GENERAL ZOOLOGY 



human types will probably never form a complete series. In the early stages 

 man's forebears must have existed not in large populations but in small 

 groups, rather widely scattered. Fortunately, even in the absence of skeletal 

 remains, human activities can be traced through discoveries of things that 

 man made or used, and of places where he lived, either temporarily or during 

 long periods. Artifacts, such as weapons and tools of stone or metal, crude 

 or skillful drawings and carvings, the remains of campsites and dwellings, and 

 so on, all give evidence of the manner of life, the cultural level, and sometimes 

 the physical and mental development of early man. In certain caves which 

 sheltered men for thousands of years, complete series of artifacts have been 

 found which constitute a record of cultural evolution. 



The distribution of fossil remains representing the earliest known stages in 

 human evolution indicates that mankind's center of origin was probably in 

 Asia or in Africa. Several examples of the early stages may be briefly 

 discussed (Figs. 20.8, 20.9). Australopithecus afncanus, the African ape man, 

 is the earliest known type which is truly man-like. He was evidently of 

 rather small stature and a fundamentally ape-like physique, but manv features 

 of the skeletal remains foreshadow later structural developments in the line 

 of human evolution. Australopithecus is believed to have hunted baboons for 

 food and to have killed them with crude stone weapons. The remains of 

 Australopithecus have been assigned to a period about 1,000,000 years B.C. 

 Somewhat later, about 900,000 to 800,000 b.c, Java was inhabited by a 

 group of still more man-like primates, assigned to the species Pithecanthropus 

 erectus. Other than the physical characteristics which can be inferred from 

 the relatively few fossil skulls and jawbones, little is known of this species. 

 Near Peking, China, however, more abundant skeletal and cultural remains 

 have been discovered which date from about the time of the Java ape man. 

 These were originally assigned to a new genus, Sinanthropus, but continuing 

 studies have revealed so many similarities between P. erectus and the ancient 

 Chinese men that their inclusion in the same genus seems justified. Sirian- 

 thropus pekinensis is therefore now referred to as Pithecanthropus pekinensis. 

 Whatever their correct scientific name, these men inhabited caves during a 

 warm period following the first of the great Pleistocene glaciations; they 

 hunted numerous kinds of contemporary wild animals, fashioned rough stone 

 tools and weapons, and used fire. The skulls of P. pekinensis often show signs 

 of having been roasted and broken open, presumably to extract the brain, 

 which may indicate that these people were cannibalistic. 



In response to the same factors which governed the spread of other 

 organisms from their centers of origin, early man probably migrated in small 

 groups away from the ancestral homeland. There is evidence that men 

 reached Europe during the same warm interglacial period which saw the rise 

 of Pithecanthropus in China. The Pleistocene was one of the most dramatic 

 epochs in the geologic history of the Northern Hemisphere. Four separate 

 times, between about 1,000,000 and 15,000 b.c, great glaciers slowly spread 

 southward on all the northern continents, and then slowly receded northward. 



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