> Such was the argument before the discovery and recognition of
> the megalithic centers in the Supe Valley and the earlier
> settlements along the Pacific coast. Betty Meggers was the
> chief antagonist toward increasing evidence of widespread
> farming not based on maize but horticultural encouragement of
> native species of nut and fruit trees. Rcall that Caral was
> constructed by a pre-agricultural, pre-ceramic people and it
> predates the construction of the Great Pyramid. Part of the
> problem with Meggers' and others' scenario of small hunter
> gatherer groups being incapable of large scale food production
> and civic projects lies in the previous lack of recognition of
> farming strategies quite unfamiliar to Europeans. The
> phenomenon of terra preta, artificial earth, was such an
> unrecognized strategy until the last decade.
> From Wiki:
> By the first millennium, South America's vast rainforests,
> mountains, plains, and coasts were the home of tens of millions
> of people. Some groups formed permanent settlements. Among
> those groups were the Chibchas (or "Muiscas" or "Muyscas"),
> Valdivia and the Tairona. The Chibchas of Colombia, Valdivia of
> Ecuador, the Quechuas of Peru, and the Aymara of Bolivia were
> the four most important sedentary Amerindian groups in South
> America. From the 1970s, numerous geoglyphs have been
> discovered on deforested land in the Amazon rainforest, Brazil,
> leading to claims about an ancient complex Amazonian
> Charles C. Mann goes into greater detail how early
> misperceptions of the populations and strategies of the
> pre-columbian Americas is in need of extensive revision in his
> book 1491, which we have discussed here previously.
> As we have seen with Gobekli Tepe this revision is not limited
> to any one continent. Extensive Pre-Inca stone ruins abound in
> South America and have been noted by Europeans ever since
> Francisco de Orellana's exploration of the Amazon in 1541-1546.
> Such blanket denials of large populations and civic
> achievements in pre-columbian South America can no longer go
> without challenge from empirical evidence.
> > The Americas for the most part are nutrient-poor. Huge
> > of food on the scale you're describing just weren't grown.
> > There were no draft or domesticated animals to use as a
> > source or to pull plows. Now, farming did occur, of course,
> > maize was one of the few choices they had. Wild maize was
> > tiny, and only over very long periods of time--along with
> > genetic modification--did it become the crop we know today.
> > Best guess is that it took nearly 10,000 years to domesticate
> > and diversify genetically.
> > All of these factors would have led to an inability to
> > huge populations in one place.
I deleted that post because it wasn't in any way relevant to South Africa, but that's okay, I'll answer. :))
I've no doubt that there were millions of people, especially in South America, at the end of the last Ice Age. Now, nut and fruit trees I can go along with for obvious reasons: the nuts would be a good source of protein and fats, while the fruits would give you a lot of your vitamins and carbohydrates, and are also a source of water. Beans and squash are also great sources of macro- and micronutrients, and we do know that they grew these as well.
As with a lot of things, necessity is the mother of invention. We do know that a mass extinction took place in the Americas c. 12,000 years ago. Gone was the big game they may have been used to hunting. The fact that agriculture began on both sides of the Atlantic at roughly the same time (more or less) argues for something happening at this time to make it necessary. They had to find other ways to feed themselves or starve. The problem is that there weren't enough varieties of wild and native cereals in the Americas to get a large operation going, and the lack of draft animals in such a mountainous and extreme topography would have made it extremely difficult. And nowhere did it happen overnight. It took a really long time for agriculture to get going, and who knows how many fits and stops there were along the way. Nature might abhor a vacuum, but it takes a long time to fill it.
You do have to wonder how the sweet potato got to Papal New Guinea, though. :))