CREATION BY EVOLUTION 



because they yield the concentrated foodstuffs that made 

 possible the evolution during Tertiary time of the mam- 

 mals — the horses, cows, hogs, sheep, etc. — on which depend 

 our agriculture and consequently our civilization. 



The earliest floras of the Cenozoic era — the age of mam- 

 mals and of flowering plants — are marked by a great mod- 

 ernization of forms. They consisted in large part of 

 ancestors of forms that exist today, and their chief 

 scientific interest lies largely in the great differences in 

 geographical distribution which they show in contrast 

 with the present distribution of their descendants. The 

 contrast between the continents was not so great as in 

 earlier times, and the whole Northern Hemisphere was 

 clothed with forests much like those that survive today in 

 southeastern Asia and southeastern North America. Spe- 

 cies of magnolia, sequoia, walnut, and sassafras were then 

 native in Europe, and during early Cenozoic time the nipa 

 palm, the date, the cinnamon, and the bread fruit tree 

 lingered in our Gulf States. 



Gradually these floras become more modern; herbaceous 

 plants — those having no persistent woody stem — multiplied, 

 and then came another change of climate, during the epoch 

 known to geologists as the Pleistocene. Because of the 

 widespread glaciation which gives this epoch a distinctive 

 place in geological chronology, it is often called the Ice Age 

 or the glacial epoch, although a similar period of climatic 

 rigor, already mentioned, occurred in Permian time, and 

 evidence of other glacial epochs in early Paleozoic and pre- 

 Paleozoic time has been discovered. Pleistocene glaciation 

 was contemporaneous with the evolution of the human stock 

 and exercised a profoundly modifying influence on the 

 noble races of mammals and forest trees of the Northern 

 Hemisphere. It also modified greatly the topography, pro- 



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