Early Walt: 5 Most Incredible Discoveries of the Week

Sure, NASA found seven Earth-size planets that could theoretically harbor life, but that wasn't the only discovery to make headlines this week:

• Grad Student Finds Early Walt Whitman Novel: A University of Houston grad student poking around in the Library of Congress' archives stumbled across an 1850s novel by none other than Walt Whitman. The Life and Adventures of Jack Engle didn't do much for Whitman when it came out, but readers might pick up on a voice that would emerge in force a few years later in Leaves of Grass. A tiny newspaper ad led to the discovery.

• Sleeping Late May Be Early Warning of Alzheimer's: Seniors who indulge in a morning lie-in may want to take note. A new study found that older adults who slept more than nine hours a night were at double the risk of developing Alzheimer's and other neurological disorders. They're talking about a symptom, not a cause, and it may be the body's way of trying to fix things.
• Salmonella May Have Doomed the Aztecs: Evolutionary geneticists are floating the possibility that a strain of salmonella is what sickened and killed millions of natives in Mexico in the 1500s, essentially bringing about the collapse of the Aztec empire. Teeth from 29 bodies buried in the Oaxacan highlands of Mexico after an outbreak around 1550 provided the telltale evidence.
• Men Who Exercise Strenulously May Have Lower Libido: Guys, if you're working on a beer belly and wish you hit the pavement more, fear not: at least your sex drive might be stronger than the guy who spends hours at the gym every day. Researchers found that light and moderate exercise is associated with higher libido, while strenuous exercise is associated with lower libido. Next: finding the elusive "tipping point."
• Tully Monster Mystery Not Solved After All? Some creatures are so weird they seem to defy classification. Such is the case with the Tully monster, which scientists have mulled over since a 300-million-year-old fossil was found more than 50 years ago in central Illinois. Last year, scientists reported that the sea creature, officially known as Tullimonstrum gregarium, is a vertebrate related to the lamprey. Now, paleobiologists are saying not so fast.

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