[hill-tout] PHYLOGENY OF MAN 63 



our old monophyletic conception of man's descent and accept a 

 polyphyletic one and see in the Heidelberg and Neanderthal men, in 

 the 100-foot terrace men and possibly in Eoanthropus as well, types 

 of men so widely differentiated one from the other as to constitute 

 distinct species or even genera. 



If we consider for a moment the parallel development of the 

 anthropoid apes and observe their differentiation into distinct species 

 and genera, we shall see that this is really what we might expect 

 to find in the case of man. This has been Nature's method of working 

 everywhere. Why should man in his physical development have 

 proved an exception to her general rule? Assuredly he did not, and 

 we get a clearer view of man's evolutionary history by frankly ac- 

 knowledging this. 



Let us now consider the question of the status of Pithecan- 

 thropus in the genealogical tree of man. Instead of regarding him 

 as we did, and as some students seem inclined still to do, in spite of 

 all the evidence to the contrary, as a transitional form relating us 

 to the anthropoids and as representing one of the earliest stages man 

 went through on the road toward humanity; let us rather see in him, 

 as the veteran student Sergi has from his first discovery consistently 

 seen, not a specimen of humanity at all, not even a semi-human 

 forerunner of man, but rather one of the ancient anthropoids which 

 followed more closely than some of his fellows the lines of human 

 development, but which had departed too far therefrom when we 

 know him to be classed with the Hominidae. 



If we reflect for a moment with open minds we shall see that 

 Sergi's view has all the elements of high probability about it and 

 when presently we come to consider the evidence in support of it 

 we shall realise that it is the only one in the circumstances that 

 can be entertained. In the first place, it is extremely doubtful, as 

 he long ago pointed out, if a true transitional form ever exists in the 

 sense in which the term is applied to Pithecanthropus erectus. As 

 far as we can see, it is not Nature's method of working. We have 

 abundant evidence of progressive evolution on every hand, and of 

 simple, generalised stocks giving rise to collateral divergent forms; 

 but when once such forms have arisen and become more or less 

 specialised, there can be no bridging over the gap between them 

 by a so-called transitional form. No such form exists and none 

 could exist, blending the specialised characters of the now divergent 

 types, as Pithecanthropus was thought to do, except as the result 

 of a mating of the two types; and that such a thing as this took place 

 is so unlikely that few will be found to hold or advocate such a view. 



