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The dead coming back to life sounds scary.
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But for scientists, it can be
a wonderful opportunity.
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Of course, we're not talking about zombies.
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Rather, this particular opportunity
came in the unlikely form
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of large, slow-moving fish
called the coelacanth.
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This oddity dates back 360 million years,
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and was believed to have died out
during the same mass extinction event
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that wiped out the dinosaurs
65 million years ago.
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To biologists and paleontologists,
this creature was a very old and fascinating
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but entirely extinct fish,
forever fossilized.
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That is, until 1938 when Marjorie Courtenay-Latimer,
a curator at a South African museum,
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came across a prehistoric looking, gleaming
blue fish hauled up at the nearby docks.
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She had a hunch that this strange,
1.5 meter long specimen was important
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but couldn't preserve it in time
to be studied and had it taxidermied.
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When she finally was able to
reach J.L.B. Smith, a local fish expert,
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he was able to confirm, at first site,
that the creature was indeed a coelacanth.
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But it was another 14 years before
a live specimen was found in the Comoros Islands,
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allowing scientists to
closely study a creature
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that had barely evolved
in 300 million years.
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A living fossil.
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Decades later, a second species
was found near Indonesia.
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The survival of creatures
thought extinct for so long
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proved to be one of the
biggest discoveries of the century.
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But the fact that the coelacanth
came back from the dead
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isn't all that makes
this fish so astounding.
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Even more intriguing is the fact that
genetically and morphologically,
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the coelacanth has more in common
with four-limbed vertebrates
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than almost any other fish,
and its smaller genome is ideal for study.
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This makes the coelacanth a powerful link
between aquatic and land vertebrates,
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a living record of their transition from
water to land millions of years ago.
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The secret to this transition is in the fins.
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While the majority of ocean fish
fall into the category of ray-finned fishes,
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coelacanths are part of a much smaller,
evolutionarily distinct group with thicker fins
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known as lobe-finned fish.
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Six of the coelacanth's fins contain bones
organized much like our limbs,
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with one bone connecting
the fin to the body,
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another two connecting the bone
to the tip of the fin,
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and several small,
finger-like bones at the tip.
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Not only are those fins structured
in pairs to move in a synchronized way,
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the coelacanth even shares
the same genetic sequence
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that promotes limb development
in land vertebrates.
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So although the coelacanth
itself isn't a land-walker,
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its fins do resemble those
of its close relatives
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who first hauled their bodies onto land
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with the help of these
sturdy, flexible appendages,
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acting as an evolutionary bridge
to the land lovers that followed.
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So that's how this prehistoric fish
helps explain the evolutionary movement
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of vertebrates from water to land.
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Over millions of years,
that transition
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led to the spread of all
four-limbed animals, called tetrapods,
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like amphibians, birds, and even
the mammals that are our ancestors.
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There's even another powerful clue
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in that unlike most fish,
coelacanths don't lay eggs,
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instead giving birth to live, young pups,
just like mammals.
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And this prehistoric fish will continue to
provide us with fascinating information
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about the migration of vertebrates
out of the ocean over 300 million years ago.
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A journey that ultimately drove
our own evolution, survival and existence.
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Today the coelacanth remains the symbol
of the wondrous mysteries that remain
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to be uncovered by science.
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With so much left to learn about this fish,
the ocean depths and evolution itself,
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who knows what other well-kept secrets
our future discoveries may bring to life!