CHAPTER* VI 



THE EVOLUTION OF MAN: PALAEONTOLOGY^ 



Richard Swann Lull 



ORIGIN OF PRIMATES 



Stock. — There is but little doubt that two important orders of 

 modern mammals, the Carnivora and the Primates, had a common 

 origin, diverging mainly along lines determined by a dietary contrast, 

 as the former have become more strictly flesh-eating or predaceous, 

 the latter largely fruit-eating and as a consequence more completely 

 arboreal. Back of each group lie as annectant forms the Insectivora, 

 not perhaps such as are alive to-day, as all these are highly specialized 

 along diverse lines, but generalized insectivores possessing, because 

 of their primitiveness, a wider range of potential adaptation. Mat- 

 thew is ''disposed to think of these, our distant ancestors, at the dawn 

 of the Tertiary, as a sort of hybrid between a lemur and a mongoose, 

 rather catholic in their tastes, living among and partly in the trees, 

 with sharp nose, bright eyes, and a shrewd little brain behind them, 

 looking out, if you will, from a perch among the branches, upon a 

 world that was to be singularly kind to them and their descendants." 

 Thus we can define the stock as a relatively large-brained arboreal 

 insectivore, of primitive but adaptable dentition, and especially of 

 progressive mentality. 



Time. — The time of primate origin must have been not later 

 than basal Eocene, as primates, clearly definable as such, are found in 

 the Lower Eocene rocks of both Europe and North America. 



Place. — The simultaneous appearance of the primate in the 

 Old World and the New gives rise to the same conclusions as to their 

 place of origin and their migrations thence as with other modernized 

 mammals. It suffices now to say that their ancestral home was 

 boreal Holarctica, probably within the limits of the present continent 

 of Asia, whence they migrated southward along the three great 

 continental radii. The impelling cause of this migration was the 

 increasing northern cold, before which the boreal limitations of the 

 tropical forests retreated, carrying with them the primates which, in 



^ From R. S. Lull, Organic Evolution (copyright 191 ?)• Used by special 

 permission of the publishers, The Macmillan Company. 



81 



