THE SCIENTIFIC EVIDENCE FOR THE ORIGIN OF MAN
David N. Menton, Ph.D.
One of the most fundamental beliefs of evolutionism is that man has evolved from beasts through time, chance and natural selection. Some insist that evolutionism does not teach that man evolved from apes but
rather from “ape-like” ancestors. This argument is specious as virtually any of the presumed “hominid ancestors” of man would be classified as apes were they alive today. An ape is defined as merely a tailess monkey. The research dealing with mans evolution from the apes begins with the assumption that man did in fact evolve from the apes. No observations or interpretations are allowed to question this apriori assumption. What has been sought in paleoanthropology (the study of human and “prehuman” fossil
record) then are the transitional stages from ape-like animals to man. Transitional forms have proven as elusive here however, as between any other class of plants or animals. The missing links remain missing.
One would think that paleoanthropologists would have to begin with some idea of what sort of structural features may be assumed to prove that an ape is becoming man. Since mainly skulls are found in the fossil
record, and especially teeth, we can reasonably expect that criteria used to judge transitional forms will pertain largely to these. What we are really asking is what is a hominid? A hominid is defined as an erect-
walking primate that is either a “known” ancestor of man, a collateral relative of man or true man. Obviously man is the only known hominid.
The evidence most often sighted to show that an ape is in the process of evolving into man is the shape and cranial capacity of the skull. The average for the human is 1,350 cc for a woman and 1,500 cc for a man. The normal range is from 830cc (australian aborigines) to the largest brain ever recorded, about 2,800cc. There is virtually no known correlation between intelligence and brain size among humans in this normal range. By comparison, modern apes have a brain capacity of 500cc.
DISTINGUISHING CHARACTERISTICS OF HUMAN SKULL COMPARED TO APE
Brow ridges are small
Dome shape of skull
Eye sockets broad and spaced relatively far apart
Dental arcade – parabolic for man and U-shaped for apes
Teeth morphology, small incisors and canines compared to molars in ape
Position of the foramen magnum
Shape of jaws
Angle that canine teeth enter maxilla
Do paleoanthropologists have a consistent basis for determining if an ape-like creature really is near man or becoming man? The answer is quite simply NO! In his book LUCY, Donald Johanson said :
“It may seem ridiculous for science to have been talking about humans and prehumans and protohumans for more than a century without ever nailing down what a human was. Ridiculous or not that was the
situation. We do not have even today, an agreed-on definition of humankind, a clear set of specifications that will enable any anthropologist in the world to say quickly and with confidence this one is a human; that one isn’t”.
The destinguished British Anatomist Sir Solly Zuckerman has pointed out much the same thing in a paper titled, “Correlation of Change in the Evolution of Higher Primates” (in EVOLUTION AS A PROCESS, A.C. Hardy, and E.B. Ford, eds., 1954):
“Views on phylogeny are never more than inferences, drawn in the light of the geological time scale …. The inferences are sometimes very insecurely based because of inadequacies of the evidence.” “The lack
of accepted criteria by which to judge the hominid nature, or otherwise, of borderline features in bones makes the whole position very difficult.
Still it is not difficult to tell that a human skull is human, the problem is with the idea of an ape becomming a man. What exactly would one look for in an ape to prove that it is evolving into man, or conversely, what
does one look for in men that might indcate that they are more closely related to the apes than other men? Finally, we must not overlook the problem of the range of variation which is normal for a given primate
species or sexual dimorphism which is often quite extreme in nonhuman primates.
Before we begin our consideration of the cast of characters that have been proposed as ancestors of man, we should be familiar with certain terms that are used by paleoanthropologists to name their hominid hopefuls. The term “pithecus” means ape, “anthro” means man and “homo” means self or modern man. Thus the name “Pithecanthropus” literally means “ape man”.
PILTDOWN MAN —-Eanthropus dawsoni (dawn man)
In 1912, Charles Dawson a medical doctor and an amateur paleontologist discovered a mandible and part of a skull in a gravel pit near Piltdown England. The jaw bone was ape-like but had teeth that showed wear similar to the human pattern. The skull was very human-like. These two specimens were combined to from “Dawn man”, which was calculated to be 500,000 years old.
The whole thing turned out to be an elaborate hoax. The skull was indeed human (about 500 years old) while the jaw was that of a modern ape whose teeth had been filed to look like the human wear pattern. The success of this hoax for over 50 years in spite of the careful scrutiny of the best authorities in the world led Sir Solly Zuckerman to declare:
“–It is doubtful if there is any science at all in the search for man’s fossil ancestry”.
NEBRASKA MAN —- Hesperopithecus haroldcookii
In 1922, Henry Fairfield Osborn, then head of the American Museum of Natural History, received a tooth from a Mr. Cook who said he found it in the Pliocene deposits of Nebraska. Osborn claimed that this tooth had characteristics of man and ape and decided that it was from an ancestor of man. Other distinguished scientists supported Osborn’s view. A picture of Nebraska man and his wife were published in the Illustrated London Daily News. This tooth was used at the Scopes “Monkey” trial in 1925 as irrefutable evidence of the animal ancestry of man. Since William Jennings Bryan was himself from the state of Nebraska, Osborn chided him about Nebraska man in the press:
“the earth spoke to Bryan from his own state of Nebraska. The Hesperopithecus tooth is like the still, small voice. It’s sound is by no means easy to hear —-. This little tooth speaks volumes of truth, in that it affords evidence of mans descent from the ape”.
Other parts of the skeleton were found in 1927 when it became clear that the “still small Voice” was nothing more than the tooth of an extinct pig (peccary).
This animal was long believed to be the first branch from that line of apes which evolved into man about 14 million years ago. In an article on Ramapithecus in Scientific American (May 1977) Dr. Elwyn Simons said that:
“this extinct primate is the earliest hominid or distinctively man- like, member of man’s family tree. The finding of many new specimens of it has clarified its place in human evolution”.
Simons confidently concluded that the:
“pathway can now be traced with little fear of contradiction from generalized hominids — to the genus Homo”.
The crucial importance of Ramapithecus as an early ancestor of hominids is evident in this comment by Simons in Time magazine (Nov. 7, 1977):
“Ramapithecus is ideally structured to be an ancestor of hominids. If he isn’t we don’t have anything else that is”.
Simon’s confidence in the human or hominid ancestry of Ramapithecus is surprising in view of a study by Dr. Robert Eckhardt which appeared in an earlier issue of Scientific American (226: 94, 1972). Eckhardt had made 24 different measurements of the teeth from two species of Dryopithecus (a fossil ape) and one species of Ramapithecus. He compared the range of variation of these measurements with that of similar measurements of a population of modern chimpanzees. He found that there was greater variation in the teeth among living chimps than there was between Dryopithecus and Ramapithecus. This is significant because Ramapithecus is judged to be an early hominid primarily on the basis of its teeth. Eckhardt
“there is no compelling evidence for the existence of any distinct hominid species during this interval (pliocene 14 myo), unless the designation hominid means simply any individual; ape that happens to
have small teeth and a corresponding small face.”
Richard Leaky (American Scientist 64:174, 1976) apparently agrees with Eckhardt:
“the case for Ramapithecus as a hominid is not substantial, and the fragments of fossil material leave many questions open”.
What about the human like dental arcade of Ramapithecus? In 1961, Elwyn Simons published a reconstruction drawing of the dental arcade of Ramapithecus based on a particular maxillary fragment (YPM 13799), which purportedly showed a nearly parabolic form with the post canine teeth strongly diverging posteriorly. This reconstruction has been accepted and reproduced by numerous authors. In 1969 however, Genet-Varcin using the same maxillary fragment showed that a completely different reconstruction is possible which shows the U-shaped dental arcade typical of apes. Moreover, there are living animals with dental characteristics quite similar to Ramapithecus. A high altitude baboon living in Ethiopia (Theropithecus galada) has incisors and canines which are small relative to those of other living apes. It also has the short deep face and other man- like features of the type associated with both Ramapithecus and Australopithecus. Clearly teeth reflect habitat and diet and not necessarily evolution.
Some investigators have suggested that Ramapithecus is nothing more than a female of Dryopithecus which every one agrees was an ape. Others have pointed out that some recent specimens of ramapithecus show a clear canine gap but that this is often ignored by authors who wish to emphasize its hominid status.
Many drawings have been made of Ramapithicus walking upright but Zihlman and Lowenstein have pointed out that:
“Ramapithicus walking upright has been reconstructed from only jaws and teeth. In 1961 an ancestral human was badly wanted. The prince’s ape latched onto the position by his teeth and has been hanging on
ever since, his legitimacy sanctified by millions of textbooks and Time-Life volumes on human evolution”.
Ramapithicus may not be hanging on so well after all. In a recent issue of Science 82 (April p. 6-7) is an article titled “Humans lose an early ancestor” which states that:
“A group of creatures once thought to be our oldest ancestors may have just been firmly bumped out of the human family tree, according to Harvard University paleontologist David Pilbeam.” “Many paleontologists have maintained that ramamorphs are our oldest known, ancestors, evolving after we split away from the African apes”. “But these conclusions were drawn from little more than a few jaw bones and
some teeth”. “The heavy jaw and thickly enameled teeth resemble those of early human ancestors, says Pilbeam, but in more significant aspects, such as the shape of its palate, the closely set eye sockets that are higher than they are broad, and the shape of the jaw joint, it looks more like an orangutan ancestor.”
In his book LUCY, Donald Johanson refers to the “australopithecine mess” and indeed as we shall see it is certainly that. Australopithecus means “southern ape” because the first fossils were found in limestone
quarries of South Africa (in Taungs). In 1924 a fossil of the face, lower jaw and a natural brain cast of a juvenile ape was found in a hillock together with the remains of other animals; all showed marks of inflicted blows. The fossil was given to Dr. Raymond Dart professor of anatomy at Witwatersrand University in Johannesburg.
Dart was convinced that certain features of the Taungs skull and particularly the teeth were man-like so he concluded that it represented an intermediate between apes and man. He immediately rushed a notice to the journal Nature titled “Australopithecus; the man-ape of South Africa”. His opinions on the matter were largely scorned by the scientists of the time who considered it to be some kind of chimpanzee. The skull was soon known derisively as “Dart’s baby” but Dart and Dr. Robert Broom a physician, spent the rest of their lives trying to gain acceptance for Australopithecus.
Shortly after the discovery of the Taungs “child”, as it is known today, Dart and Broom found other Australopithecines at Kromdraii, Swartkrans and Makapansgat. The apes seemed to show two parallel lines of development one being a small “gracile”(slender) type and the other a larger “robust” type. Much controversy has existed regarding these types and some investigators, including Richard Leakey, have concluded that they represent merely male and female of the same species while others say the gracile form, which is believed to be older, evolved into the robust form. Today these animals are known as Australopithecus africanus and Australopithecus robustus respectively. The latter is clearly heavier, has
more massive jaws and a pronounced sagital crest – all typical of sexual dimorphism in male apes. The australopithecines have often been found in association with other animals such as baboons and these often show evidence of bashed in skulls. Bone tools in the form of clubs, knives and choppers were found as well as evidence of fire. It might be attractive to assume that the Australopithecines had been the hunters and butchers except that some of their skulls were broken in as well. Were they then the hunters or the hunted? An American journalist met up with Dart who convinced him that the Australopithecines were actually hunting one another. The journalist, Robert Ardrey wrote a book AFRICAN GENESIS that
popularized the view of the “killer ape”.
In 1959, Mary Leaky discovered a badly broken skull (100 pieces) in Olduvai Gorge in East Africa. When she showed it to her husband Lewis he is reported to have said “why it’s nothing but a Australopithecine”. Louis quickly got over his disappointment, however, when he found a great variety of stone tools as well as the fossilized bones of animals in the same strata. The bones of many of these animals revealed that they had been butchered and deliberately broken for their marrow. Leak ey decided on the basis of this evidence that his fossil had been the tool maker and butcher and thus called him Homo habilis or “handy man”. Most other investigators, however, were not comfortable with such an extremely primitive beast being a tool maker. Like Australopithecus robustus, Leakey’s “Homo habilis” had huge and very unhuman molars, a very small brain and a large bony sagital crest on the top of its skull. Later, Leaky thought better of the whole idea of his “Homo habilis” as a tool maker and demoted him to the classification of Zinjanthropus which means East African man.
Although Mary Leaky found Zinjanthropus, or “Zinj” as it was often called, it made Louis Leakey famous as a result of the publicity he received from the National Geographic Society through its magazine and
educational films. The National Geographic Society financed Leakey’s work and largely through their publicity of Leakey and Zinj, paleoanthropology once again became both popular and respectable after a long period of disrepute following the Piltdown hoax. Today, Zinjanthropus is considered by everyone to be just another robust australopithecine just as Lewis Leaky originally said it was.
Australopithecines are considered by many to be hominids because they are believed to have been bipedal and thus walked upright. Dart and Broom for example, had no trouble determining that their australopithecines were erect walking hominids although they had no post cranial fossils! Until
the 70s, the upright and bipedal posture was based on the position of the foramen magnum and very fragmentary finds of pelvis, limb and foot bones. Then Richard Leakey found several more nearly complete remains that threw considerable doubt on the idea of a upright posture. In Science News of
1971 (100:357) Leakey concluded that:
“the Australopithecines were long-armed short-legged knuckle-walkers, similar to existing African apes”.
Perhaps no one has studied the Australopithecines more extensively than Sir Solly Zuckerman and yet he rejects the idea that they be classified as a hominid rather than simply an ape (in EVOLUTION AS A PROCESS, 1954):
“There is, indeed, no question which the Australopithecine skull resembles when placed side by side with specimens of human and living ape skulls. It is the ape – so much so that only detailed and close scrutiny can reveal any differences between them”.
As for its putative bipedal posture, Zuckerman says:
“In short, the evidence for an erect posture, as derived from a study of the inominate bones, seems anything but certain.”
In addition the anatomist Dr. Charles Oxnard of the University of Chicago claims that:
“multivariate studies of several anatomical regions, shoulder, pelvis, ankle, foot, elbow, and hand are now available for the australopithecines, these suggest that the common view, that these fossils are similar to modern man may be incorrect. Most of the fossil fragments are in fact uniquely different from both man and man’s nearest living genetic relatives, the chimpanzee and gorilla (Nature 258:389).
Neither of these investigators, who have spent much of their professional careers studying the Australopithecines, believe that they walked upright and were bipedal. Most evolutionists now consider both Australopithecus africanus and robustus to be an evolutionary dead end and few consider them
in any way ancestral to man. We could write the Australopithecines off entirely at this time were it not for the current love affair with an Australopithecine named “Lucy”.
In 1974 while searching for the bones of early human ancestors at Hadar, a desert in northeastern Ethiopia, the American paleoanthropologist Donald Johanson and French geologist Maurice Taieb discovered a nearly half complete skeleton which they estimated to be nearly 3 myo. This diminutive female specimen was named Lucy after the Beetle’s tune “Lucy in the Sky With Diamonds”. A year later portions of 13 similar fossilized animals were found. Although Lucy’s V-shaped jaw was quite different from the others it was decided to call them all Australopithicines. In most respects the skulls were markedly more ape-like than either A. africanus or robustus so they called them A. afarensis. Johanson also decided to include some Australopithecines discovered by Mary Leaky over 1000 miles away in Laetoli in the same species. Mary Leaky objected saying Johanson’s work was “not very scientific” and Johanson responded that Mary Leaky “really shows a poor appreciation of what evolution is all about”.
Lucy is about three and one half feet tall and had a tiny brain for her size even by ape standards. In his book LUCY, THE BEGINNINGS OF HUMAN KIND, Johanson said:
“with Lucy I had no problem. She was so odd that there was no question about her not being human. She simply wasn’t. She was too little. Her brain was too small. Her jaw was the wrong shape.” Her teeth “pointed away from the human condition and back in the direction of apes” and the “jaws had some of those same primitive features”.
On the basis of the knee joint and pelvic bones, however, Johanson believes that Lucy did walk in an upright bipedal fashion. Thus he believes that Lucy is an ancestor of man as well as an ancestor of A. africanus. What is rarely mentioned, however, is the fact that the knee joint was found over a mile away from the rest of the skeleton and in strata 200 feet lower!
Johanson as we have seen is quite willing to incorporate other peoples fossils into his own classification. Not only did he incorporate Mary Leaky’s Laetoli fossils into A. afarensis over her objection, he also
claimed that A. afarensis made the remarkable human footprints she had discovered in layers of volcanic ash in Laetoli. Mary Leaky discovered a 73 foot long trail of fossilized footprints consisting of 20 prints of an individual the size and shape of a modern 10 year old human and 27 prints of a smaller person. The paleoanthropologist Timothy White who was working with Leakey at the time said:
“Make no mistake about it, they are like modern human footprints. If one were left in the sand of a California beach today, and a four-year old were asked what it was, he would instantly say that somebody had walked there. He wouldn’t be able to tell it from a hundred other prints on the beach, nor would you. The external morphology is the same. There is a well shaped modern heel with a strong arch and and
good ball of the foot in front of it. The big toe is straight in line. It doesn’t stick out to the side like a’ ape toe” (Lucy p. 250, Johanson & Edey).
Louis Robins of the University of North Carolina who analyzed the foot prints said:
“the arch is raised, the smaller individual had a higher arch than I do — the toes grip the ground like human toes. You do not see this in other animal forms”(Science News 115:196-197, 1979).
In a recent lecture in St.Louis, Mary Leaky pointed out one additional feature of her footprints that one does not often see mentioned in the literature; all of the larger foot prints of the trail have a smaller
footprint superimposed on them! Mary Leaky herself conceeded that it appears that a child was intentionally lengthening its stride to step in an elders foot prints! It shouldn’t be necessary to emphasize that this is a far more sophisticated behaviour than one expects from apes. In addition there were thousands of tracks of a wide variety of animals that are similar or identical to animals living in the area today including antelopes, hares, giraffes, rhinoceroses, hyenas, horses, pigs and two kinds of elephants. Even several birds eggs were found and many of these could be easily correlated with eggs of living species.
Mary Leaky assumes that the footprints were made by some hominid but not by Homo sapiens because the stratum in which the prints are found is estimated to be 3.5 myo. That happens to be the current presumed age of A. afarensis and thus it is that Johanson insists that they simply would have to have been made by his A. afarensis:
“the foot prints would have to be from A. afarensis. They substantiate our idea that bipedalism occurred very early, and our contention that the brain was too small to master tools”.
Mary Leaky disagrees with Johanson and his claims for A. afarensis as the maker of her footprints. Mary Leaky is not the only one who questions Johansons claims for Lucy. In a recent article in Science News 122:116 titled “Was Lucy a Climber?” two groups of scientists working independently challenged the claim that Lucy had completely abandoned the trees and walked fully upright on the ground. Anthropologist Russel Tuttle from the University of Chicago said that the Laetoli footprints that Leaky discovered in Tanzania were made by another more human species of ape-man that coexisted with A. afarensis about 3.7 million years ago and that it was this unknown hominid that is the direct ancestor to man. After a careful examination of the Laetoli prints and foot bones of the Hadar A. afarensis he concluded that the “Hadar foot is ape-like with curved toes” whereas the foot prints left in Laetoli are “virtually human”.
Susman and Stern of the State university of New York at Stony Brook have concluded that A. afarensis while capable of walking upright, spent considerable time in the trees. They base this conclusion on an
examination of Lucy,s scapula, foot and hand bones which they say show “unmistakable hallmarks of climbing”. They also believe that Lucy,s limb proportions did not allow an efficient upright gait.
Finally, to make matters even more confusing, some anthropologists claim that A. afarensis is really the same animal as A. africanus. In a recent lecture at Washington University in St. Louis (May, 1984), The
Harvard anthropologist Dr. David Pilbeam stated that A. afarensis was virtually indistinguishable from A. africanus. On the other hand, Pilbeam said that he believed that A. africanus was directly ancestral to man but conceeded that in the hominid fossil record, one organism could be “substituted for another”.
As we have pointed out, the taxon Homo habilis had an illegitimate birth with Zinjanthropus whom Louis Leaky thought was the “handy man” responsible for the stone tools with which he was found buried. After the demotion of Zinj to an Australopithecine, Louis Leakey and his coworkers reported four new fossil specimens in 1964 that they found in Olduvai Gorge. These they claimed were larger brained than australopithicines and surely deserved to be classified as Homo habilis. All were badly crushed skull and jaw fragments. In his book LUCY, Johanson said that :
“always obsessed with finding human fossils, he (Leakey) insisted that these belonged to the genus Homo and should be so named”.
Measurements of the cranial capacity of these fossil fragments were difficult if not impossible but, none the less, it was concluded that they averaged 642 ccs, 200 ccs larger than australopithecines and that was
considered enough to make them human. They also felt that their Homo habilis had human-like molars and premolars. Not everyone was equally enthusiastic about these new candidates for the “handy man” however. Wilfred LeGros Clark said:
“Homo habilis has received a good deal of publicity since his sudden appearance was announced — from the brief accounts that have been published, one is led to hope that he will disappear as rapidly as he came”(LUCY).
C. Loring Brace seems to be in agreement with this assessment of the taxon:
“Homo habilis is an empty taxon inadequately proposed and should be formally sunk”.
New life was breathed into Homo habilis by Louis Leakey’s son Richard who worked in the Lake Rudolf area in Kenya. He asked for and was given financial support by the National Geographic Society for the purpose of finding human ancestors. Leakey found numerous stone tools and 40 specimens of Australopithecus. Then in 1972 he made a discovery that was to shake paleoanthropology to its foundations. He found the tool maker that his aging father had so long sought in vain. Perhaps he found even more than he bargained for. He found several fossilized bone fragments of a skull which his wife Meave carefully assembled to make a nearly complete skull minus the lower jaw. The skull was given the unimaginative name KNMER 1470 for its registration at the Kenya National Museum in East Rudolf.
The skull capacity of 1470 was difficult to estimate because the condition of the specimen but was estimated to be 800 cc, much larger than most ape-men skulls. There were only small eyebrow ridges, no crest and a domed skull typical of a human. Indeed , it appeared to be a human skull. Professor A. Cave an anatomist who was the first to demonstrate that Neanderthal man was a Homo sapiens examined 1470 in London and concluded that: “as far as I can see, typically human”. In addition, Leaky fund two complete femurs, a part of a third femur and parts of a tibia and fibula near the skull which he said: “cannot be readily distinguished form Homo sapiens”.
THE “ABSOLUTE” DATING OF 1470
How old is 1470? In July 1969 samples of KBS tuff from just above the stratum in which 1470 would be found, had been sent to Cambridge for potassium argon dating. Three tests gave average dates of 220 myo (million years old)+ or – 7my! This was considered unacceptable for this strata given its fossil content and so “extraneous argon” was blamed. Less calcified samples were sought out and tested which gave dates of 2.37 and 3.02 myo which were considered “encouraging”. Further tests were run giving dates from 2.25-4.62 myo. An age of 2.61 myo was put forward as “the best and most acceptable estimate” (Fitch & Miller, 1970, Nature 226:226-228).
Since 1470 came from just below the KBS tuff containing layer, it was decided that it was 2.9 myo. An essentially human skull 2.9 myo! In National Geographic Magazine in June of 1973 Richard Leakey said:
“Either we toss out this skull or we toss out our theories of early man”. “It simply fits no previous models of human beginnings”. “1470 leaves in ruins the notion that all early fossils can be arranged in an orderly sequence of evolutionary change”.
The problem was that 1470 was clearly contemporary with Australopithecus, if not older, and yet looked much like modern man! This absolutely unseated the Australopithecines as the an