5 Most Incredible Discoveries of the Week Including smart elephants and a simple diagnostic test for Alzheimer's By Newser Editors, Newser Staff Posted Oct 12, 2013 5:43 AM CDT Updated Oct 12, 2013 9:30 AM CDT 0 comments Comments An elephant roams a 25-acre compound at the National Elephant Center near Fellsmere, Fla. (AP Photo/J Pat Carter) (Newser) – 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. Click for more incredible discoveries.