....Not plants that were entirely indigenous to Africa.
Or alternatively the presence of large stone carved sculptures on the North East coast of South America, that have undeniably negroid features. You can't be me, I'm taken
Actually, it's quite feasible to cross the Atlantic by dead reckoning (speed * time passed = distance, and direction by a corrected compass) alone, with reasonable accuracy. In the 70s and 80s, before everyone had GPS, quite a few sailors didn't want to bother with a sextant, and just crossed that way.
The error upon arrival depended a lot actually on the speed of the boat : the faster the boat, the less chances of small errors on boat/current speed/course building up to result in large errors upon arrival.
Regarding the mummies with nicotine and cocaine traces, that's still a matter of dispute -- contamination, chemical products during mummification, and African plants now gone are among the other possibilities. For the latter speaks that there is wild tobacco discovered somewhere in the South of Africa, and that the formation of the Sahara definitely must have caused some extinctions.
If there was regular trade with America, there is also the question of a trace in the historical record. There is one candidate, Punt, unfortunately the description doesn't fit America. It does fit India though, and the route there does involve one crossing of high seas (the Arabian Sea).
As far as I know, the "undeniably negroid features" of Olmec heads is something peddled by Mormons and some US Black nationalists, no more science. *Lunatic*, n. One whose delusions are out of fashion.
http://www.crystalinks.com/olmec.html You can't be me, I'm taken
I suppose it comes down to asking whether plants that might exist but have never been found and have left no trace are more likely than voyages that might exist and have never been found.
Olmec vs Egyptian tie-ins are a bizarre suggestion archaeologically. There's one big similarity - pyramid building - but not much else.
If the two cultures were closely related, you'd have expected some overlaps in imagery, writing (hieroglyphics, especially) and so on. But there's really next to nothing.
If you allow for some trade, it's possible Olmec visitors to Egypt might have seen the pyramids and though 'Good idea! Let's do that too!' But I think it's unlikely there was ever more of a connection than that.
So it remains a mystery. (And probably always will.)
