NATURE OF THE GEOLOGIC RECORD 141 



early in April, many-ceiled ones later in that month. Late in May come the 

 first vertebrates. It is the middle of July before the first land plants begin to 

 pave the way for animal life on land. Late August arrives before the first 

 land vertebrates, the amphibians, put in an appearance. The first reptiles 

 appear by the middle of September. Among these the dinosaurs dominate 

 the scene through the remainder of September, through October and much 

 of November, about seventy days. In the meantime the first birds and first 

 mammals appear. The raising of the Rocky Mountains near the end of 

 November signals the end of the great era of reptilian domination. 



As the movie runs on into December we see the mammals dominant; 

 they undergo their great evolutionary developments. Christmas arrives: 

 the movie shows us the Colorado River beginning to cut its Grand Canyon. 

 We have the vaguely uneasy realization that the year is nearing its close, 

 yet we have seen no signs of man. Day follows day until we reach the last 

 day of the year. Suddenly about noon of December 31 the movie shows 

 us the first men. During the afternoon the glaciers push southward from 

 the polar regions, and then retreat, four successive times. By suppertime 

 man is still not much in evidence. By about 1 1 o'clock in the evening varied 

 "Old Stone Age" men become quite prominent in the picture, and by 1 1 :45 

 men who make more refined stone implements and cultivate the soil ap- 

 pear. Five or six minutes before the end of the picture we see the dawn of 

 civilization. One minute and seventeen seconds before the end the Chris- 

 tian era begins. Twenty seconds before the end Columbus discovers Amer- 

 ica. Seven seconds before the end the Declaration of Independence is 

 signed. 



Many aspects of this wonderful imaginary movie are worth pondering. 

 Life has existed on earth for some eight months of the movie's year; man 

 has been here for about twelve hours of that year. The dinosaurs domi- 

 nated the movie for seventy days; man has dominated it for about half of 

 one day, so far. (Yet sometimes we look condescendingly upon the dino- 

 saurs as "unsuccessful" animals! If the movie continues into the future 

 will it show us here seventy days from now?) Man has been in existence 

 for about twelve hours of the movie, but for only about five or six minutes 

 has he had any civilization which we consider worthy the term. This is 

 sometimes a comforting thought when we become impatient with the 

 "slow" progress made by mankind in adopting various desirable reforms 

 — such as the abolition of war. In speaking of this progress as "slow" we 

 are using human lifetimes as our yardstick. Any progress made since the 

 dawn of civilization has been dazzlingly swift, measured in terms of man's 

 total existence on earth. 



