ANIMAL HABITATS 21 



land masses than are those of the tropics. In both 

 Canada and Siberia, lynxes, wolves, foxes, bears, 

 martens, gluttons, weasels, minks and badgers may 

 be found. It is true that differences occur. The 

 American puma is replaced by the Siberian tiger; 

 the wildcat of Europe is distinct from that of 

 America. The skunk is absent from Europe 

 while we lack the Siberian wild dog and the Euro- 

 pean wild hog. However, in the main the animal 

 life of these northern forests is much more nearly 

 similar all around the world under similar con- 

 ditions, than is that of the tropics. 



The greater similarity of animal life in similar 

 regions at the north of the different land masses 

 as compared with the tropics does not mean that 

 the habitats there are more similar. Rather, the 

 indications are that the similarities are due to the 

 fact that the two areas have been separated for a 

 shorter time and less effectively than have the 

 tropical forests. There is good evidence that in 

 relatively recent times, geologically speaking, 

 close connections existed between Siberia and 

 Alaska across the Behring Straits. Close land 

 connections between the different tropical lands 

 of the world, if indeed they ever existed, have 

 been much more remote in geological history. 



In other words, these cases demonstrate that 

 similarity in animal habitats does not necessarily 



