A Story Outline of Evolution 



is an Instance where we can see the processes of Evolution 

 still at work in casting off a useless organ. 



The whale furnishes one of the most striking examples 

 of adaptation because it has passed through all the stages 

 of animal development until it reached the highest class and 

 then, either from choice or necessity or both, it has returned 

 to the environments of its ancient ancestors. During its 

 ascent, it developed all the organs common to the mam- 

 malian class — a four chambered heart, warm blood, limbs 

 and lungs, ears, a nose and perhaps a coat of hair. It gave 

 birth to and suckled its young and lived for millions of years 

 in much the same manner as did its contemporary cousins. 

 But there came an urge and it left the land for which its 

 organs had been patterned and returned again to the sea. 

 Millions of years had been required to build up these land 

 organs and now other millions of years will be required to 

 throw them off. Evolution Is doing this work of destroying 

 the useless organs without In any manner Interfering with 

 its daily tasks. It still gives birth to and suckles its young 

 but we have already seen that its young obtains Its milk in 

 an automatic "squirt gun" fashion. It Is gradually assum- 

 ing the form of Its fish ancestors but Its warm blood Is kept 

 warm by an abundance of fat beneath which Its blood is cir- 

 culated. Its teeth have disappeared and, In their stead, a 

 new substance like a flexible bone has been substituted suit- 

 able for gathering Its food supply. They have developed 

 huge fins or paddles and a horizontal tail fin as a means of 

 propelling their huge bodies through the water and arising 

 quickly to the surface. Burled beneath the smooth skin of 

 their fore paddles may still be found the vestigial remains — 



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