CREATION BY EVOLUTION 



are now found. Here also many migrations back and forth 

 between the two continents may be traced by the record of 

 the rocks, and these migrations and counter migrations 

 took place at widely separated geological dates. Many 

 American mammals are the modified descendants of migrants 

 from the Old World. Some came to America at a very 

 ancient time; others came recently and are so little modified 

 that naturalists disagree as to whether they should be 

 assigned to European species or not. In short, our under- 

 standing of the distribution of existing mammals is depend- 

 ent upon our knowledge of their history, and v/here that his- 

 tory is known the distribution is self-explanatory. If the 

 doctrine of special creation is true, this knowledge is illusory, 

 for according to that doctrine the modern species were sep- 

 arately created and therefore have no connection with the 

 ancient species that look so deceptively like the ancestors 

 of the living forms. 



North America was separated from Asia at a very late 

 date, as geological time is reckoned, and hence there is rela- 

 tively little difference between the animals of the American 

 and the Eurasiatic division of the Palaearctic region. The 

 only large mammal that is found in the American and not in 

 the Eurasiatic division is the musk-ox, but until a very recent 

 period that peculiarly Arctic creature dwelt in Siberia and 

 roamed as far westward as Great Britain, which was then a 

 part of the mainland. 



The distribution of mammals on the continents finds a sat- 

 isfactory explanation in the theory of evolution and only in 

 that theory, but the facts of island life furnish even more 

 remarkable and more convincing testimony of the truth of 

 that theory. Islands have been formed at different dates, 

 some rising from the sea within the last few years, others 

 having a history that goes back to the remotest geological 



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