Hope of Earth by Piers Anthony

twisted into rope would have been extremely useful, and nets could have served in lieu of skins in the manner shown here. The technology was as yet clumsy, and it left no trace in the early archaeological record because it rotted away, but surely full-fledged cloth did not spring fully developed from nothing. The artifacts of vine fiber may have served for a hundred thousand years before the refinements of cloth developed. The string skirt itself has survived from three or four thousand years ago, but we know it goes back beyond 20,000 years because its semblance appears on the ‘“Venus” figurines (of which more later). It was as described: a stunningly sexy outfit for nubile young women, and a great enhancement for the triple ploy strategy in the covert contest between men and women. Who needed cloth, at this stage? But eventually the marvels of cloth would come. Whether any such thing as the string skirt was used 150,000 years ago is wildly conjectural, but it is possible, given the nature of the triple ploy. Today it manifests as the provocative miniskirt.
    But why such a giant brain? Once mankind managed to forage in the hot savanna, and to scavenge for richer food, he would seem to have had enough intellect to survive. Once he adapted his mating scheme to provide support and protection for women, the better to ensure survival of offspring, no further intelligence was required there either. Why keep building the brain beyond any likely need to compete with other species? This is where the arms race figures. Mankind did have constant competition for the resources of his ecological niche: variations of his own kind. They were constantly fissioning off, setting up rival communities, and they had much the same abilities he did. So who prevailed? That subspecies that could do it best. For a time it seemed that bigger and stronger men were the answer, but in the end it seems to have been the gracile ones with more versatile intelligence and speaking abilities. So the race was between brains, and in the end the best brain won. Ours.

Chapter 5
N UMBERS
    Numbers are important. If there are too few members of a given species, it dies out, lacking a viable breeding community. If there are too many for the habitat to sustain, there is apt to be competition and starvation. But even between those extremes, there are dynamics that make a real difference. This is especially true for mankind, a social creature, A lone person may survive for a year, A band of twenty-five is viable for perhaps 500 years if it interacts with other bands so as not to become inbred. A band of 100 is apt to fragment, because of internal quarreling. So most bands of hunter-gatherers range between twenty and seventy people. That may be considered the basic unit of human society. But there must be exchanges between bands, for breeding, trade, and information. Thus they will be part of a larger group, or tribe, whose total number seems most viable at about 500 or 600.
    Suppose some way were found to increase the size of human bands, so that internal dissent did not break them up when they became larger than the normal range? A larger band would have more leverage than a smaller one, and might be able to take over the best hunting and foraging territories, and prosper further. Such an advantage of numbers would enable particular bands to survive better, especially in competition with others of their kind. And it seems that such a way was found.
    In the prior volumes there was a mystery: why did physically modern human beings emerge from Africa about 100,000 years ago, then remain in the Levant for 50,000 years before proceeding farther? Now it is known that they did not pause, physically, and probably not linguistically. They moved on to southeast Asia, where their traces have been dated back to about 70,000 years ago, and on from there. They seem to have stayed generally clear of the coldest or most mountainous terrain in that 50,000 years, however, which may