THE HAZARDS OF THE PAST 
bodies is an indubitable fact, and if collisions do 
happen to any, allow time enough and they must 
happen to all. That there are geologic dangers 
through the shifting and crumpling of the earth’s 
crust, every geologist knows, though probably none 
that could wipe out the whole race of man. The 
biologic dangers of the past we have outlived — 
the dangers that must have beset a single line of 
descent amid the carnival of power and the ferocity 
of the monster reptiles of Mesozoic times, and the 
wholesale extinction of species that occurred in 
different geologic periods. 
Nothing but a cosmic catastrophe, involving the 
fate of the whole earth, could now exterminate the 
human race. It is highly improbable that this will 
ever happen. The race of man will go out from a 
slow, insensible failure, through the aging of the 
planet, of the conditions of life that brought man 
here. The evolutionary process upon a cooling 
world must, after the elapse of a vast period of time, 
lose its impetus and cease. 
