SECTIONAL TRANSACTIONS.—C. 369 
Friday, September 25. 
Discusston on The Evidence of Paleontology with regard to Evolution. 
(Sir AnTHuR Kerrn, F.R.S.; Prof. H. L. Hawkins; Prof. H. Fatr- 
FIELD Osporn; Dr. W. D. Lane; Prof. A. E. Trurman; Prof. 
H. H. Swinnerton; Prof. D. M. 8. Watson, F.R.S.) 
Sir Artour Keita, F.R.S. 
The oldest fossil remains of man so far discovered are four in number: those 
of Pithecanthropus found by Dubois in Java (1891-93) ; of Sinanthropus discovered 
in China (1926-30); of Eoanthropus found by Dawson at Piltdown, England 
(1911-13) ; of Paleanthropus, represented by a lower jaw, found near Heidelberg 
(1907). There is a general agreement that the four types of beings represented by 
these fossils must be accounted human, and that they differed in structure so 
much that they must be regarded as representing four separate genera of mankind, 
whereas all living races are regarded as members of one species. There is also a 
large measure of agreement as to the date at which these four extinct types lived, 
namely, in the oldest phase of the pleistocene period. It is true that the exact 
geological horizon from which the remains of Pithecanthropus and of Hoanthropus 
came is still a matter of debate, there being a tendency to allocate the Eoanthropic 
fossils toa late pliocene horizon and to bring those of Pithecanthropus well within the 
pleistocene. Besides these four early pleistocene forms there are two others, of later 
pleistocene date, worthy of mention because of the light they throw on the evolu- 
tion of man, namely the Neanderthal type of Europe and the Rhodesian of Africa, 
What light do these six extinct types throw on the evolution of modern races of 
mankind ? We may at once say that as the geological record now stands we cannot 
trace modern man backwards to any of these six extinct types. Indeed, two of them 
we may eliminate at once—Heidelberg man and Neanderthal man. On anatomical 
grounds alone the transmutation of the Neanderthal type into man of the modern 
type seems most improbable. So far as concerns Europe the archeological evidence 
is now definite that Neanderthal man became extinct and was replaced by men of 
the modern type. On the other hand, the resemblances of the Heidelberg teeth and 
mandible to Neanderthal teeth and mandible are such that it seems extremely probable 
that Heidelberg man was ancestral to Neanderthal man. As to Homo rhodensiensis, 
he is the only extinct type so far discovered whose crude features certainly foreshadow 
those of modern man, but to which of the living races he may stand as ancestor there 
is at present no certainty. Future finds may clear up his relationships, but on rather 
meagre evidence. [I incline to the opinion that Rhodesian man will turn out to be an 
early form of negro. 
As to the relationship of the three early pleistocene types of mankind— 
Eoanthropus, Sinanthropus and Pithecanthropus—to each other and to the living 
races of mankind, there are many speculations but no definite data to guide us. I 
am less certain than I was that none of these is in the direct lineage of modern races. 
At one time I believed that the ape-like features in the jaw and teeth of Piltdown 
man excluded him from modern man’s ancestry. The evidence obtained from the 
changes in the canine teeth and in the chin region of the jaws of other early types 
of mankind leads one to suspect that what one may call the humanisation of the chin 
and canines proceeded independently in diverse branches of evolving humanity. 
Nor do I now hold it to be impossible for the form of brow ridges found in Neanderthal 
man, Pithecanthropus and Sinanthropus to be converted, or reconverted, into the 
form now found in all modern races of mankind. The ancestral position in the lineage 
of modern races of these early pleistocene forms must be left open, to be settled by 
the discovery of mid-pleistocene representatives of humanity. 
Although none of these early pleistocene forms may be ancestral to modern mankind, 
yet they do tell us much as to the general state which humanity had attained by the 
_ end of the pliocene and the evolutionary changes which marked man’s progress during 
the pleistocene period. The skull capacities of the later pleistocene men were greater 
than those of the early pleistocene ; during the earlier half of the pleistocene period 
the human brain underwent a marked increase in size and in complexity of 
convolutionary pattern. The jaws and teeth, on the other hand, underwent 
reduction. In only one of these early pleistocene men—Pithecanthropus—have we 
1931 BB 
