282 SCIENCE PROGRESS 



It is of course obvious that on the Darwinian theory of 

 continuous evolution there can have been no sudden appearance 

 either of the Hominidae or of true man. No doubt the theory 

 of mutation, on the other hand, implies that the stages in the 

 progression were fairly clearly marked off from each other. 

 Widely different though these rival hypotheses are, yet for the 

 purpose of the present discussion the differences are not of 

 great importance. We have to suppose that the Hominidae 

 and the Simiidae have originated from a common ancestor, 

 which closely resembled both families in its anatomy. The 

 much-discussed common ancestor was certainly biologically 

 near both to man and to the chimpanzee, though not necessarily 

 geologically near. Indeed, the creature in question would pro- 

 babty have been correctly included in the Simiidae — which is 

 not to say, of course, that any known member of the Simiidae, 

 fossil or otherwise, is ancestral to man. 



Now it follows from this that the presence of Simiidae in any 

 period implies the possible existence of primitive Hominidae 

 slightly later. I say advisedly " slightly later." The differences 

 between the Simiidae and the Hominidae are altogether trivial, 

 compared with the vast range of mammalian structure. Hence, 

 in terms of geological time, Hominidae may have appeared very 

 soon after the higher apes, even if the Darwinian theory be 

 true. Whilst if the mutation theory be correct, the interval 

 might be even shorter. For instance, a quarter or a third of 

 the Pliocene would appear to be sufficient interval, whatever be 

 the true theory of evolution. 



As already stated, anthropologists differ very widely on the 

 subject of human antiquity. The more cautious school give 

 true man only a small fraction of the Pleistocene, limit them- 

 selves to paleolithic implements (ranging over about the latter 

 two-thirds of the Pleistocene), and the most they will concede 

 is that humanoid beings may possibly have existed as early as 

 the Late Pliocene. The extreme school, including Keith, Reid 

 Moir, Rutot, and others, trace H. sapiens far back into the 

 Pleistocene, discover Pliocene and Miocene eoliths, and place 

 the origin of the human tribe in the Miocene or even in the 

 Oligocene. Rutot believes in Oligocene eoliths, and Keith 1 

 recently stated that the Javan ape-man was a type which 



1 Bedrock, January 1914. 



