494 



ELEMENTARY BIOLOGY 



The larger brain, carrying with it possibihties of learning, 

 imitating, and planning, is perhaps the most important advance 

 made over the simian ancestors (see Fig. 255). 



Fig. 256 is a diagram which shows the distinctive traits 

 of several ancient specimens supposed to represent different 

 stages in the evolution of the human species. Fig. 258 repre- 

 sents restorations of some of 

 these primitive forms ; from 

 these we can get an idea of 

 how some of the intermediate 

 ancestors probably looked. 



Fig. 257. Fossil remains of man 



The pieces of skull, jawbone, and tooth 

 found in England at Piltdown in 191 1 rep- 

 resent a lower type of human being than 

 any that had been previously discovered 



512. Evolution and man. Fifty 

 years ago much of the discussion 

 among thinking people centered 

 around the question of the validity 

 of the evolution theory as applied 

 to man. There were many who 

 were prepared to believe that 

 evolution has taken place among 

 plants and lower animals, but 

 who hesitated to accept the same 

 explanation for the appearance of man upon earth. One of the 

 strongest objections urged against the theory was the fact that it had 

 been impossible to produce a complete record of a graded series con- 

 necting man of to-day with his supposed non-human or prehuman 

 ancestors. This argument of the " missing link " carried a great deal 

 of weight with people who did not appreciate how unlikely it would 

 be for complete series of specimens to be preserved through geologic 

 times. Of the millions of human beings and other vertebrates that 

 die in a given region during a century, how many skeletons are likely 

 to remain sufficiently intact to be recognized from ten thousand to 

 fifty thousand years later ? From a scientific point of view it would 

 be sufficient if the scattered pieces found at widely different levels 

 (geological ages) do actually fit in with a supposed series. 



The few bones found in Java by Professor Dubois in 1894 fit 

 into such a series in a very satisfactory way. The type of animal 

 to which these bones belong was named Pitheca?iihropiis erectus, and 



