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(Stories from the Sea: How Life Came to Land)
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Life for my kind wasn't always this way.
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There was a time when no animals lived on land.
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All life was in the ocean.
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The ocean's where all of us animals got our start,
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more than half a billion years ago,
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This is where all animal body types -- or phyla, as scientists call them -- first evolved.
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You know, there are more than 30 animal phyla,
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but only a handful of major ones had what it took to do something completely daring:
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step out of the ocean, and on to dry land.
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So, which of these land-dwelling phyla first invaded the land?
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Was it me and my mollusc friends, with our amazing mantles and single foot?
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Perhaps the chordate crowd, with their notochords, segmented muscles and big bony skeletons.
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Or maybe those lowly annelid worms, with their powerful ringed bodies.
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Or did the Arthropods first make landfall, with their little flexible suits of armor -- their exoskeleton?
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Ah, yes. The arthropods.
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From crustaceans to millipedes, spiders to insects,
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the arthropods outnumber all animals on land.
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So what's their secret?
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Their exoskeleton is key, but here's the real kicker: jointed appendages.
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They're like little living Swiss army knives:
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antennae, multiple mouth parts, an obscene number of legs, if you ask me.
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There's one group of arthropods -- the insects --
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that really rule the land.
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Three body parts, six legs, and an annoying tendency to take over.
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Sure, they have to molt to grow, but that doesn't seem to pose a problem.
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The insects even invented the first wings, and conquered the skies.
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Ah, well. So what if arthropods were the first to reach land
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and invent flight, a hundred million years before the rest of us?
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So what if they pollinate crops around the world,
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and make up 75% of all land animal species?
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And that for every single human, there's 200 million of them?
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Sure, those leggy arthropods may still be in the lead when it comes to conquering land,
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but we still rule in the sea.
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There are more species of molluscs in the ocean than any other animal phylum.
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We're just getting started up here on land.
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Besides, the seas are rising. Just give us some time.
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Who knows who'll end up ruling this ocean planet?