the position. In Go, he does it by making an invasion and thereby
starting a large fight. You get the idea?

In arms races in evolution there's something like that. Each of the two
parties makes it more difficult for the other party. In the metaphor,
anything that drowns is out of the picture. The short-term goal is to
stay above the rising water level. A basic fact of arms-races
(preditor/prey, or diseaseParasite/host, or male/female, those are the
only three considered here) is that whenever one species climbs up its
hill, that causes the water level for its opponent to rise. (It works
the same both ways, whichever is the climber, the other finds water
rising at it.) If the water level is high, most of your individuals at
low levels drown, so there's strong selection for only the very
highest. If the water level is low, there's not much selection, so you
mostly sit fast. So it's only when your opponent makes some success,
that your own water level rises, and you are forced to evolve up-hill
yourself. Another basic fact is that each of the two parties *needs*
the other, and if either decreases too much in number it causes a
supply/demand imbalance which automatically favors reproduction of the
small-number party and disfavors reproduction of the large-number
party. (In effect it's almost like that Devil's game from Sci-Fi where
you are not allowed to die, any time you get killed you are
reincarnated to suffer it all over again.) So if your opponent makes a
big advance and thereby raises your water level a lot, you suffer
massive death of all your low-level individuals as the water overtakes
them, but at the same time supply/demand gives you massive fecundity of
those few who are at high levels, so you really do evolves quickly in
response, rather than go extinct.

Maybe we should liken this to a double see-saw: There's a tank of water
under each person's seat, and each person's seat is at the same level
as the *other* person's tank of water. So if you rise to get out of the
water, you are also dunking your opponent, who rises to get away,
causing you to be dunked. I don't know if that metaphor helps any.

Anyway, imagine two fitness landscapes where the population level on
either landscape controls the water level on the *other* landscape,
plus the supply/demand rule for reproduction rates.
..

.

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