Figure 1.9 ► The "Out of Africa" hypothesis, with some key fossil specimens representing distinct hominin species. Note that all end in extinction and that only the later Omo African hominin populations (or populations very much like them) survive to give rise to modern H. sapiens around 200,000 years ago.
(Figure 1.9). In Europe, however, the earliest representatives of a Neanderthal lineage were starting to adapt to the freezing conditions of an "Ice Age" northern hemisphere, while in mainland Asia, relict populations such as Homo erectus and Homo pekinensis lived on in isolation (see Stringer et al., 1984; Stringer & Andrews, 1988; Stringer, 1989; Groves, 1989; Stringer & McKie, 1997).
By 120,000 years ago, the modern humans of Africa began a second dispersal out of Africa into Europe and Asia. They eventually replaced the Neanderthal and Asian populations without much or any interbreeding. The "archaic" indigenous populations quickly succumbed to competition for the available resources by the more modern arrivals from Africa. According to a less extreme form, however, some paleoanthropologists who agree with much of the "Out of Africa" hypothesis suggest that there may have been some sexual contact between the moderns and the more primitive indigenous populations. However, given their suggested specific status (if correct) this would result in no offspring or in offspring that were unable to reproduce, though this may be a misunderstanding of the "reproductive isolation" model of species. Given the spatial and temporal overlap of Neanderthals and modern H. sapiens, as well as recent molecular studies (see Chapter 9), is it reasonable to suggest that there was little or no interaction between these "distinct" roaming groups, other than violence?
Initially, the hypothesis that modern humans originated in Africa was based on the available fossil and archaeological evidence (Bräuer, 1984, 1989). For example, while "classic" Neanderthal populations were beginning to dominate Europe around 120,000-80,000 years ago, more modern-looking people occupied parts of Africa, as represented in South Africa by fossil remains from Klasies River Mouth, Border Cave, and Die Kelders Cave; in northeast Africa by fossils from Omo-Kibish in Ethiopia; and in northwest Africa by the fossils from Jebel Irhoud in Morocco (F.H. Smith,
2002). The recent significant discoveries of modern H. sapiens from 160,000-year-old deposits in Ethiopia (T.D. White et al., 2003; Clark et al., 2003) have finally bridged the temporal gap between the more archaic and modern sapiens. As T.D. White et al. (2003:742) state:
The Herto hominids are morphologically and chronologically intermediate between archaic African fossils and later anatomically modern Late Pleistocene humans. They therefore represent the probable immediate ancestors of anatomically modern humans. Their anatomy and antiquity constitute strong evidence of modern-human emergence in Africa.
Fossil specimens currently considered as representing early H. sapiens are defined by a relatively short, high braincase and reduced supraorbital torus. Associated with this physical change within the African populations are signs of a change in tool technology. The long history of a stone hand axe technology gave way to lighter and more refined toolkits, which included sharp stone flakes for more precision cutting, wooden spear shafts with attached spear points, bone fishhooks, and other specialized tools to assist in woodworking and in butchering carcasses (see Schick & Toth, 1993; Deacon & Deacon, 1999). There is also, in the case of the Herto hominin, evidence of postmortuary cultural modification (Clark et al., 2003), similar to that observed in the Willandra Lakes people, who occupied Australia around 100,000 years later. It is suggested that two of the three crania so far discovered have evidence of cut marks on the zygomatic and parietal associated with selective defleshing (Clark et al.,
2003), though unlike the Willandra Lakes people there is no evidence of cremation.
The development of molecular biology and its application to the question of modern human origins has to some degree supported these paleonto-logical and archaeological interpretations. Cann et al. (1987) in their now-classic study, took the placentas from 147 women from numerous ethnic backgrounds and analyzed their mtDNA. They concluded that the African populations were more variable than those of other groups, suggesting that their mtDNA had evolved for a slightly longer time than that from other groups. This in turn suggested that the first modern humans originated in Africa and that all present-day humans are descendants of the original African ancestral group. Calculating that two samples would differ by 20-40 base mutations every million years suggested a divergence mutation rate of 2-4% per million years. This rate is partially based on the fact that the greatest degree of divergence in mtDNA types within modern human populations is about one-twentieth as great as human mtDNA is from the chimpanzee. Because the last common ancestor between humans and chimpanzees occurred around 5-6 million years ago, the last common ancestor of all modern humans was estimated at around 200,000 years ago (see Ruvolo, 1994; Pilbeam, 1996; Dover, 1999; Sykes, 2001; Relethford, 2001). Finally, as discussed previously, the extraction of ancient mtDNA from a number of Australian Pleistocene modern human remains (Adcock et al., 2001) has enabled us for the first time to examine and compare early modern human mtDNA, dating from between 60,000 and 8,000 years ago, with recent modern humans. It has been demonstrated that the preserved mtDNA extracted from Mungo 3 (dating to between 60,000 and 40,000 years ago) and from later specimens from Kow Swamp and Mungo (about 15,000-10,000 years ago) are all relatively similar to one another as well as to modern humans, especially when compared to the mtDNA of Neanderthals. The extracted Neanderthal mtDNA comes from specimens dated to around 35,000 years ago and is distinct not only from modern humans but also from Mungo 3; that is, the older Australian mtDNA is closer to that of modern humans than is the later Neanderthal mtDNA. This clearly supports the "Out of Africa" hypothesis. This as well as other issues discussed in this chapter will be considered in greater depth within the forthcoming chapters.
The next chapter will review the emergence of the earliest Miocene apes around 23 million years ago and finish just before the emergence of the earliest proto-humans in Africa from between 7 and 5 million years ago, which may (or may not) represent the earliest members of the human lineage. It is around 17 million years ago, we theorize, that the first hominid arose "Out of Africa." It is also from one of these early primitive hominid groups that the earliest members of our own lineage, Homo, evolved. Without them there would be no story to tell.
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Biologists are not always looking anxiously over their shoulders in case the general public should discover that evolution is all a confidence trick, though some creationist writings seem to imply that. But biologists have become a bit distressed over the past 20 years or so that the message is not getting through. In Australia, Mike Archer's probes seem to suggest that about 15% of the population would rather believe in the literal truth of the Bible than in science; in the United Kingdom and Canada, the figure is lower, perhaps 5%; but in the United States it is much, much higher — over 40%.
Very curious. Here is the world's most powerful country, with its most eminent scientists, yet nearly half of its population simply does not believe what these eminent scientists are finding out. In fact, science seems to be subject to democracy. In the United States, school boards — those who decide on the curriculum for schools in local districts — are elected by popular vote, and some members of some school boards have won election by promising that they will deny children the right to be taught about evolution. Actually, very few of them go quite that far; mostly, they push a wedge in the door by saying that fair's fair: Where "evolution science" is taught, then something called "creation science" must be taught as well. What could be more balanced than that?
Science is a process of finding out. It is not a matter for democracy. You can't vote on the truth.
Creationists write lots of books. Usually they are full of bright pictures and cartoons, and their arguments against evolution consist in the main of quoting scientists verbatim but out of context so that it looks as if the scientists are admitting some dreadful secret, that the evidence for evolution is actually pretty sparse, maybe even doctored. The books are not actually science books at all, though their adherents treat them as if they are. You can read some funny things there. For instance, there is a strange, intemperate book by one Father Patrick O'Connell called Science of Today and the Problems of Genesis, first published in 1959 and reprinted in 1993. Father O'Connell was in China during the 1930s and read the reports of the discoveries at Zhoukoudian as they came out in the newspapers. This made him, in his opinion and that of the creationists who quote him devotedly, an expert on "Peking Man." His woeful understanding of anatomy and geology and his ignorance of the process of casting (which he thought was just making models or copies) led him to accuse Franz Weidenreich (after the latter's death, of course) of falsifying the records. The tragedy that the original 1930s specimens were lost during the war, enabling him to propose a truly libelous hypothesis: that the eminent Chinese paleoanthropologist Bei Wenzhong, who had been involved in the Zhoukoudian discoveries, "may have destroyed the fossils [during the war] before the Chinese government returned to Peking in order to conceal the fact that the models did not correspond to the fossils." In 1981 a truly disgraceful book by J.W.G. Johnson, called The Crumbling Theory of Evolution, was published. Johnson had read no science at all, only other creationists. Treating O'Connell's hypothesis as if it were fact, he wrote, "That, to me, was the masterstroke. Get rid of the incriminating evidence; and let Peking Man live on as our immediate ancestor."
Creationists have let their ignorance give them free rein to accuse Eugene Dubois, the discoverer of the first Homo erectus at Trinil, of dishonesty as well. Both Malcolm Bowden's (1977) Ape-men: Fact or Fallacy? and Duane T. Gish's (1978) Evolution: the Fossils Say No! imply that, while he had been promoting his "Pithecanthropus" discovery, Dubois had all the time been hiding the fact that he had uncovered evidence that the ape-man had been contemporary with real human beings ("Dubois concealed the fact . . ."). They mean the Wajak Homo sapiens skulls — which of course had never been thought to be contemporary with Trinil at all. Needless to say, in the hands of J.W.G. Johnson, never one to avoid a barefaced lie for a good cause, this veiled implication becomes fact: "However, Dr Dubois had not told the whole truth. He had not told the most important part of the story. He did not tell that he had also found two human skulls in the same stratum as the skull-cap. To have told this would have spoiled his case because those human skulls, the Wadjak skulls, as they are called, showed that real human beings did live in Java at the same time as the supposed ape-men."
Of course, it is quite true that paleoanthropology has not been lacking in its embarrassing mistakes. One that is brought up without fail in creationist writings is Nebraska Man. A storm-in-a-teacup brewed by Osborn, who mistook a fossil peccary tooth for a primate one and described Hesperopithecus haroldcooki on it, was stirred by an overzealous artist in the Illustrated London News, who "reconstructed" a whole proto-human on that slender basis, before being finally laid to rest by Osborn himself when he realized his error — a nice example of the self-correcting nature of science, which creationists would do well to emulate.
Another creationist mainstay is the notorious Piltdown forgery, in which (in the early 20th century) parts of a human skull and an orangutan jaw were fraudulently modified to make it appear that they were one creature. Many scientists were fooled, and in 1913 the taxon Eoanthropus dawsoni was erected for the composite. Not until 1952 was the fraud uncovered, by first using fluorine content analysis and then carbon-14. The point creationists always overlook when retelling this tale is that, as more and more genuine fossils were discovered in the 1920s to 1940s, Piltdown came to look more and more anomalous. Specialists increasingly questioned whether the skull and jaw really did belong together. They also overlook that it was scientists — in creationist jargon, "evolutionists" — who exposed the fraud in the end. This very precisely illustrates the way science works; if some paleoanthropologists had been gullible, that is just human nature and has nothing to do with the study of human evolution as such.
Creationists also tend to trot out a batch of modern human remains that, they claim, are ignored or covered up by "evolutionists" because they are from very early strata and so don't fit. Actually the reason these are nowadays ignored (and appear in few modern textbooks) is not because of a cover-up but because they are rubbish. Calaveras (California) is a supposedly Miocene skull claimed by gold miners in the 1880s to have been found in gold-bearing deposits; it was in fact a notorious hoax — the creationists'
Piltdown, one might call it. The Castenedolo (Italy) skeletons and other remains were found in Pliocene marine deposits between the 1860s and 1880s; chemical and radiocarbon tests have shown them to be recent burials. The Foxhall (England) jaw, found in a sand quarry by workmen in 1855, was purchased by a pharmacist and sold to an American, Dr. Collyer, who claimed for some obscure reason that it came from the base of the Suffolk Red Crags, of Pliocene age. The Abbeville or Moulin Quignon (France) jaw was another fraud, placed in the ground by workmen, in 1863, to be found by them when the archaeologist Boucher de Perthes was watching. And so the sorry list goes on. The creationists who love to accuse paleoanthropologists of fraud (almost invariably dead paleoanthropologists, who can't sue) fall over themselves in the rush to resurrect discredited specimens as showing modern humans back in the Dark Ages, when only australopithecines cased the joint.
Oh, there are other brainstorms. There is the guy who is sure that our ancestors were bipedal and had huge globular heads from way back — we just haven't found their remains, that's all. There are the followers of Erich von Daniken, who wrote that human beings were not as bright as all that and that visitors from outer space had to come along and teach them to build pyramids. Why, they may even have tinkered a bit with our DNA to make us really truly human. Then there were Fred Hoyle and Chandra Wickramsinghe, two eminent astronomers, who maintained that there have been periodic influxes of viruses, dropping as the gentle rain from heaven, and that these invaded the DNA of earthbound organisms and caused evolutionary boosts. And sundry folk are convinced that Neanderthals, or Homo erectus, or Gigantopithecus at the very least, still roam the mountain fastnesses of the Himalayas, or the Altay, or the Pacific coast of North America, peering out at earnest souls who mount expeditions to look for them and giving them the slip. The Bigfoot seekers don't make as many millions from their efforts as did von Daniken. (Indeed, the world would be a poorer place without them.) And none of the minor brainstormers have anything like the insidious influence on people's minds as do the creationists.
Most creationists like to give the impression that the entire edifice of human evolution is based on nothing more than a handful of fragments. So Malcolm Bowden in his 1977 book (see previous) wrote that "the fossil links between man and the animals consist only of fragments of jaws, some broken skull pieces, part of a foot, etc., no complete skeleton or even a reasonable proportion of one ever having been discovered." This was crap even at the time he wrote it. But of course most creationists read only other creationists, so it is no surprise to read Unfred and Mackay in 1986 telling the world how little fossil evidence there is for australopithecines: "Australopithecus africanus, ... a nearly complete skull, several jaws, numerous teeth, portions of pelvis and fragments of long bones; and Australopithecus robustus, ... a small portion of the left side of a skull, ends of a few limb bones and a young lower jaw." Their source for this devastatingly incomplete catalogue? Bowden.
And so it goes on. The dismal catalogue of creationist ignorance, half-truths, and utter dishonesty goes on. There are a few — a very, very few — creationists who do seem to be more honest. The Hindu creationists Michael Cremo and Richard Thompson in 1993 wrote a vast tome called Forbidden Archaeology, claiming that humans are billions of years old, just as the Hindu scriptures say they are, and that there are lots of traces of them in Palaeozoic deposits that have been suppressed by orthodox archaeology and paleoanthropology. Marvin Lubenow, a mainstream Christian creationist, wrote Bones of Contention in 1992. Both books at least don't try to hide how abundant human fossils are or attempt to accuse honest scientists of fraud; but, like the rest, Cremo and Thompson too drag up long-discredited "ancient" Homo sapiens, and both of them bust a gut to fit the facts into their religiously mandated prejudices — but all creationists do that. One who certainly knows what he is doing, in anatomy at least, is Jack Cuozzo, who studied some of the original fossils of Neanderthalers; but his 1998 book, Buried Alive, is totally off the planet, proposing that Neanderthal skulls like La Ferassie and La Chapelle are the characters who lived shortly after Noah's Flood and, as we are assured by the Book of Genesis, lived to over 300 years — and that their great age explains their peculiar anatomy.
Ah, Noah's Flood. That mainstay of creationists who assume the inerrancy of the Bible. The Garden of Eden is important, but Noah's Flood explains everything. See, it explains the entire geological column — all that thickness of sediment deposited by a massive deluge in less than a year. Goodness me. Duane Gish, like Jack Cuozzo, believes that Neanderthalers and their ilk are "descendants of post-Flood man" because the deposits in which they have been found are Pleistocene, "believed to be post-Flood" (by whom? Ah yes, we forgot: by Gish). If you think that is from left-field, try this, from a creationist called Kofahl: "In fact a number of the man fossils may represent peoples which had suffered degeneration as the result of sin."
As for culture, all this Palaeolithic-Neolithic-Metal Age business must be rejected out of hand (whatever the stratigraphic evidence in archaeological excavations!), because Noah, from whom we are all to have descended, had access to "ocean-liner technology" (so said John Mackay in 1984). Peoples who today use (or until recently have been using) a stone technology have degenerated: "The current status of the races . . . is not a result of innocent people searching for improvement. It is a direct consequence of whether the ancestors of any race worshipped the living God or deliberately rejected Him. . . . [Technologically simple peoples are] spiritual degenerates in need of the gospel of the Creator Christ so they can appreciate education and the relevance of technology" (Mackay again).
It is a disgrace that people who claim to be men of God can not only write like this, but can for no cause accuse scientists of fraud and falsify the evidence to fit their own assumptions. It is an even greater disgrace that they wish to alter school curricula to teach kids this falsified fantasy as science. It is astonishing that so many ordinary people eagerly consume this pernicious rubbish. But they are innocent victims; they do not bear the burden of guilt that the purveyors do. The story of human evolution has many different models and hypotheses and takes slightly different forms in the hands of Chris
Stringer, Leslie Aiello, Gunther Brauer, Milford Wolpoff, Wu Xinzhi, Alan Thorne, Fred Grine, Ron Clarke, Fred Smith, Yoel Rak, Philip Rightmire, and dozens of other competent paleoanthropologists. Still, they all have one thing in common: They know what they are talking about, they are honest brokers, they try to dupe no one. But then, unlike the creationist rabble, they are scientists. Speaking of science . . .
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