杏吧原创

NOW we know how we should picture the first modern humans: dining on hippo and catfish on the shores of an African lake.

The discovery of three remarkable human skulls, modern in appearance but for a dash of ape in the brow and jaw, seems to settle one of the longest-running and most acrimonious debates in palaeontology (鈥淭he dawn of Homo sapiens鈥�). For years, most experts have argued that our species evolved just once, in Africa, and swept across the globe, ousting more primitive relatives such as the Neanderthals as it went. But a vociferous minority have insisted that we emerged in many places at once. This second view has recently been losing ground, but its advocates have always made much of what they regarded as a suspicious lack of fossils with near-modern features from Africa dating from the appropriate time.

The new fossils plug this gap. So are the critics nobly conceding defeat? Are their opponents congratulating them for having spurred the search for the clinching evidence? Not a bit of it. The discovery changes nothing, say supporters of the 鈥渕ulti-regional鈥� theory of human origins. In its latest form, they say, this theory is perfectly consistent with the main ancestors of modern humans evolving in Africa. Its key difference from the rival 鈥渙ut of Africa鈥� hypothesis? Merely to emphasise the possibility of these humans interbreeding a little with the more ancient types they encountered en route to world domination.

It is often said that bitter disputes between scientists pushing rival theories only fade when their protagonists die. Some disputes, however, seem to end up being arguments over almost nothing.