CREATION BY EVOLUTION 



is in itself sufficient to show that Australia has been geo- 

 graphically isolated for a long time, so that mammals of the 

 higher, more advanced groups were unable to reach it. 



The fact that 2o5logical regions, as pictured on the map, 

 when marked by differences of colour, seem to make a patch- 

 work or a meaningless pattern on the map is due to the long, 

 varied, and complicated changes in the geography of the 

 regions and in their climate as recorded in their geological 

 structure. Land areas that are now united were for ages 

 separated by arms of the sea, and lands that are now sep- 

 arated were formerly united. Not very long ago, as geo- 

 logical time is reckoned. Great Britain and Ireland were 

 joined to each other and to the continent of Europe, and the 

 North Sea was a wide terrestrial plain, which stood not far 

 above sea level. At about the same time the great islands of 

 the East Indies were parts of the mainland of Asia, from 

 which they became separated at different times. Borneo, 

 Sumatra, Java, Celebes, the Philippines, the Japanese group, 

 and the Kurile Islands were once joined to Asia. In the 

 course of the ages Alaska and Siberia have been often con- 

 nected and as often separated by uplift and depression of the 

 land, and North and South America were brought together 

 by the Isthmus at a relatively late period. Before that period 

 the two continents had long been separated by a broad sea, 

 which covered the site of the Isthmus and most of Central 

 America. 



We must also note the remarkable changes of climate to 

 which the rocks and fossils bear unequivocal testimony. 

 During the greater part of the Tertiary period the climate of 

 the earth was mild and genial, a fact indicated by the fossil 

 plants of the Arctic regions. This climate gradually gave 

 way to one that was colder and that culminated in the 

 glacial period, when so many lands were buried under sheets 

 of moving ice, as Greenland is to-day. 



[86} 



