Darwin said the sight of a peacock's tail made him sick.

If, as he had theorized, nature's present forms were the result of generations of lethal whittling,

generations of less survivable forms dying out, leaving the most survivable forms to propagate,

then why would an animal's present form retain a flamboyantly

impractical trait? Having an enormous, partially iridescent, blue and green wedding train

permanently attached to your body just doesn't seem to be the sort of thing that would help

you survive. If anything would hurt you, right, by wasting energy on its development and maintenance,

by interfering with flight, by acting as simultaneously a bug light and a grab handle for predators,

it seems to be the exact sort of thing, natural, simultaneously a bug light and a grab handle for predators.

It seems to be the exact sort of thing, natural selection would select out.

This is what made Darwin nauseous.

This was a stuck out tongue at his theory of natural selection.

How could a tail like that evolve?

Well, it wasn't so clear then, but today everyone seems to more or less agree that the reason the peacock's tail evolved is because peahens like it.

Of course, there's a further debate to be had as to why peahens like it, and some of this is worth being familiar with, theoretically.

Maybe the tails themselves are actually an honest sign of fitness, right? Maybe it shows off the

capacity to acquire excess nutrients

and or resist pathogens and disease

and or survive despite the burden of such an ornament.

It's a pretty impressive thing to grow.

You'd have to be pretty healthy and capable to grow it.

So for the same reason, a Lamborghini is an honest signal of excess wealth,

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