Antiquity of Man

Galley Hill Man and the Antiquity of Man of the Modern Type.—In 1888 there was found in the middle or Chellean deposit of the 1 oo ft. terrace of the Thames valley a human skeleton amidst circumstances which led highly skilled geologists to infer that it had been naturally entombed when the terrace was being laid down. The site of discovery was near the Schoolhouse of Galley Hill and hence the skeleton became known by that name. If the skeleton was as old as the deposit in which it lay then men of the modern type had a great antiquity, for in no important respect did Galley Hill man differ from modern man. Discoveries of a similar import were made in terrace deposits at Clichy, Paris, in 1868. The evidence which has accumulated since these skeletons were unearthed make it increasingly difficult to accept the geological age attributed to them. The most reliable evidence now at our disposal leads us to believe that Neanthropic or modern man made his first appearance in Europe late in the Pleistocene period. Until we trace him to the part of the earth from whence he came and discover the transitional stages of his evolution in situ, we cannot frame any precise estimate of the antiquity of our own type. Such discoveries of fossil man as have been made lead us to infer that early Pleistocene times, so far as concerns our direct ancestry, was a period of rapid evolutionary change ; it was then that our brain underwent its latest unfolding and the grosser marks of the ape were shed from our frames. When we consider the very diverse forms into which Neanthropic man is now divided—Australoid, Negroid, Mongoloid and Caucasoid— it is clear we must postulate a considerable period for the differ entiation of a common ancestral stock into modern races—one which must cover the whole of the Pleistocene period at least. The faculty of speech must be of ancient origin—or how otherwise can we explain the extraordinary diversity and number of languages— extinct and living? The conquests which man has won over nature also bespeak a long past for him.

Difficulties Which Surround the Problem of Man's Antiquity.—Are we justified in giving the name of man to the beings which shaped the crude stone tools found in deposits of the Pliocene period? At what evolutionary point are we to say that the Rubicon which separates ape from man has been passed? Until we have fixed such a point we cannot discuss the antiquity of man with any measure of precision. Let us take a concrete instance. Are we to regard Pithecanthropus as man or as ape? The answer is that he was human because of the following reasons. In point of size and conformation, his brain attained almost the lowest limit of modern or Neanthropic man; his posture and mode of progression were human; his hands and arms were freed from locomotion ; his teeth fall within range of human variation. Pithe canthropus represents one of the dawn forms of humanity, and with his discovery it became possible to affirm that man's antiquity could be carried back with certainty to the close of the Pliocene period. It is not unlikely that higher forms than Pithecanthropus were evolved before the end of the Pliocene period ; the stage reached by Piltdown man early in the Pleistocene period supports such an inference. A consideration of all the evidence leads us to

expect that the fossil remains of emerging primitive man have to be sought for in strata of the Pliocene period, and those of emerg ing Neanthropic man in deposits of the Pleistocene.

Indirect Evidence of Man's Antiquity.

The evidence so far considered has had a direct and positive bearing on man's an tiquity; by the discovery of fossil remains and stone implements man has been traced through the Pleistocene into the Pliocene period of the earth's history. We have now to consider a line of evidence which has an indirect but very important bearing on the date of man's origin. Students of modern culture are well aware that a certain stage of knowledge has to be reached before a par ticular invention becomes possible. The invention of the aeroplane early in the 2oth century was conditioned by the evolution of the internal combustion engine in the latter part of the 19th century; that, in turn, only became possible when a host of discoveries had been made during the length of the 19th century. The same line of evidence applies to living types. Man's body and brain became possible only after the order of primates had undergone many and profound evolutionary changes. The full anthropoid stage had to be attained before a human form became possible. We have direct evidence of the existence of great anthropoid apes in Europe and in Asia during the long Pliocene period ; in the same continents we have traced them, by their fossil remains, far into the long geological period which preceded the Pliocene—the Miocene. The great anthropoidal type seems to have come into existence first during Miocene times, for we have found no trace of them as yet in the deposits of the still older period—the Oligocene. The meagre fossil remains of primates, so far discovered in strata of the Oligocene period indicate the existence of very generalized, small apes, one of which may well represent the ancestor of the gibbon—the smallest and most monkey-like of living anthropoids. It is useless to go beyond the Oligocene in search of a separate ancestry for mankind ; not even the small anthropoid had come into existence in pre-Oligocene times. Thus a survey of our knowledge of the evolution of the higher primates—imperfect as that knowledge still is—leads us to the conclusion that the dif ferentiation of the stem which culminated in modern man, cannot have commenced until the Miocene period was reached.

The oldest trace of a small anthropoid so far discovered comes from strata of the Fayum, Egypt, laid down in the earlier phase of the Oligocene period. The half of a lower jaw with its teeth is all that has been found of this small anthropoid which was described by Von Schlosser in 1911. He named it Propliopith ecus, and regarded it as an ancestral form of gibbon (W. K. Gregory, The Evolution of the Human Dentition, 1922).