324 



BIOLOGY FOR BEGINNERS 



has not been in a continuous straight line, like the steps upward 

 in a ladder, but that relationship is through common ancestors. 



We have certain " family resemblances " to our cousins but we 

 are not descended from them; rather, we resemble them because 



EXISTING GIBBON. 

 APES AND Asia. 

 MAN. 



MAN CHIMPANZEE. GORILLA. ORANG. 



(Homo sapient). Africa. Africa. Asia. 



Asia, Europe. 



Cro-Magnon and 

 other races. 



More primitive spe- 

 cies, human and 

 prehuman. 



Neanderthal race. 



Piltdown race. 

 Heidelberg race. 



GLACIAL OB 

 PLEISTOCENE 

 AGE. 



Primitive Gib- 

 PLIOCENE bon of Eu- 

 AGE. rope 



(Pliohylobatea). Unknown Pliocene 

 ancestors of man. 



MIOCENE 

 AGE. Earliest Gibbons 

 of Europe 



(Pliopithenu) . 



Ancestral anthro- 

 OLIGOCENE. poids of Egypt. 



(Propliopiihecius). 



Unknown ancestral stock 

 of the Old World pri- 



mates including 1 man. 



FIG. 105. Ancestral tree of the anthropoid apes and of man. 

 (From Osborn's Men of the Old Stone Age. By special permission 

 of the publishers, Charles Scribner's Sons.) 



of our common ancestors (grandparents), who contributed to the 

 inherited characteristics both of ourselves and them. 



Proof of the fact of descent and evolution is only half of the 

 battle; it remains to be shown how nature has brought about the 



