240 INTRODUCTION TO EVOLUTION 



Le Gros Clark (1959) also suggested that the European Heidelberg jaw, 

 long a bone of contention, may have belonged to a pithecanthropine, but 

 other investigators see Neanderthal affinities in this jaw (Fig. 11.11), and 

 at any rate far-reaching conclusions based upon one jaw are dangerous. 

 Thus we see that in about the middle of the Pleistocene, some half-mil- 

 lion years ago, there lived in Asia and probably other regions people who 

 walked upright, as did the South African australopithecines, but who were 

 larger in body and brain than were the South African forms. Judged by 

 modern human standards their brains were still small, however. Were 



these small brains indicative of markedly low in- 

 telligence? To answer this question we would wish 

 more information about their culture than is avail- 

 able to us. Evidence from the caves in which the 

 remains of the Peiping men were found indicates 

 that these people manufactured stone tools of 

 quartz and that they used fire. They were hunters, 

 FIG. 11.11. The Hei- and judged by the cracked bones and skulls found 

 delberg jaw. (From associated with their remains they regarded brains 



Romer, Vertebrate Pa- , , ■ i j i- • t-, 



, , , ,, . . , and bone marrow as especial delicacies. There is 



leontology. University of ^ 



Chicago Press, 1945, p. some evidence that human brains and marrow were 

 357.) as welcome articles of diet as were those portions 



of lower animals. Le Gros Clark ( 1949-1957) sug- 

 gested that their habits may have been somewhat similar to those of head- 

 hunters of modern times in Borneo and elsewhere, and that they may have 

 been almost as advanced culturally as are some of the less civilized peoples 

 of today. But they were back near the beginning of being human; as Gregory 

 (1951) expressed it, "Whatever the inherent possibilities of the Javan and 

 Peking people's brains may have been, their bank of learning and tradi- 

 tion was still in a relatively early stage of accumulating a favorable bal- 

 ance." 



Transitional Forms 



We have now reached about the midpoint of the Pleistocene in time, and 

 in human development we have reached a stage in which the brain aver- 

 aged smaller than that of Homo sapiens though some individual brains 

 were within the range of variation exhibited by the latter. Teeth were still 

 large and jaws were chinless. Skulls were flattened and had heavy eye- 

 brow ridges. This brings us to a portion of the Pleistocene from which 

 human remains now known are few and fragmentary. But such as they are 

 they exhibit trends from the Pithecanthropus-stage toward the two types of 



