CHAPTER XXX 



PREHISTORIC MEN 



At a time when remains of apelike men were unknown, Darwin postulated 

 that such creatures must once have existed. Before his death in 1882, the 

 first fossil men had been recognized, and since 1895, scarcely a year has 

 passed without significant new finds. Our own species, Homo sapiens, has 

 been traced far back into the Pleistocene, and other now extinct kinds of 

 men have been discovered in Europe, Africa, and Asia. The known fossils 

 are more and more apelike as we go back in time, although even the oldest 

 are still "men," if we define "man" as a big-brained anthropoid built 

 much as we are who had well-formed hands and made recognizable tools. 

 Future discoveries will almost certainly bridge the remaining gap between 

 the most apelike men thus far found and the manlike Pleistocene apes 

 described in the last chapter. 



The Pleistocene epoch. Although man is presumed to have arisen 

 during the Pliocene, his known history is wholly comprised within the 

 Pleistocene epoch — the "great ice age." This latest episode in earth 

 history was a time of unrest. Continents were uplifted, mountain making 

 was active in many parts of the world, and climates fluctuated extremely. 

 Four times vast ice sheets spread over the northern lands, and four times 

 the ice melted away. The temperature and rain belts shifted their posi- 

 tions, and with them moved whole floras and faunas. The last melting 

 of the ice took place only a few thousand years ago. We speak of the time 

 since then as postglacial and designate it as the Recent epoch; but this 

 "epoch" is perhaps no more than a warm spell in the Pleistocene winter. 

 According to one theory of glacial causes the ice will be back in some 

 50,000 years. 



The Sequence of Glacial and Inter glacial Ages. It is well established 

 that there were four major Pleistocene glaciations, separated by warmer 

 interglacial ages. In each glacial age ice sheets arose in the north and 

 advanced southward over Europe and North America. No two glaciations 

 had exactly the same limits, but in general the ice covered Europe as far 

 south as Germany and England, and North America to the present 

 Missouri and Ohio rivers. Between glaciations climates became at least 



488 



