Presentation on theme: "Early Man Sean Pitman, MD March 2006 www.DetectingDesign.com."— Presentation transcript:
Early Man Sean Pitman, MD March 2006
Piltdown Man Eanthropus dawsoni or "dawn man Discovered by Charles Dawson in 1912 (an ape-like mandible with human-like teeth and a human-like piece of skull) In 1953 Kenneth Oakley, Joseph Weiner and Wilfred Le Gros Clark exposed the fact that Piltdown Man was a hoax Interesting because this rather obvious hoax was accepted by the scientific community as real evidence of human-ape ancestry for over 40 years
Nebraska Man Hesperopithecus haroldcookii Mr. Harold Cook discovered one tooth in 1922 in the Pliocene deposits of Nebraska An attempt was made to use Nebraska Man as evidence in Scopes Monkey Trial Drawing published in Illustrated London News, 1922
Since William Jennings Bryan, former Secretary of State and a special prosecutor in the Scopes case, 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. Its 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. – Osborn Osborn himself commented on Forestier's drawing by saying: –Such a drawing or 'reconstruction' would doubtless be only a figment of the imagination, of no scientific value, and undoubtedly inaccurate. - Osborn
Little did Osborn know Just how inaccurate this drawing was Turned out to be a tooth from an extinct type of pig (peccary) –I wonder how the history would remember the Scopes trial if this little bit of information had become available during the trial?
Java Man Pithecanthropus erectus Found by Eugene Dubois between 1891 and 1892 Association of a human- like femur with a very large gibbon-like skullcap, found 12 meters apart The skull has a deep suture between the low vault and the upper edge of the orbits. Such a suture is found only in apes, not in man. Thus the skull must belong to an ape. In my opinion this creature was an animal, a giant gibbon in fact. The thigh bone has not the slightest connection with the skull. - Dr Rudolph Virchow, Director of the Berlin Society for Anthropology and founder of the science of pathology
While in Sumatra, Dubois heard about a skull found on the nearby island of Java, which he secured along with another similar skull at the same location These skulls were too human looking Then, in 1891, he found a molar tooth along the Solo River and later another molar and an ape- like skullcap The following year he found a human femur some yards from where he found the skullcap After consulting with Haeckel, Dubois declared the whole collection to belong to one and the same creature, stating that it was admirably suited to the role of missing link.
Leg bone is now accepted as being modern human Skullcap is still debated to be either from a giant gibbon-like creature or hominid ancestor Either way, the association of the skullcap with the femur was never justified – as originally explained by Virchow It was in recognition of this fact that the restoration of Java Man, paid for by Ernst Haeckel, was removed from the Leiden Museum to its basement in the mid 1980s. The exhibit of Java Man was also removed from public display in the American Museum of Natural History.
Getting it in the Right Ballpark Sort of...
Evolutionary Sequence from ape to human
Ramapithecus lufengensis In 1932 Louis Leaky discovered a fragmented maxilla and some teeth in southwest Kenya Assembled to form a parabolic shape similar to the human condition Presented as the first branch of ape to evolve into humans 12 to 14 million years ago
Noted scientist Dr. Elwyn Simons stated confidently [regarding Ramapithecus], –The pathway can now be traced with little fear of contradiction from generalized hominids -- to the genus Homo. The 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.
Then, a little problem surfaced for Ramapithecus (same year: 1977) A full jaw (mandible) was discovered This jaw bone was U-shaped, not parabolically shaped Zilman and Lowenstein attempt to explain the reason for the earlier thinking of most of the worlds most prominent paleoanthropologists: –Ramapithecus walking upright has been reconstructed from only jaws and teeth. In 1961 an ancestral human was badly wanted. The prince's ape latched onto 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.
A group of creatures once thought to be our oldest ancestors may have been firmly bumped out of the human family tree. Many paleontologists have maintained that Ramamorphs are our oldest known ancestors. These conclusions were drawn from little more than a few jawbones and some teeth. Truthfully, it appears to be nothing more than an orangutan ancestor. - David Pilbeam, Science, 1982
Australopithecus Australopithecus means "southern ape" – found in S. Africa Tuang Child – Raymond Dart, 1924 –Dart thought teeth human-like –Most not convinced – skull of a young 3- year-old chimp Later Dart and Broom found other Australopithecines at Kromdraii, Swartkrans and Makapansgat Two parallel lines of development, one being a small gracile (slender) type and the other a larger robust type –africanus and robustus (now thought to be female and male forms)
Anatomist Dr. Charles Oxnard of the University of Chicago claimed in a paper published in a 1975 edition of Nature 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)
However, many evolutionists, such as those that frequent Talk.Origins, argue that, "Howell et al. (1978) criticized this conclusion [of Charles Oxnard] on a number of grounds. Oxnard's results were based on measurements of a few skeletal bones which were usually fragmentary and often poorly preserved. The measurements did not describe the complex shape of some bones, and did not distinguish between aspects which are important for understanding locomotion from those which were not. Finally, there is 'an overwhelming body of evidence', based on the work of nearly 30 scientists, which contradicts Oxnard's work. These studies used a variety of techniques, including those used by Oxnard, and were based on many different body parts and joint complexes. They overwhelmingly indicate that australopithecines resemble humans more closely than the living apes."Talk.Origins Compare this statement with Spoors work on hominid semicircular canals
Australopithecus afarensis "LUCY" Discovered in 1974 by Donald Johanson Angle of knee joint matched that of humans = obviously walked upright The joint angle also matched that of tree climbing apes Also had curved toes bones, high arm to leg length ratio, and many other features identical to tree climbing apes Was Lucy just a tree climbing ape or did she walk upright?
Stern and Susman detail many features consistent with tree-climbing apes for A. afarensis Yet, they believe that A. afarensis spent much time running around on two legs? Why? The most significant features for bipedalism include shortened iliac blades, lumbar curve, knees approaching midline, distal articular surface of tibia nearly perpendicular to the shaft, robust metatarsal I with expanded head, convergent hallux (big toe), and proximal foot phalanges with dorsally oriented proximal articular surfaces. (McHenry 1994)
Interpreting the Same Things in Different Ways The perpendicular tibia, lumbar curve, and angled knee joints that are "approaching midline" are seen in modern tree-climbing monkeys The "robust" first metatarsal with an expanded head is also consistent with Stern and Susman's comment that the hand bones (and reasonably the foot bones as well), "have large heads and bases relative to their parallel sided and somewhat curved shafts, an overall pattern shared by chimpanzees" and that this, "might be interpreted as evidence of developed grasping capabilities to be used in suspensory behavior." This might especially be true if the first digit was favored by Lucy to carry most of her body weight during suspension.
Nature, 2000: Lucy was in fact a Knuckle Walker Richmond and Strait, identified four skeletal features of the distal radius of living knuckle- walking apes, chimps and gorillas with similar features found on Lucy as well as on another australopithecine "A UPGMA clustering diagram … illustrates the similarity between the radii of A. anamensis and A. afarensis and those of the knuckle-walking African apes, indicating that these hominids retain the derived wrist morphology of knuckle-walkers." Richmond, B.G. and Strait, D.S., Evidence that humans evolved from a knuckle-walking ancestor, Nature 404(6776): , 2000
3.6 million year old footprints with modern human features, adult and child Happen to be about as old as Lucy How can Lucy be a missing link if modern human posture and gait were already evolved?
As I kneel beside the large print and lightly touch its sole, I am filled with quiet awe. It looks perfectly modern. I thought that at three and a half million years ago their prints might be somehow different from ours, says Latimer. But they arent. The bipedal adaptation of those hominids was full-blown. - Gore, R. National Geographic, Feb 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 a 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 an ape toe – paleoanthropologist, Timothy White "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- Louis Robins of the University of North Carolina, Science News
Johanson insisted strongly that the Laetoli footprints simply would have to have been made by his A. afarensis (i.e. Lucy): 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.
Lucy is thought to be an ancestor or early form of A. africanus because of Lucy's more chimpanzee-like skull Problem: The foot bones and lower leg of A. africanus have been recently found These foot and leg bones are a lot more apelike than the hypothesized foot of Lucy Also, A. africanus does not have the knuckle- walking morphology that Lucy has Depending on what part of the body one concentrates on, one might be able to find evidence for just about any theory of locomotion that one wishes to find
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 Leakey 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 footprints left in Laetoli are virtually human.
Collard and Aiello, in an article for Nature, commented on this confusing phylogenic mess by saying: "The work by Richmond and Strait further complicates the picture: it suggests that A. afarensis retained some knuckle-walking features, whereas A. africanus did not. It is no longer a case of the skull pointing to one set of phylogenetic relationships, and the postcranial skeleton everything but the skullto another. Rather, different parts of the postcranium may not support the same phylogenetic hypothesis." Collard, M. and Aiello, L.C., From forelimbs to two legs, Nature 404(6776): , 2000
Semicircular Canals Fred Spoor, early 1990s Used CT-scanner on fossil hominids Results: The canals of Australopithecus africanus and robustus were most similar to the great apes The labyrinthine evidence is consistent with proposals that bipedalism in australopithecines was characterized by a substantial postural component [non-bipedal], and by the absence of more complex movements such as running and jumping. - Fred Spoor, Nature, 1994
Homo Habilis Handy Man – first discovered in 1959 by Mary Leakey Found with stone tools and evidence of butchered animals 1470 with larger dome-shaped skull, higher forehead, small brow ridges, and associated human- like femur and leg bones found in the same layer just a few kilometers away
Zinj Louis Leakey (Marys Husband) not impressed at first Commented that it was nothing more than a damned Australopithecine Quickly changed his mind when what appeared to be stone tools were found near the site - giving rise to the nameHomo habilis or Handy Man
Demotion Most other investigators not comfortable with such an extremely primitive beast being such a fancy toolmaker Like Australopithecus robustus, Leakey's Homo habilis had huge very unhuman molars (4X), huge temporalis muscles (for chewing), a very small brain (~400cc), and a large bony sagital crest on the top of its skull –Average adult human skull cranial capacity (~1350cc) Later, Leaky thought better of the whole idea of his Homo habilis as a tool maker and demoted him to the classification of Zinjanthropus boisei (East African Man) – Zinj for short –Known today as just another robust australopithecine
Promotion KNM-ER 1470 – to the rescue Found in 1972 near Lake Turkana, Kenya Richard Leakey's wife, Meave (a palaeontologist), assembled the fragments to make a nearly complete large skull (~800cc) minus lower jaw A human-like femur was also found a few kilometers away, but associated with the skull since they were both found within the same sedimentary layer)
Human-like Traits of 1470 Large endocranial volume (~800cc) A high forehead with a dome-shaped cranial vault relative to the fairly flat and low forehead of australopithecines and modern apes Lack of prominent brow ridges A "flat" face lacking the usual "protruding prognathous" of australopithecines As an extra - Associated femur and leg bones very similar to that of modern humans (found a few kilometers away in the same layer)
Problem – Too Human Original reconstruction started to be doubted, even by evolutionists, because it did not seem to fit with prevailing beliefs about human origins Such a modern looking skull, as the original reconstruction of KNM-ER 1470 came out, dated at an older age than many other much older looking australopithecines At odds with the prevailing paradigm KNM-ER 1470 began to evolve!
"When it [KNM-ER 1470] was first reconstructed, the face was fitted to the cranium in an almost vertical position, much like the flat faces of modern humans. But recent studies of anatomical relationships show that in life the face must have jutted out considerably, creating an ape-like aspect, rather like the faces of Australopithecus." – Bromage, New Scientist, 1992
Dr. Spoors research on semicircular canals of H. erectus, Australopithecus, and many other hominids indicates that H. habilis, "relied less on bipedal behavior than the australopithecines." And yet, H. Habilis is supposed to be more advanced than australopithecines? Does this make any sense at all?
Dating KNM-ER 1470 –Skull found under layer of ash –Skull should be older than ash –Ash sent to Cambridge in 1969 for K-Ar daing –Three different tests returned an age of ~220 million years –These dating "errors" were blamed on "extraneous argon –Over the following decade, the rocks surrounding 1470 were dated many times using various methods – with widely varying results –Finally the best or most acceptable date was placed at around 2.61 million years
Richard Leakey, June of 1973, in an interview with National Geographic: "Either we toss out the 1470 skull or we toss out all our theories of early man. It simply fits no previous models of human beginnings leaves in ruin the notion that all early fossils can be arranged in an orderly sequence of evolutionary changes."
Main problem: A date of 2.61my made 1470 contemporaneous with Australopithecus, if not older, and yet 1470, as assembled by Leakey's wife, looked quite similar to modern man So, what to do? Leakey, 1990 PBS documentary: If pressed about man's ancestry, I would have to unequivocally say that all we have is a huge question mark. To date, there has been nothing found to truthfully purport as a transitional specie to man, including Lucy, since 1470 was as old and probably older. If further pressed, I would have to state that there is more evidence to suggest an abrupt arrival of man rather than a gradual process of evolving.
Problem for Johanson Human-like 1470 at 2.61 my A. afarensis (Lucy) no longer evolutionary link –More human-like 1470 as old or older Lucy had previously been dated by several radiometric methods with varying results, finally settling on 2.9 my as the most probable age
Basil Cooke to the rescue Fossil pig teeth sequences –Constant but rapid evolution in the length of the third molar of certain pig fossils of southern Ethiopia Supposedly consistent over a wide geographic area Index pigs used to re-date 1470 to less than 2my, placing it on the desired human side of Lucy Lucy also re-dated to maker her a little older All very scientific and unbiased of course
Johanson, In his book Lucy, The Beginnings of Human Kind: –That meant turning to Basil Cooke and his pig sequences. These had already straightened out a dating puzzle at Lake Turkana and shoved Richard Leakey's 1470 H. habilis skull forward from 2.9my to less than 2.0my. Perhaps they could do it for Lucy too. But, in this case, they would be stretching her age not shrinking. Cooke came through as expected and said that his pig sequence showed that, An age of my would give a better fit than the previous 2.9my age for Lucy.
... In other words, with the hypodigms of H. habilis and H. rudolfensis assigned to it, the genus Homo is not a good genus. Thus, H. habilis and H. rudolfensis... should be removed from Homo. The obvious taxonomic alternative, which is to transfer one or both of the taxa to one of the existing early hominin genera, is not without problems, but we recommend that, for the time being, both H. habilis and H. rudolfensis should be transferred to the genus Australopithecus." - Bernard Wood and Mark Collardm, Science, April 1999 A Big Subjective Mess
The australopithecines are rapidly shrinking back to the status of peculiarly specialized apes… –Matt Cartmill, Duke; David Pilbeam, Harvard; Glynn Isaac, Harvard, American Scientist, July-August 1986, p.419
Neandertal (Neanderthal) Man (Homo neanderthalensis) Thought to have died out over 20,000 years ago. First found in 1856 in Neander Valley, Germany, by the school teacher Johann Fahlrott Dozens of skeletons have since been found In 1908, Professor Boule of The Institute of Human Paleontology in Paris declared Neanderthal an ape-man because of his low eyebrow ridges and the stooped over posture of some of the specimens
In 1950s it was found that Neanderthal man's average brain capacity was larger than modern man's by over 200 cc's. Some also claim that Neanderthal man, at least the stooped over ones, suffered from osteoarthritis Even as far back as1872, Dr. Rudolph Virchow, the father of pathology, claimed that these skeletons were nothing more than modern man with rickets and arthritis The Chicago Field Museum has since put in a newer exhibition of Neanderthal man looking more fully human Whats the latest scientific explanation? – Neanderthal man was an evolutionary dead-end
Obviously Neandertals cant really be human: –The skull is lower, broader, and elongated in contrast to the higher doming of a modern skull. –The average brain size (cranial capacity) is larger than the average modern human by almost 200 cubic centimeters. –The forehead is low, with heavy brow ridges curving over each eye. –There is a slight projection at the rear of the skull (occipital bun). –The cranial wall is thick compared to modern humans. –The facial architecture is heavy, with the mid-face and the upper jaw projecting forward (prognathism). –The nose is prominent and broad. –The frontal sinuses are expanded. –The lower jaw is large and lacks a definite chin. –The body bones are heavy and thick and the long bones somewhat curved.
Donald Johanson (discoverer of Lucy) wrote something very interesting about what Huxley did in setting up a sequence of modern skulls to link Neanderthals to modern humans: "From a collection of modern human skulls Huxley was able to select a series with features leading by insensible gradations from an average modern specimen to the Neandertal skull. In other words, it wasnt qualitatively different from present-day Homo sapiens."
What about DNA? July 11, 1997, Neanderthal mitochondrial DNA (mtDNA) successfully recovered and sequenced by Svante Pääbo et. al. (Cell) mtDNA recovered three times Conclusion: Evolutionary divergence from modern humans some 550,000 to 690,000 years ago
Max difference between human and human: –Ave. human difference: 8 ± 3.0 –Intra-Human Range: 1 – 35 differences (1999) –Ave. Human-Neandertal Difference: 25.6 ± 2.2 –Human-Neandertal Range: 20 – 34 –Ave. Human-Chimp Difference: 55.0 ± 3.0 –Human-Chimp Range: –Intra-Chimp Range: (1-81) Overlaps between humans and Neandertals A human-chimp relationship might be closer than a chimp-chimp relationship
Using Pääbos logic, one might rightly call their next-door neighbor a Neandertal
Further confusion from Pääbos article: –Wording seems to indicated Neanderthals are more closely related to chimps than are modern humans –Neanderthal mtDNA was actually farther away from chimp mtDNA
August of 2002, Gabriel Guitierrez et al., from the Universidad de Sevilla, Spain, Molecular Biology and Evolution, "A Reanalysis of the Ancient Mitochondrial DNA Sequences Recovered from Neandertal Bones: "Recent reports analyzing mitochondrial DNA sequences from Neandertal bones have claimed that Neadnertals and modern humans are different species. The phylogenetic analyses carried out in these articles did not take into account the high substitution rate variation among sites observed in the human mitochondrial D-loop region and also lack an estimation of the parameters of the nucleotide substitution model. The separate phylogenic position of Neandertal-Human and Human-Human pairwise distance distributions overlap more than what previous studies suggested. We also show that the most ancient Neandertal HVI region is the most divergent when compared with modern human sequences. However, the opposite would be expected if the sequence had not been modified since the death of the specimen. Such incongruence is discussed in the light of diagenetic modifications in ancient DNA sequences." Evolving After Death?
Guitierrez et al., went on to note that: "The main conclusion can be extracted from our analyses: the phylogenetic position of the ancient DNA sequences recovered from Neandertal bones is sensitive to the phylogenetic methods employed. It depends on the model of nucleotide substitution, the branch support method, and the set of data used.
Jonathan Marks (Yale University) declared mtDNA determined relationships to be highly biased: "Most analysis of mitochondrial DNA are so equivocal as to render a clear solution impossible, the preferred phylogeny relying critically on the choice of outgroup and clustering technique."
mtDNA as a Molecular Clock: –Recently called into question by articles in several well-known journals like Science –Clock off by as much as 20-fold –Mitochondrial Eve, once thought to be 100,000 to 200,000 years old, might now have to be revised to as young as 6,000 years old (Parsons et al)
Wishful Thinking at Fontéchevade
In 1937, Germaine Henri-Martin, a very well respected archeologist, began excavations in a cave in southwestern France called Fontéchevade and continued her work here until 1954, removing over 900 cubic meters of sediment Discovered first Frenchmen older than Neanderthals
Many layers found The topmost layers: "Aurignacian" (modern) Underneath the Aurignacian: "Mousterian" layers, laid down during the time of the Neandertals Below the Mousterian: "Tayacian" layers within which she found several human skull fragments and evidence for the living conditions of these first Frenchmen
Germaine found lots of evidence of how the first Frenchmen lived –The site is full of flint, which was interpreted as being worked into tools –Various "hearths" were also found throughout the site where the first families cooked, prepared their food, and ate –Evidence of meals, in the form of animal bones, were everywhere –Bones of the hominids themselves The evidence for a rather complete an intricate life for the earliest French people seemed rather obvious and fairly easily interpreted
The Rest of the Story In the 1970s Shannon McPherron and Harold Dibble decided to do some reinvestigation Laser mapped of thousands of stone objects and bones Everything in the cave was oriented horizontally or vertically with respect to the cave walls and there was evidence of water sorting The stone tools turned out to be no different than naturally carved stones Source of water found – an opening at the back of the cave that drained water and sediments from above
The narrator of the 2002 PBS documentary, "Neanderthals on Trial" concluded: "What made it look real to the archaeologists was an overwhelming desire to see the past in a certain way. The urge to distance ourselves from Neanderthals or to pull them closer to us is a surprisingly powerful force. Archaeologists Jean Philippe Rigaud and Jan Simek are well aware of the problem." [Jan Simek added], "I think that we're as guilty of it today, of that kind of preconceived approach to our data, as anybody has been in the history of archaeology or anthropology. It's almost inevitable that our own views of the world will be brought to bear... So it appears that Fontéchevade was an elaborate illusion and not a human habitation site at all. What made it look real to the archeologists was an overwhelming desire to see the past in a certain way "
It is also interesting to consider comments made by the journalist, Mark Davis, who investigated this story on Neanderthals for NOVA. "I spoke with many Neanderthal experts in the course of making this film, and I found them all to be intelligent, friendly, well-educated people, dedicated to the highest principles of scientific inquiry. I also got the impression that each one thought the last one I talked to was an idiot, if not an actual Neanderthal... The more people I spoke with, the more confusing it got... Listening to the archeologists and anthropologists talk about their work (and their colleagues' work), I heard the same frustrations voiced again and again: People are driven by their preconceptions. They see what they want to see. They find what they're looking for... I learned that what people see in Neanderthals often has as much to do with philosophy as it does with science. What does it mean to be human? Some definitions are broad and inclusive, others are narrow and exclusive. Scholars have been known to attack one another's views on Neanderthals as "racist" or "politically correct."... What I found most interesting in all this is that every scientist I talked to encouraged me to explore the issue of self-delusion, and no one claimed to be immune. They are all aware that the history of the field is littered with brilliant scholars who completely missed the boat because of the power of their preconceptions."
Dr. David Pilbeam, an anthropologist from Harvard:... Introductory books - or book reviews - are hardly the place to argue that perhaps generations of students of human evolution, including myself, have been flailing about in the dark: that our data base is too sparse, too slippery, for it to be able to mold our theories. Rather the theories are more statements about us and ideology than about the past. Paleoanthropology reveals more about how humans view themselves than it does about how humans came about. But that is heresy.