One animal is locked in a perpetual, unwinnable cycle of rock paper scissors.

A three-way competition that's been raging for millennia.

Meet the side-blotched lizard, named for that patch of dark color on its side.

These lizards are all one species, but they have three different colors.

You see it on their throats.

Some are more orange.

Others more blue, or yellow.

Each male lizard has a different trick for getting a mate that corresponds to their color.

Orange—These guys are the brutes, the meatheads.

Bigger, stronger.

They set up territories with lots of females and defend them aggressively.

Yellow—These guys are sneaky.

They don't try to hold territories.

Instead, they hide and then dart in, as often as they can, for a chance to mate with an unguarded female.

Blues have a whole other strategy.

They're monogamous.

They put all their focus on just one female.

Researchers at UC Santa Cruz figured out the game.

So here's how it plays out, the rock paper scissors part:

Orange beats blue.

They're bigger and more aggressive.

Yellow beats orange, because oranges can't keep track of all those females.

It's easy for yellows to sneak by them.

Blue beats yellows, because blues are vigilant; yellows can't fool them.

And while we're on these Blues...

Because they're monogamous, they aren't competitive with other blues.

They cooperate with each other, make friends, even warn their blue neighbors when intruders are nearby.

See those little push-ups?

In fact, they've been known to risk their own lives for other blues.

It's called altruism.

Even Darwin didn't imagine this could happen.

Anyway...

You might think that over time, one color would prevail.

Like, those altruistic Blues would win.

The whole species would gradually become blue.

But with these guys, it doesn't happen.

Each color is kept in check by one of the other colors.

And if one of the colors starts to fall behind, the females bring it back in line.

Because they tend to prefer whatever color male is most rare that season.

So, if blues are getting the upper hand, females go for yellows or oranges.

If the females were to have a change of heart and stop going for the underdog, well, then, one color might win out, another might disappear entirely.

In other words, the species would evolve, change.

But for the last 15 million years, that hasn't happened.

It's an ancient game of roshambo, with no end in sight.

Hey! While you admire this other resident of California's central valley, consider subscribing to Deep Look.

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And if you're feeling altruistic, share your thoughts in the comments section.

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Thanks, and see you next time!