Skull 1470 (Part 2)

THE skull that, according to Leakey, has made current theories of early man obsolete was found in August, 1972. It is becoming widely known as skull 1470, its museum accession number. An eagle-eyed member of one of Leakey's Kenyan field crews made the discovery, spotting a few scraps of bone weathering out of sandy sediment. Before the first day was over, thirty pieces had been recovered. Days of screening sediment at the spot ultimately yielded scores of fragments. Bit by bit the skull was pieced together over a period of weeks, a job complicated by the fact that the skull is not complete.

As the pieces of the skull came together, Leakey became increasingly convinced that the pieces of current theories about early man were coming apart. This conviction was strengthened by the discovery soon thereafter of fragments of another skull, perhaps that of a child, which seemed to be similar to skull 1470, and by the discovery of a broken but complete femur as well as portions of a tibia and fibula, all from the same leg. These bones were indistinguishable from their counterparts in modern man. The only problem is that it is not possible to know for sure that the leg bones belong to the same species represented by the two skulls.

To be fair to Richard Leakey, we must emphasize the fact that the claims he has made for skull 1470 certainly do not imply that he is on the way to becoming a creationist. Even less do they imply that he is about to come to the support of a literal interpretation of Genesis regarding the origin of man. Leakey believes in the evolution of man. But he is saying that the Australopithecines, so widely assumed in the discipline of anthropology to be "missing links" between man and ape, are not ancestral to man at all. He is saying a creature closer to modern man was a contemporary of the Australopithecines and as a contemporary could not have evolved from presently known Australopithecines. Leakey argues that the evolutionary emergence of man occurred earlier than previously thought. He feels that when man's precursor is found it will prove to be the common ancestor for both man and the Australopithecines.

In order to avoid distorting Leakey's position it should also be noted that he does emphasize the fact that skull 1470, although possibly belonging to the genus Homo, is not of the same species as modern man and possesses certain "primitive" features which are carry-overs from its ape ancestry. A major primitive feature, according to Leakey, would be the relatively small brain. Although said to possess a cranial capacity markedly larger than that of the Australopithecines, the 800 cubic centimeter cranial capacity of skull 1470 is still somewhat small compared to the 1350 cubic centimeter average for modern man.

The real point of interest, though, is Leakey's contention that skull 1470 probably represents an early form of true man and therefore the intermediate forms between the apes and man are still missing. Since creationist models of human origins emphasize the discontinuity between man and animals, it is possible for supporters of a creationist model of human origins to view skull 1470 as, if not a giant leap, at least a small step in the right direction.

A giant leap forward for Seventh-day Adventist interpretations of early man would be the discovery of excellently preserved fossil men that do not need extensive reconstruction and are indistinguishable from modern man in the same strata that contain the Australopithecine materials. Even better, from a Seventh-day Adventist perspective, would be the discovery of obvious antediluvian skeletons in these strata. Authenticated finds of that type have not yet been made.

How valid is Leakey's interpretation of skull 1470? The past history of claims made by paleo-anthropologists in general and by Louis Leakey, the father of Richard Leakey, in particular, should lead one to exercise a certain amount of caution. The track record is not too good. Louis Leakey's handling of his Zinjanthropus boisei find is instructive. When Leakey found Zinjanthropus in 1959 he immediately announced to the world that the "earliest man" had been found. Although Zinjanthropus was an interesting and significant find, it is clear now that it was in no way the "earliest man" but simply another version of one of the Australopithecine types already well known from earlier finds in South Africa.

The history of the Leakey tradition in Africa has been to leak dramatic announcements to the popular press before the materials announced have been reported to the scientific community and studied carefully by other interested and competent scientists. Often after the dust has settled, the initial claims seem overblown. One does have a feeling, however, in reading Richard Leakey's re ports that he is trying to be a bit more cautious. Furthermore, a number of competent and well-known scientists are cooperating with him in his research in East Africa (Richard Leakey himself has little formal training in anthropology at the graduate level). It may be unfair to stigmatize Richard Leakey's work because of the controversial nature of his father's career.

There are other points, nevertheless, that suggest the need for caution. The major problem is that it is impossible at this point to evaluate fully the significance of these finds because they have not yet been adequately described in the scientific literature. The kinds of popular reports one finds in the National Geographic are not adequate for use in careful scientific evaluation and are not intended to serve that purpose. The find has been announced in one scientific journal, the British journal Nature, but a really detailed description and analysis has not yet appeared.

The condition of skull 1470 also suggests the need for caution. The skull was crushed and incomplete and had to be reconstructed from myriads of small pieces. Since there is always room for some error in the reconstruction process, the bias of the particular scientist can also find some room for expression. It is significant that measurements of the cranial capacities of Australopithecines have varied by as much as 50 per cent when taken by different scientists. We do not know how accurate the reconstruction of skull 1470 has been.

Another factor suggesting the need for caution is the fact that the illustrations of skull 1470 in the popular press may exaggerate its modern features. The photographs of the skull that have appeared in the National Geographic seem to have been taken at an angle that enhances its modern qualities. This is particularly true of the height and shape of the forehead. The skull seems to be slightly tipped so that the forehead appears higher than it actually is. Side-view photographs published elsewhere look a bit different. ² Viewed from the side the fore head does not seem to be quite as high as it does in the pictures published in the National Geographic. Indeed, the side-view photographs show a forehead with a slope and height not much different from that of certain Australopithecine skulls of the gracile type from South Africa. ³

It must also be emphasized that the reconstructed appearance of the face given in the popular magazines is partly speculative. The appearance of such facial features as the lips, the skin, the hair, are fully speculative. However, other aspects of the reconstruction are certainly not purely speculative but are based on sound anatomical considerations and clues inherent in the bones of the skull. There is every indication that the illustrator has done an excellent job of reconstructing the general shape and appearance of the face. Nevertheless, as the National Geographic article wisely emphasizes, some aspects of the appearance of the face are inevitably at least partially speculative. The impact of the pictures is such that it is easy to overlook or forget this fact.

It is also important to emphasize the danger of relying heavily on one or two finds in building interpretations of early man. There is always the problem of variability within a species. If a future anthropologist were to dig up an African Pygmy skeleton on the one hand and one of the extremely tall members of the African Watusi tribe on the other, he might be tempted to conclude he had found two different species.

There are tremendous differences within humanity as we know it today, and there is no reason to suspect that things were any different in the past. It is dangerous, in view of these differences, to build up an interpretive picture based on one or two fossil finds. For example, one of the factors emphasized quite strongly by Leakey is that the cranial capacity of skull 1470 is greater than that of the Australopithecine skulls. But there is no denying the fact that there is dramatic variability in the cranial capacity of man today. Some individuals may have a cranial capacity of more than 2,000 cubic centimeters while others may have cranial capacities as small as 1,000 (if not smaller) and be perfectly normal and every bit as intelligent as well.

The relationship of brain size and intelligence in animals is complicated. Qualitative differences are involved as well as the relative size of the brain in relationship to body size. It follows that conclusions regarding the affinities of skull 1470 based on its cranial capacity must be viewed with caution. Certainly if future anthropologists were to excavate a skull of a modern man with a cranial capacity of over 2,000 cubic centimeters and then were to find a skull of a modern man with a cranial capacity of only 900 cubic centimeters, in the absence of evidence for the amount of variability possible in the species, they might conclude they had found two species. Or they might, if they lacked evidence for the relative ages of the skulls, conclude that the 2,000 cubic centimeter skull represented a population that evolved from more dimwitted ancestors with cranial capacities of only 900 cubic centimeters.

A final note of caution perhaps should be sounded. Since a re searcher's bias inevitably affects his perceptions of the data it should be noted that the bias of the Leakeys, father and son, has always been that true man evolved earlier than supposed by most anthropologists. Skull 1470 is sup posed to be (according to the potassium-argon radioactive method of dating) 2.6 million years old. It fits the bias of the Leakeys. There may be an unconscious motivation to interpret features of this skull in a way that makes it appear fully human.

In summation, all the cautions that creationists have urged so forcefully relative to the conclusions being drawn about the Australopithecines by anthropologists should now be directed towards conclusions being drawn by Leakey regarding skull 1470. Although it is probably to the creationist's advantage to accept Leakey's interpretation of skull 1470 (except for its age), it is only fair and in the long run the better part of wisdom to approach the interpretation of skull 1470 with the same caution exercised relative to the previous Australopithecine finds.

The Christian can afford to be cautious and patient. He does not need skull 1470 to bolster his faith. Surely Christian faith in the Biblical view of man must have a fundamental validity independent of the latest fossil find. If faith hangs by the thread of the latest fossil discovery it is probably doomed to ever slowly twist in whatever wind may be blowing. The latest fossil find is not in and tomorrow's find could change the scientific picture dramatically. Can tomorrow's find control the reality of today's faith?

It is legitimate, of course, to point to finds such as skull 1470 as possible straws in the wind; to emphasize the relatively tenuous nature of some of the evidence upon which anthropological interpretations of human origins have been based; and to illustrate this tenuousness by showing how one find, a skull 1470 perhaps, can alter those interpretations.

It is also legitimate to emphasize that some of the problems that have traditionally hampered paleoanthropology remain with the discipline, although mitigated by a growing awareness of their presence and an increasing maturity within the discipline. These include four problems in particular: (1) The problem of building hypotheses on fragmentary evidence; (2) the problem of the effect of observer bias on perceptions of the data; (3) the problem of understanding the significance and appreciating the range of variability possible within given species; and (4) the problem of reliance upon negative evidence. These problems still render the situation fluid and make anthropological interpretations of early man fragile. The same problems, however, make it unwise at the present time to claim that skull 1470 supports the creationist position. In my estimation skull 1470 can best be used to illustrate that as of now no specific anthropological model of human origins is conclusively substantiated by fossil evidence. To sum up. Has skull 1470 left in ruins the notion that all early fossils can be arranged in an orderly sequence of evolutionary change? Does it enhance the creationist position? In a word—perhaps, but it is too early to tell.