GreyThumb.blog offers an interesting analogue between research on animal breeding and the fall of Enron.  Before 1995, the way animal breeding worked was that you would take the top individual performers in each generation and breed from them, or their parents.  A cockerel doesn't lay eggs, so you have to observe daughter hens to determine which cockerels to breed.  Sounds logical, right?  If you take the hens who lay the most eggs in each generation, and breed from them, you should get hens who lay more and more eggs.

Behold the awesome power of making evolution work for you!  The power that made butterflies - now constrained to your own purposes!  And it worked, too.  Per-cow milk output in the US doubled between 1905 and 1965, and has doubled again since then.

Yet conjuring Azathoth oft has unintended consequences, as some researchers realized in the 1990s.  In the real world, sometimes you have more than animal per farm.  You see the problem, right?  If you don't, you should probably think twice before trying to conjure an evolution to serve you - magic is not for the unparanoid.

        "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?

Followup to:  Evolutions Are Stupid

It is a very common misconception that an evolution works for the good of its species.  Can you remember hearing someone talk about two rabbits breeding eight rabbits and thereby "contributing to the survival of their species"?  A modern evolutionary biologist would never say such a thing; they'd sooner breed with a rabbit.

It's yet another case where you've got to simultaneously consider multiple abstract concepts and keep them distinct.  Evolution doesn't operate on particular individuals; individuals keep whatever genes they're born with.  Evolution operates on a reproducing population, a species, over time.  There's a natural tendency to think that if an Evolution Fairy is operating on the species, she must be optimizing for the species.  But what really changes are the gene frequencies, and frequencies don't increase or decrease according to how much the gene helps the species as a whole.  As we shall later see, it's quite possible for a species to evolve to extinction.

Followup to:  An Alien God, Adaptation-Executers not Fitness-Maximizers, Evolutionary Psychology

Before the 20th century, not a single human being had an explicit concept of "inclusive genetic fitness", the sole and absolute obsession of the blind idiot god.  We have no instinctive revulsion of condoms or oral sex.  Our brains, those supreme reproductive organs, don't perform a check for reproductive efficacy before granting us sexual pleasure.

Why not?  Why aren't we consciously obsessed with inclusive genetic fitness?  Why did the Evolution-of-Humans Fairy create brains that would invent condoms?  "It would have been so easy," thinks the human, who can design new complex systems in an afternoon.

Followup to:  Evolutionary Psychology

It takes hundreds of generations for a simple beneficial mutation to promote itself to universality in a gene pool.  Thousands of generations, or even millions, to create complex interdependent machinery.

That's some slow learning there.  Let's say you're building a squirrel, and you want the squirrel to know locations for finding nuts.  Individual nut trees don't last for the thousands of years required for natural selection.  You're going to have to learn using proteins.  You're going to have to build a brain.

Followup to:  An Alien God, Adaptation-Executers not Fitness-Maximizers

Like "IRC chat" or "TCP/IP protocol", the phrase "reproductive organ" is redundant.  All organs are reproductive organs.  Where do a bird's wings come from?  An Evolution-of-Birds Fairy who thinks that flying is really neat?  The bird's wings are there because they contributed to the bird's ancestors' reproduction.  Likewise the bird's heart, lungs, and genitals.  At most we might find it worthwhile to distinguish between directly reproductive organs and indirectly reproductive organs.

This observation holds true also of the brain, the most complex organ system known to biology.  Some brain organs are directly reproductive, like lust; others are indirectly reproductive, like anger.

Where does the human emotion of anger come from?  An Evolution-of-Humans Fairy who thought that anger was a worthwhile feature?  The neural circuitry of anger is a reproductive organ as surely as your liver.  Anger exists in Homo sapiens because angry ancestors had more kids.  There's no other way it could have gotten there.

This historical fact about the origin of anger confuses all too many people.  They say, "Wait, are you saying that when I'm angry, I'm subconsciously trying to have children?  That's not what I'm thinking after someone punches me in the nose."

No.  No.  No.  NO!

"Individual organisms are best thought of as adaptation-executers rather than as fitness-maximizers."
        —John Tooby and Leda Cosmides, The Psychological Foundations of Culture.

Fifty thousand years ago, the taste buds of Homo sapiens directed their bearers to the scarcest, most critical food resources—sugar and fat.  Calories, in a word.  Today, the context of a taste bud's function has changed, but the taste buds themselves have not.  Calories, far from being scarce (in First World countries), are actively harmful.  Micronutrients that were reliably abundant in leaves and nuts are absent from bread, but our taste buds don't complain.  A scoop of ice cream is a superstimulus, containing more sugar, fat, and salt than anything in the ancestral environment.

No human being with the deliberate goal of maximizing their alleles' inclusive genetic fitness, would ever eat a cookie unless they were starving.  But individual organisms are best thought of as adaptation-executers, not fitness-maximizers.

Followup to:  Fake Justification, The Tragedy of Group Selectionism

I've previously dwelt in considerable length upon forms of rationalization whereby our beliefs appear to match the evidence much more strongly than they actually do.  And I'm not overemphasizing the point, either.  If we could beat this fundamental metabias and see what every hypothesis really predicted, we would be able to recover from almost any other error of fact.

The mirror challenge for decision theory is seeing which option a choice criterion really endorses.  If your stated moral principles call for you to provide laptops to everyone, does that really endorse buying a $1 million gem-studded laptop for yourself, or spending the same money on shipping 5000 OLPCs?

We seem to have evolved a knack for arguing that practically any goal implies practically any action.  A phlogiston theorist explaining why magnesium gains weight when burned has nothing on an Inquisitor explaining why God's infinite love for all His children requires burning some of them at the stake.

There's no mystery about this.  Politics was a feature of the ancestral environment.  We are descended from those who argued most persuasively that the good of the tribe meant executing their hated rival Uglak.  (We sure ain't descended from Uglak.) 

Before 1966, it was not unusual to see serious biologists advocating evolutionary hypotheses that we would now regard as magical thinking.  These muddled notions played an important historical role in the development of later evolutionary theory, error calling forth correction; like the folly of English kings provoking into existence the Magna Carta and constitutional democracy.

As an example of romance, Vero Wynne-Edwards, Warder Allee, and J. L. Brereton, among others, believed that predators would voluntarily restrain their breeding to avoid overpopulating their habitat and exhausting the prey population.

But evolution does not open the floodgates to arbitrary purposes.  You cannot explain a rattlesnake's rattle by saying that it exists to benefit other animals who would otherwise be bitten.  No outside Evolution Fairy decides when a gene ought to be promoted; the gene's effect must somehow directly cause the gene to be more prevalent in the next generation.  It's clear why our human sense of aesthetics, witnessing a population crash of foxes who've eaten all the rabbits, cries "Something should've been done!"  But how would a gene complex for restraining reproduction—of all things!—cause itself to become more frequent in the next generation?

Followup to:  Natural Selection's Speed Limit and Complexity Bound

If you've read anything Stephen J. Gould has ever said about evolutionary biology, I have some bad news for you.  In the field of evolutionary biology at large, Gould's reputation is mud.  Not because he was wrong.  Many honest scientists have made honest mistakes.  What Gould did was much worse, involving deliberate misrepresentation of science.

In his 1996 book Full House: The Spread of Excellence from Plato to Darwin, Stephen J. Gould explains how modern evolutionary biology is very naive about evolutionary progress.  Foolish evolutionary biologists, says Gould, believe that evolution has a preferred tendency toward progress and the accumulation of complexity.  But of course - Gould kindly explains - this is simply a statistical illusion, bolstered by the tendency to cite hand-picked sequences like bacteria, fern, dinosaurs, dog, man.  You could equally well explain this apparent progress by supposing that evolution is undergoing a random walk, sometimes losing complexity and sometimes gaining it.  If so, Gould says, there will be a left bound, a minimum at zero complexity, but no right bound, and the most complex organisms will seem to grow more complex over time.  Even though it's really just a random walk with no preference in either direction, the distribution widens and the tail gets longer.

What romantics, ha ha, those silly evolutionary biologists, believing in progress!  It's a good thing we had a statistically sophisticated thinker like Stephen J. Gould to keep their misconceptions from infecting the general public.  Indeed, Stephen J. Gould was a hero - a martyr - because evolutionary biologists don't like it when you challenge their romantic preconceptions, and they persecuted him.  Or so Gould represented himself to the public.

There's just one problem:  It's extremely unlikely that any modern evolutionary theorist, however much a romantic, would believe that evolution was accumulating complexity.