By Sarah Philip – National Geographic –
For humans, aging is inevitable. But axolotls, those cute, smiling amphibians of pop culture fame, seemingly avoid this fate—to a point.
In a phenomenon called neoteny, axolotls never outgrow their larval stage, looking like oversize babies as adults. Not only do they look youthful, with feathery gills and a dorsal fin, these critically endangered Mexican salamanders experience few physical declines and diseases, and can regenerate their limbs, tail, and even organs over their 21-year lifespan.
For that reason, captive-bred axolotls—which are a light pink in color—are common research subjects for biologists, who have long been fascinated by their ability to defy aging.
