The brains of our closest relatives, unlike our own, do not shrink with age.
The findings suggest that humans are more vulnerable than chimpanzees to age-related diseases because we live relatively longer.
Our longer lifespan is probably an adaptation to having bigger brains, the team suggests in their Proceedings of the National Academy of Sciences paper.
Old age, the results indicate, has evolved to help meet the demands of raising smarter babies.
As we age, our brains get lighter. By 80, the average human brain has lost 15% of its original weight
Not long ago, while waiting for the #7 at the bus stop across the street from a funeral home, I watched an ancient woman killing a lone ant with the rubbery end of her walking stick. The ant was ambling away from us, heading toward a bush at the end of the sidewalk. The old woman spotted it, came alive, and tried to hit it (missed), and hit it again (missed). Finally she hit it. Finally it was flattened and severed.
Because there was no real reason to kill this ant—it wasn't in her house or threatening her in any way—I read it as an act of existential revenge for what life had done to her body—made her so old, so slow, and constantly feeling pain in the joints. For her, life was no longer something to celebrate (watering flowers, feeding fish) but to hate (killing little bugs for no good reason). This BBC report, however, has got me thinking: Did a soft brain play a role in the killing of that ant?