Gary L #GreenParty #SaveOurNHS #BrexitShambles

Everyone assumes we're smarter than our Ice Age ancestors, and the biggest human brains ever measured belong to them, not us. For two million years the human brain grew. Then, around 20,000 years ago, it went into reverse. The Homo sapiens with the largest brains lived 20,000 to 30,000 years ago, from Europe down to South Africa. Barrel chests, heavy jaws, enormous teeth, and bones thicker than anything walking around today. Since then the average male brain has lost around 150 cubic centimetres, from about 1,500 to about 1,350. Roughly 10%. A tennis ball's worth. Women's brains have shrunk by the same proportion. We comfort ourselves that we must be cleverer anyway. We have smartphones, satellites and supermarkets. Not one of us invented them, and not one of us could build one. The Ice Age hunter made everything he owned. He knapped razor-edged blades from flint. He sewed fitted clothing with needles carved from bone. He read tracks, wind and season, and followed reindeer, horse, bison and mammoth across hundreds of miles without a map. Then he crawled into a cave and painted them from memory, by the light of a lamp burning animal fat, so well that 17,000 years later we queue to see the replicas. Our knowledge lives in a phone. His lived behind his eyes. The explanations for the shrinking run from smaller bodies to self-domestication to life in crowds. Nobody disputes the timing. It tracks the end of the great hunts, the spread of farming, and the packing of people into villages and towns. Every domesticated animal ends up with a smaller brain than its wild ancestor. The wolf's is bigger than the dog's. The dog isn't dimmer by nature. It has just never had to find its own dinner. The biggest brains in human history were fed by hunters who followed the herds across the tundra. Ours were raised on toast, and we're the ones calling them cavemen.