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20. AIDS Virus Has an Ancient History (pictured): SIV, the virus that spawned HIV, was present in primates for at least 32,000 years.
19. Ocean Ooze Teems With Life: Do bacteria in the ocean floor's muck have a relay system to get the oxygen they need?
18. Helper Gene Makes Cancer Deadly: Researchers idenify a gene they dub "Mahjong" that determine whether cancerous cells get the upper hand.
17. New Hope for the World's Forests: Here's some good news: in the last decade, forest loss has slowed worldwide.
16. Google Whacked by Hack Attack: All signs point to China as the source of a malicious hack.
15. A Universal Vaccine Could Eliminate Flu: By targeting a protein found on the surface of all flu virus strains, an experimental vaccine could take the guesswork out of flu prevention.
14. Super-Material Gets Supersized: If engineers can produce sheets of graphene (made up of a single layer of atoms), what will they do with it?
13. Bats Devastated by Deadly Plague: White-nose fungus is wiping out bat colonies around the United States--and scientists don't know how to stop it.
12. Brain Map Shows You Think Like a Worm: Your cerebral cortex isn't so different from the clump of neurons in a marine ragworm.
11. Interview with Geoff Marcy: The astronomer is leading the hunt for Earth-sized, life-friendly exoplanets.