Not only elephants swim and cross bodies of water. Plenty of animal species do. Often using floating debris as rafts. Ants even make rafts (of themselves! Their own bodies). HE had examples all around him. And somehow picked up the concept. As opposed to great apes, that never did, nor, it seems, did their successors, the Australopithecines. But their successor, HE, licked it. Apparently HE made the connection, the association. Why? How? Well, I think it's safe to assume that necessity is the mother of invention. HE must have been driven by a perceived need to go through or across bodies of water. A.k.a. environmental pressure. Evolution. HE conquered pretty much all of the old world (and I'm not even ruling out HE went to America! We just haven't found him yet*).
Anyway, HE conquered the world via the coastlines. HE the beach comber, the explorer. HE was a hunter-gatherer. Probably 10% hunter and 90% gatherer. And the richest food for the gathering, with very little danger, was seafood found at the coast. Exactly where land and water meet: the waterline. You can gather shellfish, crabs, and little fish to your heart's content. Very nutritious. The landside of the waterline provides gazillions of berries and fruits. Right near the water. You can also go out further onto the land for hunting expeditions, and you do so occasionally, but not a lot, because it's very dangerous! One flick of the antlers of a thrashing giant deer could easily kill 3 men. Not to mention the multitude of great cats and other predators that roamed the savannahs and the endless forests. To them you were a mere snack.
So what about this scenario:
HE had been used for hundreds of thousands of years to follow the coastlines, and so 'conquered' far outreaches of the world. But those were MUCH different coastlines than today! 400 feet lower, minimum. That would be far out to sea of today's coastlines. So that's where by far most of HE's evidence – if any remains... – will be! So that's wehere you need to go look for it if you want to find it. Looking for HE evidence on today's landmass is a 90% wasted effort... That would have been far inland for HE. Where he rarely went.
Anyway, so HE was rambling along coastlines when suddenly the sea levels rose! Some cataclysmic meltdown event at the end of an ice age perhaps. Or a tsunami (underwater landslide). We know that those happen. And can have dramatic consequences. Anyway, whatever the cause, a sudden surge ocurred. Great disaster of course. Many died. But many surviving HE found themselves on islands. Cut off from their surviving brethren on the next island and their customary migratory routes. Cut off by water. Sea. That's how a need to cross the water arose, imo.
*not surprising as he's 400 feet down in the ocean...
Last edited by Rokcet Scientist on Mon May 11, 2009 11:42 am, edited 3 times in total.