Scientists studying an astonishing find of 300,000-year-old human remains in a Pyrenees cave have solved one problem of the sex war - the female human ancestor was only a little smaller than her male mate. Wilma Flintstone, in other words, was nearly always a match for her Neanderthal husband, Fred.
The quarrel, resolved today in the US journal, Science, has been raging for decades. In other related species - monkeys and apes - females are much smaller than males.
"Human males are perhaps 10 per cent larger than females. If you go to gorillas, you are talking about 50 per cent bigger," said Dr Chris Stringer, of the Natural History Museum in London.
Scientists believed that Homo erectus males two million years ago, or Neanderthal males 400,000 years ago, were much bigger than their females, but it was a largely theoretical argument.
Anthropologists built up their picture of the past from single skeletons in one place and perhaps a skull or even a broken shinbone in another. There wasn't enough evidence to answer the question until several years ago, when scientists exploring a cave in the Pyrenees unearthed the remains of at least 32 humans who lived and died 300,000 years ago.
Scientists from Madrid, Burgos and Tarragona in Spain told Science that they examined variations in sizes of skulls and other bones. Normally, palaeontologists look at the size of the bone and decide which sex it belongs to. But, with a treasure trove of skulls, it didn't matter which were male, which female; they only had to look at the variation. And this was much the same as it is now, for Homo sapiens.