The Newly-Discovered Line in His Evolution
W. J. Lewis Abbott, F.G.S., F.R.A.I.
Hastings and St. Leonards Observer Feb. 1, 1913
Five years ago, in a lecture before the Eastbourne Natural History Society, I made the following remarks:"For a long period Kent has held the premier place for the production of the relics of prehistoric man: but, given only enough enthusiastic workers, and Suffolk and Sussex would soon reduce the lead."
Suffolk was the first to respond, where my friends Mr. Reid Moir, Colonel Underwood and others instituted a series of researches, which, principally by the former, led to results of quite a startling nature, and which have since been the object of discussion all over the civilised world. The first of the finds were sent to me for an opinion, together with details of the sections where they were found, and if we read them rightly, not only did glacial conditions in this country first obtain at a very much earlier period than we formerly realised, but a representative of the human family also appeared possessing sufficient intelligence to chip flints into desired forms quite early in the Pliocene period. The same gentleman also found a human skeleton at the very base of the Great Chalky Boulder clay, resting partially on the underlying Middle Glacian sands. This was a find of very great importance as the larger portion of a skeleton was recovered, and this from a deposit older than many were prepared to admit had furnished any remains of man.
At the opening lecture of the East Sussex Art Club this winter, I was able to exhibit parallel tables showing the various geological formations, and the skulls and the bones of the various races of men which had been found in them; and in another series the various forms of worked flints from each horizon. Two facts ultimately became supported: firstly, that as we descend the ladder of time the men of each successive period become more and more unlike those of the present day; and that as we went still further back we arrived at a time when men were so unlike those of the present day that we found it necessary to regard them as belonging to a different species; and that as we went yet still lower the difference became so much greater that we had to regard them as belonging to a different genus, one which, while it had a claim to the genus homo, had nearly or as great a claim to characters not found in man to-day, but only in the higher apes; and we therefore called him by a name embracing the two sets of characteristics, viz., Pithecanthropus (ape-man). We further found that at a horizon even below that on which this creature was found we had still found flints which had been worked, thus proving that so far as evidence went the anthropoids used and chipped flints before they had attained the human status.
Secondly, by another set of facts we saw evidence that mankind, like several other animals, whose phylogeny we know, had not had a monogenetic origin, i.e., they had not arisen from a single pair of even the same genus, but that they had arisen from different animals very dissimilar, and that by parallel and convergent development, and the elimination of the unfit, and the survival of the fittest, they had become what we find them to-day. The recent discoveries in Sussex have a special bearing upon both of these superbly important points.
The oldest relics of man, or a flint-using or flint-chipping creature, found in this country were first introduced to the scientific world by my friend, the late Sir Joseph Prestwich, rather less than a quarter of a century ago; they were found by Mr. B. Harrison, of Ightham. Further research showed that geological deposits of the same age occurred on the South Downs of Sussex, which also carried vestiges of the early creatures.
For a long time the relics of Palaeolithic man were found in Sussex. One of the most notable finds was that at Portslade near Brighton; here, under the direction of the late Mr. Willett, one of the men at work in that remarkable glacial deposit known as the elephant-bed had found a well-worked palaeolith. I well remember arriving at this pit just after the man had found it, and he showed me the exact spot whence he had obtained it.
Its discovery caused a great surprise at the time, but since then others have been found in the same deposit.
.... of animals with which I am acquainted there is an average relation between the length and width of these two members, both in man and, say, the chimpanzee. In a row of human jaws now before me, which I have obtained in this neighbourhood, the average is as 1.8:2.4 measuring from the front of the front teeth to the angle formed by the rising member; and the width is about .7 of the height. In 1907 a wonderful jaw was discovered at Maur, near Heidelberg, which was altogether the most pithecoid (apelike) that had ever been found. In this they were about equal, proportions about reached in the Sussex creature; a state of things obtaining in a chimpanzee jaw now before me.
If, however, we take the width of the "leg" and the "foot," it is here we shall see a greater departure, for whereas in man the narrowest part of the "leg" would come out somewhere about the width of the "foot," in the Maur creature it is very much wider, and in chimpanzee it is very much more so, and Eoanthropus comes in between, although a long way removed from man.
There is another feature about this "leg," and that is, in man it rises obliquely slanting backwards, roughly coinciding with the backward angle made for the projecting chin, but in Homo Heidelbergensis this rose practically vertical, and the chin, instead of projecting out at the bottom, receded away underneath, thus leaving him quite chinless; this it will be remembered is the great feature in chimpanzee, but it appears to have been equally shared by Eoanthropus. There is just one more feature in the jaw that so widely separates chimpanzee from man to-day, and that is the top of the "leg" in man is deeply cleft with a sweeping curve hollow; in chimpanzee this is absent; another feature shared by the Sussex connecting link.
There are numerous other features we might detail, but I trust your readers will see that if we analyse the various features of a typical human jaw, and their homologues in chimpanzees, and then the same points in Eoanthropus we shall see that they approach altogether far closer to chimpanzee than to man as we know him. Unfortunately that part of the chin which carries the canine teeth has been broken, but from the experience I have obtained in the examination of many thousands of jaws of various creatures I have obtained fossil, it is just what I should expect if the canines were essentially chimpanzoid, but not if they were of the human type. In chimpanzee there is not a thickening of the jaw so as to make it stronger, but the alveolus being larger, the jaw is weaker there, and more likely to break off at its upper margin, so that in all probability the missing teeth were essentially chimpanzoid. It has been suggested that this might not have been the case from the fact that the molars are so hard worn; but jaws in my collection do not support this counter idea, but indeed traverse it.
I should have liked to have gone into the comparative osteology of the skull, but I fear that I have already trespassed too far upon your space. In the skull the balance of measurements approach nearer the human than the ape, but that the creature had not yet attained the power of speech there can be no doubt.
With reference to the worked flints found with this creature appearing to some of a newer facies than the associated bones, I can only say that when more of these is known than now their true age will be realised, and the same may be said of the geology. When Wealden geology is re-studied on the lines above indicated, all things will show that we have at last discovered the Pliocene ancestor of at least one branch of modern man, or in the words of Professor Keith, the distinguished conservator of the Royal College of Surgeons, we have at last found what everyone had been looking for ever since Darwin propounded his immortal theory of evolution.