264 INTRODUCTION TO EVOLUTION 



resembles a flying squirrel in having membranes stretched between fore 

 and hind limbs to provide planes useful in gliding. 



Of the other marsupials of Australia and neighboring Tasmania we may 

 mention hare wallabies, little kangaroolike creatures with habits much like 

 those of our rabbits, the Tasmanian wolf, a carnivorous marsupial resem- 

 bling true wolves in many respects, the Tasmanian devil, a carnivorous 

 creature reminiscent of our badgers, and the banded anteater, a small 

 marsupial with pointed snout and long, sticky, extensible tongue, the hall- 

 marks of anteaters of whatever relationship the world over. In sum, the 

 marsupials of the Australian region furnish a most striking example of that 

 adaptive radiation discussed in an earlier chapter (pp. 26-29). 



Eurasia and North America 



The foregoing discussion reveals that the three continents of the South- 

 ern Hemisphere present marked contrasts in animal inhabitants. In the 

 Northern Hemisphere, however, we find the contrasts much less striking. 



The faunas of Eurasia and North America abound in animals which are 

 either identical or closely similar. Confining our discussion to mammals, we 

 may mention such widely ranging groups as deer, cats, wolves, foxes, otters, 

 weasels, badgers, moles, shrews, rats, and mice. Many of these are found 

 not only in the two northern continents now under consideration but also 

 in many other regions of the earth. Restricting our attention to mammals 

 more distinctive of the two northern land masses, we may mention some 

 of the hoofed animals common to both: ( 1 ) bison, sometimes called buffalo 

 in this country; (2) the large deer called moose in this country, elk in 

 Europe; (3) the wapiti, frequently called elk in this country, closely similar 

 to the stag of Europe (see comments on "common" names! p. 308); (4) 

 reindeer or caribou; (5) the North American mountain goat, closely akin 

 to the chamois of Europe; (6) the mountain sheep or bighorn. 



Bears afford another example of the similarity of mammalian life on the 

 two northern continents. Aside from one species inhabiting the Atlas Moun- 

 tains of North Africa, and the peculiar spectacled bear living in the Andes 

 of South America, bears are confined to these northern continents. Among 

 the various species the polar bear is familiar to all as a denizen of circum- 

 polar arctic regions. 



Both northern continents have beavers, lynxes ("bobcats"), varying 

 hares (brownish gray in summer, white in winter), and those odd little 

 relatives of hares and rabbits, the pikas or conies. The list might be 

 greatly extended, as well as expanded to include birds and other animals. 



