A new study has shown that for Asian elephants, grandmothers are the key to babies' survival. Most animals keep reproducing until death, though some species, such as orca whales, elephants, and humans, continue to live for decades after no longer giving birth. Because evolution is centered on reproduction, this has been somewhat puzzling for scientists: what's the use in living to old age if you're no longer producing offspring?
To help answer this question, a team of Finnish researchers observed Asian elephants in Myanmar. What they found was astonishing: if a grandmother lived in the same area as her grand-calf, that calf had eight times lower risk of death. The calf's mother, likewise, produced more offspring, ostensibly because she had less work when it came to raising her own calves and so was free to bear more. They also found that the more calves the grandmother had given birth to, the bigger the effect she had on her grand-calves, showing that more experience in motherhood made her a better grandmother.