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  • Out here in California's serene central valley, there's a game underway.

  • 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.

  • OrangeThese guys are the brutes, the meatheads.

  • Bigger, stronger.

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

  • YellowThese 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.

  • You'll be the first to know when new episodes are up.

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

  • We read every single one.

  • Thanks, and see you next time!

Out here in California's serene central valley, there's a game underway.

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B1 US paper scissors rock paper scissors orange lizard monogamous

These Lizards Have Been Playing Rock-Paper-Scissors for 15 Million Years | Deep Look

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    Binyann posted on 2020/10/13
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