212 



EVOLUTION, GENETICS, AND EUGENICS 



Fig. 42. — Three aquatic types of vertebrate, to illustrate convergent adapta- 

 tion of three wholly unrelated forms of marine life. All three show the fusiform 

 body, median and paired fins, though the skeletal structures are radically differ- 

 ent. A, shark (Pisces); B, ichthyosaur (Reptilia); C, porpoise (Mammalia). 



{From Newman, after Osborn.) 



