Ancient Rings: 5 Most Incredible Discoveries of the Week

Crafty Neanderthals and a new theory on the origin of Alzheimer's were among the biggest discoveries of the week:

• Deep In a Cave, Neanderthals Did Something Remarkable: A caver deep inside France's Bruniquel Cave found something wild: two stone rings up to 16 inches high intentionally made from pieces of chopped-up stalagmites. The wilder thing: Scientists think they were made by Neanderthals some 176,500 years ago, a feat that changes what we know of early humans.
• Superbug Found in US May Be Seriously Bad News: Researchers for first time have discovered a superbug in a US patient that is resistant to so-called last-resort antibiotics. The finding in "patient zero" in Pennsylvania has the director of the CDC talking about a "post-antibiotic world."

• Study Floats Provocative Alzheimer's Theory: A new study out of Harvard puts forward what's being called a "startling hypothesis" about Alzheimer's. The research suggests that old infections in the brain—or, more specifically, the body's attempt to fight them off—may be at the root of the disease. It revolves around that telltale plaque.
• Wrong Crocodiles Found in Florida: Huge, man-eating crocodiles may be hiding throughout the Florida wilderness. DNA testing on three young crocodiles caught between 2009 and 2014 confirmed them to be Nile crocodiles native to Africa, and this could be bad news for the Everglades.
• It's OK to Let Babies 'Cry It Out': While it may be stressful—or at least guilt-inducing—for new parents, letting a baby cry it out before bed may actually be less stressful for the infant, according to a new study. But parents who don't buy in to the theory shouldn't stress.

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