5 Most Incredible Discoveries of the Week

Elephants smart enough to understand what humans mean when they point, and an Alzheimer's test that's probably in your kitchen highlight this week's discoveries:

• Elephants Understand When We Point: Researchers have found that when humans point a finger, elephants understand exactly what they're doing and what it means. Other animals can learn the skill, but elephants seem to have been born with it.
• Alzheimer's Test: Can You Smell Peanut Butter? How's this for a low-tech way of diagnosing Alzheimer's: sniffing peanut butter. Researchers at the University of Florida have discovered some merit to the bizarre-sounding notion. Those who have trouble picking up the scent with the left nostril might have reason to worry.
• Male Marsupials Die After Marathon Mating: Some male marsupials have quite the end-of-life experience: They "mate themselves to death," explains the lead author of a new study in the journal PNAS. The trait is all about trying to win the reproduction sweepstakes.
• 2047: New Climate Change Turning Point: Feeling the effects of climate change, but not worrying too much yet? Mark this year: 2047. That's when, for most of the world, the coldest year in the future will be hotter than any in recorded history, according to a new study.
• Archaeologists Find 4K-Year-Old Brain: Archaeologists in Turkey have uncovered one of the oldest human brains ever found. The 4,000-year-old specimen was found in Seyitömer Höyük, a Bronze Age settlement, and researchers think its owner was likely killed when an earthquake buried him under rubble.

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