THE ORIGIN OF SPECIES 



3rcl molar 



vermiform 

 appendix^ 



pyramidalis 

 muscle 



seg menial 

 muscles 

 on abdomen 



caudal 

 vertebrae 



Figure 97. Some Vestigial Charac- 

 ters OF Man. (After Kalm, from Storer 

 and Usinger, "General Zoology," 3rd 

 Ed., McGraw-Hill Book Co., Inc., 

 1957.) 



of the biology of the species. In man, cooperative and competitive aspects 

 exist side by side. Some nineteenth century critics beheved that this in- 

 vahdated natural selection. Tliis, however, was an error, for cooperation 

 itself may have selective value, increasing probability of survival. The 

 elaborate societies of ants have certainly aided these species in competi- 

 tion with others. The looser societies of grazing animals, like deer or cari- 

 bou, provide mutual protection against predators. And surely it is obvious 

 that human cooperation in many spheres is partially responsible for the 

 great success of man. Thus animal cooperation, superficiallv contradictory 

 to natural selection, is actually one of its products. 



REFERENCES 



Brower, Jane v. Z., 1958. "Experimental Studies of Mimicry in Some North American 

 Butterflies," Evolution, 12, 32-47; 123-136; and 273-285. The technical report on 

 an excellent series of experiments. ( Bates, Ford, Miiller. ) 



CoTT, H. B., 1940. "Adaptive Coloration in Animals," Methucn & Co., Ltd., London. 

 An extraordinarily comprehensive review. ( Swinnerton, Sumner. ) 



Dobzhansky, Th., 1951. "Genetics and the Origin of Species," 3rd Ed., Columbia 

 University Press, New York, N.Y. (Dice, Quayle, Stakman, Sukatchew, Timofeeff- 

 Ressovsky. ) 



Fisher, R. A., 1930. "The Genetical Theory of Natural Selection," Oxford University 

 Press. A classic. 



McAtee, W. L., 1932. "Effectiveness in Nature of the So-Callcd Protective Adapta- 

 tions in the Animal Kingdom, Chiefly as Illustrated by the Food Habits of Ncarctic 

 Birds," SniitJisonian Misc. Collections, 85, 1-201. An excellent example of the evo- 

 lutionary biology of the Agnostic Period. 



Montagu, M. F. Ashley, 1952. "Darwin, Competition and Cooperation," H. Schu- 

 mann, New York, N.Y. A systematic study of the role of cooperation in evolution. 



Schmalhausen, I., 1949. "Factors in Evolution," McGraw-Hill Book Co., Inc., New 

 York, N.Y. Develops the role of selection as a conservatixe factor. 



252 



