Switching Genes On and Off

Extras

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  Pompeii's Secret Underworld Preview

  Archaeologists uncover new truths about Pompeii, a wealthy Roman playground with dark secrets.

  0:30
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  How Birds Survived the Dinosaur Apocalypse

  Birds are today’s only living dinosaurs, but how did they survive the asteroid?

  2:48
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  Egypt's Tombs of Amun Preview

  A long lost ancient cemetery opens the door to a unique period in Egyptian history.

  0:30
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  What You’re Probably Seeing If You Spot a UFO

  Our skies are full of objects, natural and manmade, that are not as strange as you might think.

  2:17
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  What Happens to Your Checked Bag at the Airport?

  Getting the right bag to the right plane requires an ingenious system. Here’s how it works.

  2:34
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  Area 51: UFO Sightings and an Infamous Government Cover-Up

  Area 51’s UFO myths became a cover for secret testing of cutting-edge military technology.

  2:35
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  Is the Government Hiding Information on UFOs?

  What does the government know about UFOs? Experts weigh in on the need to identify these objects.

  1:03
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  The Physics of Breaking, a New Olympic Sport

  Here are three moves in breaking, the newest Olympic sport, that appear to defy the laws of physics.

  1:19
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  Who is the Mystery Man Buried Under Notre Dame?

  Can scientists identify the man buried inside a mysterious coffin found under Notre Dame?

  3:00
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  Dino Birds Preview

  Fossils reveal how birds survived the killer asteroid and became today’s only living dinosaurs.

  0:29