536 THE CHANGING GENERATIONS 



organisms, and he could never become abundant. By one estimate there 

 were never more than 7 million people in the whole world in Paleolithic 

 times. Agriculture released man from the control of natural food chains. 

 Labor could make more food, and "with every mouth God sends a pair 

 of hands to feed it." The Neolithic peoples began to multiply (Fig. 34.1) 

 and spread, pushing some of the Paleolithic people ahead of them, mixing 

 with others, and transmitting the new economy to friend and foe so that 

 they also became a part of the Neolithic populations. 



Thus began the great change in man's evolutionary trends. In place 

 of isolation and increasing differentiation, now movement of populations 

 and racial mixture became dominant processes over most of Eurasia. 

 Mediterraneans spread over much of Europe and into India and central 

 Asia; Mongols came out of Asia into Europe; the Nordic wanderings are 

 a matter of record. Much later the "Whites" erupted out of Europe into 

 the Americas, Australia and South Africa, exterminating or mixing with 

 the native populations. Large numbers of African Negroes were brought 

 as slaves to the Americas. Their descendants now dominate many of the 

 West Indian islands, are thoroughly mixed with "Whites" and American 

 Indians in Brazil, and are in process of being amalgamated with "Whites" 

 in North America. In Mexico, Central America, and much of South 

 America the populations are still predominantly Indian but contain a 

 variably large "White" admixture and in some countries considerable 

 Negroid. All over the world this mixing process has been going on to a 

 greater or lesser degree, and it will doubtless continue. Races are merging 

 and becoming less distinct than ever, but this does not mean that men 

 will all eventually be alike. As the world fills up with people, mass migra- 

 tions and large scale mixing will probably diminish in importance, and 

 the various racial mixtures may have a chance to become stabilized in 

 new patterns. Individual differences within populations will probably 

 increase, since the common gene pool from which each individual draws 

 will contain a greater variety of variable genes. 



THE ZOOGEOGRAPHY OF MAN 



Everything points to Asia as the region where the great groups or sub- 

 species of man arose. Broadly viewed, we see them arranged radially, 

 in sectors extending out from the Asiatic mountain mass. The "Whites" 

 are to the west, in southwestern Asia and on both sides of the Medi- 

 terranean. The Mongoloids are on the north and east, and surround the 

 Pacific. The Negroids lie to the south on both sides of the Indian Ocean, 

 interrupted in southern Asia. 



Now let us look more closely at the continental radii. In the European 

 peninsula remnants of the old Paleolithic or proto-European people lie 



