Until about 150 years ago, the subject of human origins was almost exclusively the domain of religion. \u00a0Revelation from the gods passed down through cultural tradition told man how he came to be and about his place in the Universe.\u00a0 Since the time of Darwin, however, material from the natural world itself has been discovered that allows the sciences to address the topic as well.\u00a0 Over the past forty years, intensive field work in Africa as well as striking advances in biochemistry have fostered a virtual explosion of new data which now must be incorporated into our models about origins.<\/p>\n
Integrating a multidisciplinary database into a coherent, unified model is a difficult task. This becomes especially challenging when the issue involves our own origin, since here we cannot be neutral observers.\u00a0 The meaning and value which we assign to life are linked to the origins model we espouse. \u00a0Since our significance depends on our pedigree, those who desire there to be no supreme authority over their lives will favor a different origins model than those who seek to glorify their divine Creator with their lives.<\/p>\n
Unfortunately, most of the contact which nonspecialists have with human origins\u00a0comes through the mass media, where a secular-humanistic bias seems to pervade the\u00a0scientific content.[2] For the person who seeks to integrate this data with conservative\u00a0Christian theology, it is difficult to judge from these sources which new discoveries are important and need to be incorporated into the synthesis, and which are but the artifacts of an overly zealous grant proposal or hidden personal agenda.<\/p>\n
Because it touches closest to home, the controversy surrounding the creation \/ evolution debate becomes noisiest when the question of human origins is broached. Certainly if macroevolution[3] only concerned itself with bacteria, fish and rodents, its discussion would take place in the footnotes of biology journals; but since it ventures to offer a scientific opinion about who we are and what was involved in the process of getting us here, it commands the attention of society at large.<\/p>\n
This occurs because the meaning and value that we assign to life are linked to our models for its origin:\u00a0 For example, some argue that we evolved by a meaningless collision of molecules and have no more significance than insects who hatch, eat, copulate and die; while others hold that we are a unique special creation formed to glorify God. Because we connect our significance with our pedigree, the following review of the physical data on human origins will include some consideration of its metaphysical fallout.<\/p>\n
The goal of this article is to provide a neutral overview of some of the current data and issues in the human origins debate. Without getting buried by details, we will attempt to give the nonspecialist some feeling for the background to key scientific findings that bear on a conservative Christian reading of Genesis.\u00a0 After providing some historical background and outlining the relevant fossil and artifact evidence, we will consider some criticisms of this data.\u00a0 We will then review recent biochemical research and its contributions to this issue. \u00a0Since space does not permit us to construct a fully integrated biblical-scientific model from the data, we will focus the discussion on only one apparent clash between the biblical and scientific models, that regarding the\u00a0special creation of the first man. \u00a0Our proposed resolution will serve as an example of the integrative tension and challenges that are present in this field today.<\/p>\n
- \n
- Historical Perspective.<\/li>\n<\/ol>\n
\u00a0The first major treatises to argue for human origins from a solely naturalistic outlook were T. H. Huxley’s Man’s Place in Nature <\/em>(1863) and Charles Darwin’s The Descent of Man <\/em>(1871).\u00a0 Although Neandertal[4] fossils had been recovered in Europe starting in 1856, they were considered to be irrelevant to the discussion because at that time their unique features were viewed as racial variation, not as non- or pre-human differences of evolutionary importance.[5] Thus Huxley\u2019s and Darwin’s arguments hinged on man’s anatomical homology with modern apes and lower primates, not on any fossil\u00a0data.<\/p>\n
The quest for fossil evidence of a common ancestor for apes and man (popularly known as the \u201cmissing link\u201d) was taken up by Eug\u00e8ne Dubois, a French anatomist who was inspired by the works of Ernst Haeckel.\u00a0 Haeckel, a leading German zoologist in\u00a0the 1880’s and a strong proponent of macroevolution, proposed that the remains of\u00a0“Ape-like Men” (to which he assigned the name Pithecanthropus<\/em>) might be found on the continent of Lemuria [an ancient land mass proposed by nineteenth-century geologists that was believed to have sunk beneath the Indian Ocean].\u00a0 Dubois took a medical position with the Dutch East India Army stationed in Java (then a colony of Holland) in order to be as close to the hypothetical homeland of the missing link as possible and proceeded to excavate in the fossil beds there.<\/p>\n
After several years of work, Dubois had collected a primitive skull cap, tooth, femur (thigh bone), and several other bone fragments.\u00a0 The small brain size evidenced by the skull cap coupled with the modern appearance of the femur led him to the\u00a0conclusion that he had found a transitional ape-like man that could walk upright; hence\u00a0in 1893 he named his find Pithecanthropus erectus<\/em>.[6]<\/p>\n
Because the evidence was\u00a0fragmentary and it was not certain that all of the bones came from a single individual, Dubois’ conclusion was not well received by most of the scientific community for many years.[7]<\/p>\n
Unfortunately, Charles Dawson’s discovery of the Piltdown Man in 1913 did not\u00a0meet with the same skepticism because the find’s combination of large brain size and\u00a0ape-like jaw fit better with the preconceptions of the day.[8]<\/p>\n
Meanwhile, interest in Asia\u00a0picked up as other researchers found hominid fossils and tools in Zhoukoudian, China, and were proposing a missing link in the form of the “Peking Man.”[9]<\/p>\n
In 1925 the search for early man turned to Africa (the homeland posited by Darwin because it was the habitat of the modern ape and chimpanzee) when Raymond Dart from South Africa reported the discovery of a fossilized skull of a very primitive\u00a0young hominid, whom he named Australopithecus africanus <\/em>(“southern ape from\u00a0Africa”).[10]<\/p>\n
Informally called the “Taung baby,” its relation to mankind was rejected[11] for over two decades, until Robert Broom[12] and others recovered many more australopithecine fossils. Early twentieth-century scientific models and preconceptions about human evolution then shifted to accommodate this mounting African evidence.<\/p>\n
Louis Leakey faced the same pro-Asian bias when he began work in East Africa in 1931. \u00a0Years of effort at the now famous Olduvai Gorge in Tanzania as well as sites in Kenya yielded the Zinjanthropus boisei <\/em>or “Nutcracker Man” in 195913 and the first\u00a0Homo habilis <\/em>(“Handy Man”) fossil in 1961,[14] thus confirming the African-homeland\u00a0hypothesis in many people’s minds.<\/p>\n
Over the past forty years, the research efforts of paleoanthropologists have increased in both quantity and quality.\u00a0 It was estimated recently that we now have recovered the remains of at least 275 Neandertal individuals from more than 70 sites,[15] and the total number of known hominid fossil individuals exceeds six thousand.[16]<\/p>\n
Consequently, rather than continuing to present these results in the order of their discovery, it is much more logical to summarize the material by the age of the fossil and its features.<\/p>\n
- \n
- Generally Accepted Hominid Categories.<\/li>\n<\/ol>\n
Australopithecus afarensis<\/em><\/p>\n
The most famous example of the species Australopithecus afarensis <\/em>(\u201csouthern ape from Afar\u201d) is called “Lucy,” discovered in 1974 by Donald Johanson at the Hadar\u00a0Formation in Ethiopia.[17]<\/p>\n
Although similar specimens were found later at other east\u00a0African sites,[18] Lucy is unique because about 40% of her skeleton was recovered. Finding such a large fraction of bones from a single individual is striking, given the great\u00a0age of the fossils (dated to about 3.2 million years ago [mya]).[19][20]<\/p>\n
Standing between\u00a03.5 to 5 feet tall, A. afarensis <\/em>was thick-boned with proportionally shorter legs and longer arms than modern humans. \u00a0From skeletal remains it was postulated that this species was fully bipedal, and the later discovery at Laetoli of a 3.7 million-year-old extensive track of hominid footprints made by three bipedal individuals[21] appears to bear out this hypothesis dramatically.\u00a0 Despite her advanced pelvis and mode of walking, Lucy’s skull is very similar to a chimp’s, with a small brain (400 cc average), and large teeth.[22]<\/p>\n
Other Australopithecine <\/em>species.<\/p>\n
In the fall of 1994, the discovery of bone fragments from a more primitive\u00a0australopithecine than A. afarensis <\/em>was announced.[23]\u00a0Called A. ramidus<\/em>, these fossils\u00a0are dated at 4.4 mya (over a million years older than Lucy), and should help show how the transition was made from early arboreal monkey-like primates to walking hominids.<\/p>\n
Australopithecine hominids that appear in the record after Lucy are generally classed into at least three groups, A. africanus, A. boisei <\/em>and A. robustus<\/em>, based on their body size and cranial features. \u00a0They have larger stature than afarensis<\/em>, are also\u00a0bipedal, and differ markedly from each other in their skull structure, probably due to the\u00a0influence of diet.[24]<\/p>\n
Since only africanus <\/em>has dentition that is comparable with that found\u00a0the later homo <\/em>series, it is the only late australopithecine that some consider to be a direct ancestor to modern man.<\/p>\n
Homo habilis<\/em><\/p>\n
Homo habilis <\/em>is the name given to a group of African fossils that are believed to\u00a0have used the first primitive stone tools, called the Oldowan tradition.[25]<\/p>\n
Spanning a\u00a0time range from 2.3 to 1.5 mya, H. habilis <\/em>was clearly bipedal, thin boned, and had a larger brain size (670 cc) than A. afarensis<\/em>.\u00a0 One of the best H. habilis <\/em>specimens is the\u00a0nearly complete skull (KNM-ER-1470) found by Richard Leakey.[26]<\/p>\n
However, recent\u00a0new finds by Johanson (OH 62) suggest that H. habilis <\/em>was not significantly taller than A.\u00a0afarensis <\/em>and had a similar short leg \/ long arm structure.[27]<\/p>\n
This apparent mix of\u00a0change and stability in H. habilis <\/em>(a more human-like skull with a larger brain and smaller teeth than afarensis <\/em>is still combined with an ape-like limb structure) makes it difficult to use in gradualist evolutionary schemes as a transitional species between A. afarensis <\/em>and H. erectus. \u00a0<\/em>To remedy this problem, some suggest that this species should not be regarded as a human ancestor (i.e., a member of the genus Homo<\/em>) but\u00a0rather as a distinct evolutionary branch.[<\/em>28]<\/p>\n
Because there is considerable diversity in\u00a0features among the specimens initially included in the H. habilis <\/em>taxon, the current trend is to reassign the specimens into other better-known groups or divide them into more\u00a0finely-specified taxa.[29]\u00a0Thus Leakey\u2019s KNM-ER-1470 specimen is reclassified as Homo\u00a0<\/em>rudolfensis<\/em>.<\/p>\n
H. habilis <\/em>is the presumed occupant of the earliest known (dated to 1.8 mya) living area: This 2,400-square-foot site discovered by Mary Leakey at Olduvai Bed I contained over 4,000 artifacts and fossils. It provides direct evidence of simple windbreaks or shelters and suggests that early hominids had a nomadic hunter- gatherer lifestyle.[30]<\/p>\n
Homo erectus<\/em><\/p>\n
Homo erectus <\/em>remains cover a period from 1.8 million to 300,000 years ago and are likely the first hominids to have a global (Old World) distribution. \u00a0The most striking H. erectus <\/em>find so far is undoubtedly Richard Leakey\u2019s \u201cTurkana Boy,\u201d the nickname\u00a0given to most of the skeleton of a large adolescent that dates to 1.6 mya (KNM-WT-15000).[31]\u00a0As with habilus<\/em>, the current trend with erectus <\/em>specimens is to split them up\u00a0rather than lump them into one taxon, so the Turkana Boy now is listed as an \u201cearly<\/p>\n
African h. erectus\u201d <\/em>or h. ergaster<\/em>.\u00a0H. erectus <\/em>manufactured the more advanced flaked stone tools of the Acheulian tradition, were involved in big-game hunting, and had the\u00a0controlled use of fire. In many skeletal features they appear essentially modern.[32]<\/p>\n
The\u00a0largest differences occur in the skull, which is markedly flatter and thicker boned than modern humans. \u00a0Moreover, the brow ridge above the eyes is very pronounced, the jawbone lacks a protruding chin, and the teeth are larger than moderns.\u00a0 The brain size of H. erectus <\/em>appears to increase over time from 750 to 1,200 cc.\u00a0 Since a brain size of greater than about 800cc in a light-boned hominid places this species within the brain size range of modern man, some argue that H. erectus <\/em>is the first true modern man.[33]<\/p>\n
Others are hesitant to lump H. erectus <\/em>with modern man solely on this criteria, noting that the Acheulian toolkit is comparatively simple and remained stable for over a million years, and thus does not reflect the innovation and creativity that characterize modern human artifacts.[34]<\/p>\n
The global (old World) variation and migration patterns of the H. erectus <\/em>family have been the focus of study in recent years. \u00a0The distinctions between Asian erectus <\/em>(old popular names being the \u201cPeking\u201d and \u201cJava\u201d man) and African erectus<\/em>, combined with the very early date of some of the Asian fossils,[35] gave raise to speculations that these regional groups may have arisen from a much earlier migration than previously considered (i.e., an H. habilus <\/em>migration instead of an H. erectus <\/em>one), or that H. erectus <\/em>actually evolved in Asia and migrated into Africa, a reversal of the dominant \u201cout-of-Africa\u201d theory. However, a new erectus <\/em>find in Africa is of comparable date to the Asian fossils and shows a marked similarity to them, strengthening the single- species theory.[36]<\/p>\n
Archaic Homo sapiens<\/em><\/p>\n
Early <\/em>(or archaic<\/em>) Homo sapiens <\/em>applies to a group of fossils that share a mixture of H. erectus <\/em>and modern features [A recent trend in naming this group is to avoid the term \u201carchaic\u201d and to list them as Homo heidelbergensis <\/em>(with variation)]. \u00a0Most of these date from 300,000 to 100,000 years ago.\u00a0 In general the skeletal bones are less robust than H. erectus <\/em>while the cranial capacity is larger, but the features are blurred enough that considerable debate surrounds their classification.\u00a0 Many scholars feel that there is essentially a continuum between late H. erectus <\/em>and early Homo sapiens <\/em>both in features and culture. For example, early Homo sapiens <\/em>tools are basically of the Acheulian tradition, although some items (such as handaxes) apparently become less popular and we begin to see some refinements in toolmaking technique.[37]<\/p>\n
Archaic Homo sapiens <\/em>sites attest to a lifestyle of seasonal migration. A shore\u00a0site at Terra Amata in France dated to about 300,000 years ago yielded large oval huts with a hearth at the center, large numbers of stone tools, and possible evidence for\u00a0body decoration.[38]\u00a0However, the date and significance of this site has been\u00a0contested.[39]<\/p>\n
Neandertals<\/em><\/p>\n
Neandertals <\/em>are noted separately from archaic Homo sapiens <\/em>because of their historical fame and the ongoing debate regarding their classification.\u00a0 Their bodies, teeth and jaws are very robust by modern standards, and they share many of the cranial features found in H. erectus <\/em>(above).<\/p>\n
All of the Neandertal remains that have been recovered to date are restricted geographically to Western Europe and the Middle East.\u00a0 Their tools (called the\u00a0Mousterian culture) are more sophisticated than H. erectus<\/em>, although the evidence that\u00a0they buried their dead is limited to two examples and remains controversial.[40]<\/p>\n
Evidence\u00a0of animal trapping as an alternative to hunting or scavenging is also found. \u00a0Their first remains date back 80,000 years ago, and it appears that they were rapidly replaced by modern humans in Europe around 30,000 years ago, or that they died out before moderns immigrated into Europe.<\/p>\n
The debate surrounding Neandertals involves their relationship to modern man, because the data are ambiguous even for secular minds: \u00a0Is their culture sophisticated enough and anatomy compatible enough that they should be considered an intermediate step between H. erectus <\/em>and modern man, or do they form a separate\u00a0branch that has no recent ancestral relationship? \u00a0Did Neandertals and modern humans occupy the same geographic areas at the same time or interbreed? \u00a0The answer which secular scholars give to these questions depends heavily on the model for recent\u00a0human prehistory which they assume (see below).<\/p>\n
Anatomically modern humans<\/em><\/p>\n
Anatomically modern humans <\/em>(AMH), as the name implies, refers to hominid remains that are indistinguishable from modern man (allowing for some racial variation). They first appear in the fossil record at several sites in Africa that are dated between\u00a0125,000 to 100,000 years ago.\u00a0 The earliest remains have modern cranial features\u00a0(high forehead, smaller teeth) but use the same tools as their archaic H. sapiens\u00a0<\/em>contemporaries.[41]\u00a0Although there are some new tantalizing clues from Blombos cave in\u00a0South Africa that AMH culture had elements of art and advanced tool-making skills over\u00a070,000 years ago,[42] a distinct change occurs globally in the AMH record about 40,000 years ago, when culture that all researchers are comfortable in assigning to modern\u00a0man suddenly appears around the world.[43]<\/p>\n
We find ingenious weapons like\u00a0boomerangs, an increased use of bone for tools, evidence of higher population densities than at previous times, of long distance migration to Australia and the New World, of trade or the transport of exotic materials over considerable distances, and \u2013 most strikingly \u2013 of artistic expression (sculpture, jewelry, painting, and music).\u00a0 In artistic expression, some see the first preserved clues to the religious interests of early man. \u00a0David Lewis-Williams and Thomas Dowson propose that shamanistic\u00a0experiences explain the unusual geometric shapes seen in wall paintings that date back as far as 27,000 BC.[44]<\/p>\n
The origin of language, certainly an essential hallmark of modern man, is frustrating to evaluate since language leaves no clear trace in the archaeological record until the advent of writing (around 3,000 BC).\u00a0 Seeking secondary clues, researchers\u00a0have investigated the physiology of fossil skulls for evidence of Broca’s and Wernicke’s areas (the two principal speech centers in the brain) and for evidence of the modern human larynx structure that allows a full variety of speech sounds to be produced.\u00a0 No consensus has been reached in these studies; some argue that H. habilis <\/em>had Broca’s\u00a0area[45] and thus could speak, and others argue that even the late Neandertal did not\u00a0have our modern larynx and thus had a less efficient vocal repertoire.[46]\u00a0Still other\u00a0scholars note that just because an ancient hominid had the physical capacity for\u00a0speech does not prove that any sophisticated language was in fact used. \u00a0Working from the other direction, linguists have attempted to evaluate the rate at which modern languages develop and diverge over time so that some estimate back to a single\u00a0original tongue can be made.\u00a0 Depending on the assumptions made, the evolution time for our present language diversity appears to be between 50,000 to 100,000 years, an age that seems linked to anatomically modern humans.[47]<\/p>\n
III. Fossils: Summary and Appraisal.<\/p>\n
If one imagines the above fossil and artifact data (cranial capacity, complexity of tools, date found in the fossil record, etc.) to form a series of points on a graph, the model of human origins which one espouses will affect how one draws the line connecting the points. \u00a0Someone who believes that\u00a0God intervened in the special creation of man will place at least one discontinuity somewhere on the graph, while someone who assumes that man\u00a0shares a common ancestry with apes will arrange the data and connect the points so as to show a smooth transition from early primitive forms to late modern ones. The later scheme is the approach of secular naturalists and is shown in the figure below.<\/p>\n
- Generally Accepted Hominid Categories.<\/li>\n<\/ol>\n
![\"Origins_01_ENG\"](\"http:\/\/veritasfidei.org\/wp-content\/uploads\/2015\/01\/Origins_01_ENG.png\")
<\/a>Prior to 1979, it was generally assumed that competition for limited resources permitted only one species to be the dominant hominid population in a\u00a0region at a given time. However, fossil discoveries[48] since then showed that A. boisei <\/em>existed in Africa as a contemporary with A. africanus, <\/em>greatly weakening the argument that africanus <\/em>was ancestral to robustus<\/em>.\u00a0 In fact it appears that four or five distinct hominid species coexisted in Africa around two mya, making the evolutionary \u201ctree\u201d appear more like a bush during this period.\u00a0 The new discovery of ramidus <\/em>as the earliest known hominid replaces afarensis <\/em>at the trunk of the tree, and reopens the\u00a0debate whether afarensis <\/em>is really the last common ancestor to the australopithecine\u00a0and homo lines, as Johanson proposed but Richard Leakey doubts.[49]\u00a0The recent\u00a0discovery of K platyops<\/em>, a contemporary hominid with afarensis<\/em>, raises the possibility that the \u201cbushiness\u201d seen at two mya extends all the way down, with the result that we cannot discern a single, unambiguous ancestral lineage nor an obvious \u201clast common ancestor\u201d with the primates.<\/p>\n![\"Origins_02_ENG\"](\"http:\/\/veritasfidei.org\/wp-content\/uploads\/2015\/01\/Origins_02_ENG.png\")
<\/a>Following the early intercontinental distribution of H. erectus <\/em>around 1.5 mya, the multi- regional model <\/em>proposes that this species globally evolved into modern H. sapiens <\/em>because a\u00a0sufficient level of interbreeding throughout the dispersed population was maintained over this long time period. \u00a0Proponents for this view argue that the similarity of ancient and modern skulls found in a given location (particularly China, Australia and the\u00a0Far East) implies that the hominid population in that\u00a0geographic area has been stable for hundreds of thousands of years.[53]<\/p>\n