THE ORIGIN OF SPECIES 



Matthew's Theory on Climate and Evolution. Matthew based his 

 ideas on climate and evolution upon his long experience as a geologist and 

 mammalian paleontologist. He believed that the continents and the ocean 

 basins were substantially permanent, and that theories involving conti- 

 nental drift, lost continents, or former land bridges across deep oceans 

 were not in accord with known geological facts. In contrast, the climate 

 of the world has alternated throughout the history of the world between 

 warm, moist phases in which a mild climate prevailed throughout, and 

 severe, arid phases in which climatic zones difiPered one from another. In 

 the warmer phases, shallow seas covered much of the continental low- 

 lands, and tropical organisms could inhabit northerly regions. But in 

 times of arid, zonal climates, the polar regions were cold, the continents 

 were elevated, glaciation might occur over large portions of the northern 

 continents, and only the tropics remained mild. By the use of polar pro- 

 jection maps (Figure 113), he showed that the great land masses of the 



FIGURE 113. Polar Projection Map of the World. (Redrawn from 

 Matthew. ) 



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