THE ERA OF HELPLESSNESS 41 



to in the title, had by two slight structural changes 

 brought the human race into existence, and thereby 

 at the same time set in motion the process which 

 made those tremendous consequences mentioned 

 in the last paragraph, page 32, inevitable. For 

 these two structural changes forced our progenitors 

 to abandon tree life, yet forest trees were the 

 natural habitat of their ancestors; they forced 

 them to live on the surface of the ground in the 

 upright attitude, which involves modes of life, in the 

 most important essentials, utterly different from 

 those of their immediate forefathers. Panmixia 

 between them and their ancestral type was therefore 

 entirely out of the question. 



Therefore, provided only that they produced two 

 offspring of opposite sex, which survived them, it is 

 quite thinkable that one male and one female may 

 have been the sole adult representatives, of our race 

 in every one of many generations. Even so scanty 

 a remnant as that would have been sufficient for the 

 steady improvement of all peculiarly human char- 

 acteristics. 



If the reader bears these facts and inferences in 

 mind, then it will not be difficult in later arguments 

 to reconcile the conclusion that the growth of the 

 human intelligence was the sole means which saved 

 our race from extermination, with that other seem- 

 ingly contradictory deduction that this growth, 

 under the determining influence of natural selection, 

 by which the fittest only survive, was largely brought 



