Impact of the Discovery of Homo Floresiensis

Impact of the Discovery of Homo Floresiensis The discovery of Homo Floresiensis has profound implications for what it means to be human; it raises questions about the uniqueness of human lineage which is the foundation of our society and our religions. The three great problems for nineteenth century ethnology and prehistory were identified by Latham in Man and his Migrations (1851) as: the unity or non-unity of the human species; its antiquity; and its geographical origin. This shortlist has formed the basis for research into human origins ever since. The ambiguity surrounding each question has been reduced to every generation’s satisfaction, then thrown open again as changes in opinion about the world and its people have led to revisions. This cyclical process has provided the spur to fieldwork and the development of new techniques of classification, analysis and dating. Latham was writing at an interesting time in scientific progress of thought, eight years before the Origin of Species was published. This was the foundation text for the biogeography of Darwin and Wallace which accounted for the distribution of life on the plant. The importance of these studies was their contribution to the scientific investigation of variation via the principle of natural selection. Individuals were the units under selection with the evolutionary results measured by their differential reproductive contribution to the next generation. The notion of a cradle for mankind, a discrete geographical centre for human origins, is an ancient idea. The Garden of Eden is the best known example. Adam and Eve might be replaced, as they were in the last century, but the idea of an ancestral homeland continued. The study of human origins now starts from a very different set of assumptions than it did when Latham penned his three questions. It is also extremely well-informed about process and patterns in the data compared to 150 years ago. The celebration of progress has fallen from the agenda. Living peoples are no longer regarded as living representatives of a past which the Western world once possessed.   But for all these apparently fundamental changes the questions on the agenda remain the same. Why should the study of human evolution be restricted, because of the search for cradles, to some continents. What it means to be human The fascination with humanity’s African origins, singular or otherwise, remains unabated. Great strides in understanding the development of modern human beings are currently being taken at the very southern tip of Africa. While much of the press attention over the past few decades has been on the scholarly debate on whether humans evolved once in Africa, universally known as the Out of Africa theory, or several times all over the world, the multiregional hypothesis, a quiet revolution has occurred centred on what it means to be human (Stringer and Gamble, 1993). Within twentieth century archaeology and palaeontology, probably since the discovery of the Lascaux Caves in France, archaeologists have continually believed that, while anatomically modern Homo sapiens evolved somewhere between 100,000-150,000 years ago, humans didnt actually develop modern behaviours and thought processes until around 50,000-40,000 years ago (Wood, 1992). This event, known in some scientific circles as the creative explosion, was announced by what researchers saw as an abrupt blossoming of symbolic thought; the ability to identify and create representations of entities. Thus, according to the creative explosion theory, H. sapiens displayed a recognisable intelligence equivalent to other hominids of the time, identifiable by the cave artwork at Lascaux. Further evidence of the initiation of modern human behaviour is alleged to include fishing, the manufacture of bone tools, and the use of decoration. Following the initial interest in Africa during the early decades of the twentieth century, the majority of archaeological research moved to Europe. The overwhelming concentration on the visible prehistory of Europe, including both cave and portative artwork, resulted in a deficit of research into human origins in Africa. The research of the past forty years has indeed been remarkable in yielding up a great many fossil and cultural remains from a broad range of African environments. After a period of relative neglect, however, increasing attention was being given to the biological and behavioural changes that led to the evolution of H. sapiens, the last major even in human evolution.   The triumph of archaeological research into the earliest prehistory of Africa was trumpeted by the archaeologist Desmond Clark in the Huxley Memorial Lecture of 1974. Titles â€Å"Africa in prehistory: peripheral or paramount?† it pointed to the overwhelming evidence from Africa for the origi n of hominids, which overthrew the previous view â€Å"that the history of Europe is emphatically the prehistory of humanity.† (Clark,1975). Eventually, evidence of an earlier flourishing of the creative mind began to appear, south of the Zambezi River, and dated to the Mesolithic, the earliest date approximating 70,000 years ago. Similar artefact assemblages known as Howiesons Poort and Still Bay had been found at sites such as the Klasies River Caves, Boomplaas, and Die Kelders Cave I in South Africa (Grine et al., 2000). These sites included sophisticated bone tools, backed blades, a careful selection of raw material for stone tools and the use of a punch technique; however, most of these were controversial in one respect or another, until the discovery of Blombos Cave. Research into the Blombos Cave assemblages have been undertaken since 1991, and artefacts identified have include sophisticated bone and stone tools, fish bones, and an abundance of used ochre (Leakey and Lewin, 1993). Ochre has no known economic function, and it is virtually universally accepted as a source of colour for ceremonial, decorative purposes. The Blombos Cave layers containing used ochre are dated 70,000 to 80,000 years BP, and, in 2004, a cluster of deliberately perforated and red-stained shell beads dating to the Mesolithic was found (Aiello and Dean, 1990). Without any obvious practical purpose these artefacts are currently interpreted as personal ornaments or jewellery, possibly belonging to the occupants of Blombos. The most persuasive interpretation of these finds, and numerous others throughout Africa, within the parameters imposed by previous and current discoveries and research, is that the growth of the human symbolic thought was a slow process that continued t hroughout the Mesolithic in Africa. Symbolism, and its deliberate representation, is a phenomenon previously unidentifiable in any extant species other than H. sapiens, despite the genetic and predominantly behavioural similarity between humans and other primates, and can therefore be interpreted as a distinctly human trait (Spencer, 1876-96). Symbolism, in all its forms, however has not always been strictly the prerogative of H. sapiens.   Many investigators of Neanderthal culture believe that H. neanderthalensis was the earliest species of hominid to ritually bury their dead, and important evidence to support this statement originates from Shanidar Cave, located in the Zagros Mountains of northern Iraq (Solecki, 1971). Between 1951 and 1960, excavations in and around the mouth of the cave were undertaken, allowing the recovery of a range of Mousterian tools, and the analysis of eight burials, relating to the remains of seven adults and one child. While four of these individuals appear to have been killed by rockfalls, four others may have been deliberately buried (Gargett, 1989). Soil samples taken around one particular burial, known as Shanidar IV, revealed the presence of pollen grains and small amounts of vegetable matter. While there was very little pollen in most of the soil samples taken around the skeleton, two samples from the burial itself contained a large number of pollen grains representing a total of 28 plant species (Leakey and Lewin, 1993). This evidence was used to support the hypothesis that more than 50,000 years ago the body was deliberately and ritualistically buried on a bed of woody branches and flowers sometime during the months of May through July, during the blooming season for the plant species. Excavations of the cave over the next decade yielded cultural data as well as skeletal remains of Middle Palaeolithic Neanderthals and Proto-Neolithic modern humans, representing two periods renowned for the scarcity of such material (Solecki, 1975). According to subsequent research, the Neanderthal and Proto-Neolithic people of Shanidar Cave potentially followed culturally-defined methods for burying their dead in a base camp, possibly increasing the groups ties to a traditional home site. They practiced both primary burial (interment of a mostly intact body shortly after death) and secondary burial (final interment of disarrayed or isolated bones or of a body that had undergone some other burial process as a first stage) (Aiello and Dean, 1990). Offerings placed in the grave included bead ornaments and assumed favoured personal objects, but no obvious symbols of rank. The variety of materials included reveals an extensive long-distance exchange trade, and the mortuary practices are comparable to those of other contemporary Near Eastern cultures (Leakey and Lewin, 1993; Solecki et al., 2004). The material culture of the cave and the surrounding Zagros area is characterized by chipped stone industry and such innovations as a variety of ground stone tools, worked bone tools and abundant personal ornaments. These suggest growing cultural richness and elaboration, a semi-sedentary lifestyle and a mixed subsistence strategy based both on wild species of plants and animals and early domesticates (Gargett, 1989). Though the interpretation of deliberate and ritualistic H. neanderthalensis burials remains contentious, with opponents suggesting the presence of flower pollen within the grave is a result not of deliberate adornment of the corpse but of the accidental deposition of flower and plant matter from burrowing rodents, until the theory of ritualistic burial is conclusively disproved it remains a highly persuasive hypothesis for cross-species traits of ‘humanity’. Although much has been made of the Neanderthals burial of their dead, their burials were less elaborate than those of anatomically modern humans. The interpretation of the Shanidar IV burials as including flowers, and therefore being a form of ritual burial, potentially evidence for the acknowledgement of a theoretical afterlife, has been questioned (Sommer, 1999). In some cases Neanderthal burials include grave goods such as bison and aurochs bones, tools, and the pigment ochre. Neanderthals performed a sophisticat ed set of tasks normally associated with humans alone. For example, they constructed complex shelters, controlled fire, and skinned animals. Particularly intriguing is a hollowed-out bear femur with four holes in the diatonic scale deliberately bored into it. Estimated to date at approximately 43,ooo up to 82,ooo years old, this ‘flute’ was found in western Slovenia in 1995 near a Mousterian Era hearth used by Neanderthals. Its significance is still a matter of dispute, however, its perfect fit to bother modern and antique diatonic scales implies the deliberate manufacturing of a musical note making device (Aiello and Dean, 1990). Music beyond the percussive, in addition to ritual and symbolism, is another previously assumed trait of H. sapiens alone, and the Slovenian flute suggests a rethink of what it means to be human may be required. Similarly, the concept of prolonged care of community individuals is a trait usually attributed to the H. sapiens species. While other species present evidence of a rudimentary form of care, the deliberate attention paid to the prolonging of life of an individual with no primitive value to a community, such as providing nutrition to an elderly community member for an extended period of time, is peculiarity associated primarily with H. sapiens. It has been previously believed that this trait, in addition to being singular to the human race, can be interpreted as a definition of what it means to be human. However, similar to the evidence presented above, there has been strongly influential evidence of ‘care in the community’ from Neanderthal societies. Following a 6 year excavation season beginning in 1899, the site of the Krapina caves, Republic of Croatia, yielded a number of osteological Neanderthal specimens. Radiographs undertaken in 1997 indicated a number of surpris ing conclusions. While the overall picture of Neanderthal health, based on the radiographs, was impressive, not all the specimens showed perfect health. Archaeologists were able to document one of the earliest benign bone tumours ever discovered and identified, and one individual may have had a surgical amputation of his hand (Leakey and Lewin, 1993). In addition, several individuals had examples of osteoarthritis ranging in severity, and it is suggested that the extended survival of these individuals following surgery or the onset of debilitating arthropathies indicates a sophisticated level of care from the healthy population. Humans are a striking anomaly in the natural world. While we are similar to other mammals in many ways, our behaviour sets us apart. Our unparalleled ability to adapt has allowed us to occupy virtually every habitat on earth using an incredible variety of tools and subsistence techniques. Our societies are larger, more complex, and more cooperative than any other mammals. Evolutionists, and scientists from other fields of study, argue that only a Darwinian theory of cultural evolution can explain these unique characteristics. The twentieth century is offering a radical interpretation of human evolution, arguing that Homo sapiens ecological dominance and singular social systems stem from a psychology uniquely adapted to create complex culture. Richerson and Boyd (2004) illustrate that culture is neither superorganic nor the handmaiden of the genes. Rather, it is essential to human adaptation, as much a part of human biology as bipedal locomotion. Drawing on work in the fields of anthropology, political science, sociology, and economics, Richerson and Boyd (2004) convincingly attest that culture and biology are inextricably linked, and their interaction yields a richer understanding of human nature. Discovery of Homo floresiensis Currently, it is widely accepted that only one hominid genus, Homo, was present in Pleistocene Asia, represented by two species, Homo erectus and Homo sapiens. Both species are characterized by greater brain size, increased body height and smaller teeth relative to the Pliocene Australopithecus genus present in Africa (Brown et al., 2004). But it was the most spectacular fossil find of a generation that has marked twentieth century studies into human evolution. The discovery that a mysterious and apparently ingenious human species may have shared the planet with our own less than 15,000 years ago captured the imagination of palaeontologists and public alike. Excavations at Liang Bua, a large limestone cave on the island of Flores in eastern Indonesia, have yielded evidence for a population of tiny hominids, sufficiently distinct anatomically to be assigned to a new species, Homo floresiensis (Morwood et al., 2004). An excavation team under the leadership of Australian and Indonesian scientists have unearthed the remains of eight human beings of relatively restricted stature and reduced brain volume, comparative to previously understood parameters for anatomically modern humans. In recognition of the combination of primitive and derived features, and their subsequently assumed status as a species distinct from Homo sapiens, the fossils were ascribed the name Homo floresiensis (Flores Man) after the island on which they were discovered. One skeleton, estimated to be that of a woman in her 30s and calculated to be approximately 18,000 years old, was only 1 metre tall, and the endocranial volume of the skeleton in question was a mere 380 cc, significant as it may be regarded as small even for a chimpanzee (Beals et al., 1984) and equal to the smallest-known australopithecines (Brown, et al., 2004). Investigations into the specimens, estimated to belong to at least eight individuals, show that H. floresiensis inhabited the cave at Liang Bua for an extended period of time ranging between 95,000 and 12,000 years ago. The common opinion of the archaeologists responsible for examining the tools and animal bones unearthed in the cave is that H. floresiensis individuals exhibited complex behaviour requiring the capacity for speech, and can therefore be regarded as social and intelligent human beings with creative ability. Stones carved and sharpened for particular purposes, and animal bones discovered in the cave, indicate t hat these people were successful hunters, capable of catching animals larger than themselves, and associated deposits contain stone artefacts and animal remains, including Komodo dragon and an endemic, dwarfed species of Stegodon. There has been some speculation that the stone tools found with it were actually made by Homo sapiens, mainly because it is hard to believe a creature with such a small brain could make such sophisticated stone tools. There is no other evidence in support of this, however, and if it were not for the small brain size, there would be no hesitation about assuming floresiensis made the tools because of the close association between the tools and the fossils. The same tools are found through the entire deposit (from 90,000 to 13,000 years ago) and, interestingly, they are not like any stone tools made by Homo erectus (Kaifu et al., 2005). The finds comprise the cranial and some post-cranial remains of one individual, as well as a premolar from another individual in older deposits. Dating by radiocarbon (C14), luminescence, uranium-series and electron spin resonance (ESR) methods indicates that H. floresiensis existed from before 38,000 years ago (kyr) until at least 18  kyr (reference). It is alleged, with much research still yet to be undertaken, that H. floresiensis originated from an early dispersal of Homo erectus, including specimens referred to as Homo ergaster and Homo georgicus, that reached Flores, and then survived on this island refuge until relatively recently. The most likely explanation for its existence on Flores is long-term isolation, with subsequent endemic dwarfing. H. floresiensis overlapped significantly in time with Homo sapiens in the region, however, interactions between the two species currently remain unknown. Importantly, H. floresiensis shows that the genus Homo is morphologically more va ried and flexible in its adaptive responses than previously thought (reference). The finds further demonstrate that H. floresiensis was not simply an aberrant or pathological individual, thereby interpretable as anomalous and inconsequential within the field of human evolution, but is representative of a long-term population that was present on the island for approximately 80,000 years. According to the dwarfism scenario, it is assumed that the H. floresiensis line descended from Homo erectus. The justification for that belief, however, is currently experiencing much debate within the archaeological academic arena, and relies on the comparison between tool assemblages uncovered from the Liang Bua cave, and thus associated with H. floresiensis, and a series of assemblages reported by Morwood in 1998, and dating to approximately 800,000 BP (Morwood et al., 1998). The similarities between these assemblages resulted in the assumption that H. floresiensis was a descendent of the manufacturer of the older collection of tools, H. erectus. H. floresiensis facial anatomy also generally resembles that of H. erectus, and, in addition, the East Asia region in which the island lies is one of the regions where H. erectus was extant for a long period. One article published in Science journal in 1996 listed evidence that H. erectus had survived on Java, an Indonesian island like Fl ores, until as recently as 27,000 years ago. (Swisher et al., 1996) Implications: Society, religion and politics Despite an academic and generic fascination with the process of human evolution, the creationist arguments in disagreement with evolutionary research remain influential. According to many creationist proponents, the reason why scientists have elected to give the fossils in question the name H. floresiensis is that researchers, who have accepted the idea that humans initially developed through evolution, cannot afford to imply a hypothesis that does not accord with the evolutionary ‘myth’ they have presented. Evolutionists are accused of naming ‘old human races’ by a methodology that relies on exaggerated interpretation of the variations presented between hominids, and in comparison with anatomically modern man, and thus results the declaration of the fossils as a new species. According to current creationist advocates, the H. floresiensis fossils are also a product of this methodology, and their description as a new species rests solely on evolutionist †˜preconceptions’. Predominant creationists have gone further to attest that the description of H. floresiensis as a new human species provides no support at all for the theory of evolution, but, on the contrary, reveals how forced the claims regarding it actually are (reference). The concept of the biological species is used in the present day for organisms included in the same category that are able to mate and successfully produce healthy offspring. This definition is based on mutual reproducibility as setting out the boundary criterion between species. According to creationist proponents, however, there is no means of knowing, simply by analysing and categorising the fossilised bones of organisms that lived in the past, which were able to reproduce with which. Classification based on degrees of similarities between bones, and the variations exhibited among these, may not reveal scientifically definite conclusions as some species, such as the dog, exhibit wide variation, others, such as the cheetah, are known to exhibit only narrow variation. Accordingly, when fossils belonging to extinct species are discovered, creationists attest, the variation observed may stem from one of two reasons. This variation either belongs to a species exhibiting wide variation or to a few separate species exhibiting narrow variation, yet there is no way of knowing which of the two actually applies. Indeed, Alan Walker, palaeoanthropologist and evolutionist, admits this fact by claiming that one cannot know whether or not a fossil is representative of the community to which it belongs. He further states that one cannot know whether it comes from one of the ends of the species range, or from somewhere in the middle (Locke, 1999). Evolutionists define the H. floresiensis fossils as a separate species, and regard its small endocranial volume and short skeleton as characteristics of that species. However, creationists contest this by asserting that individuals may not carry all the features in the population gene pool, and, therefore, the features exhibited by individuals may not be those generally exhibited in a given population. Therefore, the smaller the quantity of fossils analysed the greater the risk of error in assuming that their features are those of the general population. Locke (1999) has elucidated this with a simple analogy: if a palaeoanthropologist of the future discovers bones belonging to a professional basketball player, then twenty-first century man may well seem to have been a giant species. He further stated that if the skeleton belongs to a jockey, on the other hand, then humans will seem to have been short and lightweight bipeds (Locke, 1999). According to creationists, therefore, the defi nition of H. floresiensis as a separate species based on its small brain volume and short skeleton, and the assumption that all individuals possessed those same features, is a mistake, and that these fossils may well be regarded as variations seen in old human races living at that time. In relative support for the creationist viewpoint, the real surprise for evolutionists came from learning that a hominid with such a small brain volume lived not millions of years ago but only 18,000 years BP. Chris Stringer, from Londons Natural History Museum, admits this surprise to the archaeological community; that the very existence of a creature with a brain the size of a chimpanzees, but apparently a tool-maker and hunter, and perhaps descended from the worlds first mariners, illustrates how little is currently known about human evolution (Wood, 1992). Peter Brown, one of the leaders of the research team at Liang Bua, describes the bewilderment within academic circles as a result of the cranial measurements, and admits that H. floresiensis is totally incompatible with evolutionary accounts; that small stature is easy to accommodate within the evolutionary theories, but small brain size is a bigger problem to account for. According to the creationist theory advocates, the evol utionists own statements reflect the ‘heavy blow’ the fossil in question has dealt to the ‘illusory’ scenario of human evolution (Wood, 1992). The confusion with regards to the interpretations of H. floresiensis is not restricted to the disparities in hypotheses between evolutionists and creationists. Scientists have been unravelling the mysteries of when early hominids first left Africa, where they went, how many hominid species there were, and how they relate to modern humans, for more than a century. The H. erectus skull recently found in Indonesia adds a valuable piece to the fossil record, but scientists differ about where it fits in the human family tree. One particular specimen of cranium, known as Sambungmacan 4 (Sm 4), was found in the Sambungmacan district of central Java, Indonesia. It is that of a middle-aged or slightly younger male Homo erectus who had probably suffered and recovered from head wounds. Two partial skulls and the fragment of a tibia had previously been discovered in the area. It is assumed that H. erectus, and perhaps other early hominid species, began leaving Africa approximately 2 million year s ago, and fossil remains have been found in Asia, the Middle East, and Europe, indicating a widespread global distribution of individuals and communities. In addition to the media-friendly discovery of H. floresiensis, given the moniker of â€Å"The Hobbit† by the press, Indonesia, an island nation in southeast Asia, is the site of some of the earliest Homo erectus remains yet found. The relatively abundant fossil material provides scientists with an opportunity to study the evolution of the species and how it relates to modern humans. Anthropologists from the National Science Museum in Tokyo, analyzed the Sm 4 skull using digital visualization techniques, and compared it with other skulls found in Java. It is argued that morphological characteristics of early H. erectus in Java, represented by fossil finds from Trinil/Sangiran, more closely resemble those of modern humans (Baba et al., 2003). Fossil material from Ngandong, which has been dated to anywhere between 25,000 to 50,000 years old, suggests that Java H. erectus had gone off on an evolutionary tangent of its own, developing distinct features that are not shared by modern humans. It is concluded by this research that Javanese populations became progressively more isolated from other Asian H. erectus populations, and made minimal contributions to the ancestry of modern humans (Kaifu et al., 2005). At one time scientists considered it possible that modern humans were the direct descendants of Asian Homo erectus. That idea has been discarded by many scientists who now think that while African H. erectus may be ancestral to H. sapiens, Asian H. erectus was an evolutionary dead end, similar to earlier theories regarding H. neanderthalensis, rather than the immediate precursor to modern humans (Kaifu et al., 2005). However, debate continues and other specialists believe that the African version of H. erectus is dissimilar enough to belong in a separate species category called Homo ergaster. The geological complexity of the Indonesian islands makes precise dating of the fossil material difficult and controversial. Fossils found at Trinil and Sangiran range in age from approximately 1.8 million years old to maybe as young as 780,000 years old (Swisher et al., 1996). Comparatively, fossils found at Ngandong have been dated at approximately 50,000 years old. The Sm 4 specimen is believ ed to fit somewhere between these two groups in age, and therefore may be contemporary with H. sapiens.   The uncertainty of Sm 4s age lies in part with current disagreement as to whether or not all fossils from Sambungmacan represent a single fauna or are composites being derived from various age strata. Whether there is enough difference between the early fossils and the later fossils that they should be considered two separate species or a sub-species is also controversial. Based on variations in skull shape, and a lack of diversity among Javanese populations living 25,000 to 50,000 years ago, it has been concluded that Sm 4 is a transitional form, an evolutionary step taking the later Javanese populations farther away from classical Homo erectus remains found at Trinil and Sangiran (Baba et al., 2003). However, this conclusions is debated on the basis that the larger brain sizes of later materials, fossils dated at 25,000 to 50,000 years ago, are different enough that they sho uld be considered a different species or at least sub-species. Sm 4 phenotypically appears to be a lot of the other material found in Indonesia. The material is morphologically very consistent, and shows continuity within Indonesian Homo erectus. There are some features, particularly around the jaw joint that may be unique to the Ngandong fossils, however it is not clear whether the features are taxonomically significant or useful as species indicators (Baba et al., 2003).The disparities in the skulls seen in Indonesia may be a function of normal variability in any species, illustrated particularly well when considering the variations in height between ‘normal’ humans and those suffering from achondroplasia; both remain within the species of H. sapiens, however difference in stature can be remarkable. The claim by Desmond Morris, that the existence of â€Å"The Hobbit†, or H. floresiensis should destroy religion (Tattersall, 1986), is one which has been made before. Indeed, Richard Dawkins, an evolutionary biologist, still cannot understand why religion survived Darwin (Tattersall, 1986). Yet as science progresses, despite the decline of allegiance to traditional Christian churches in Western Europe, religion continues to grow world-wide in many different forms. Contemporary science, far from solving every question, often highlights the big questions which are central to human existence. This is the case with the discovery of LB1, the 18,000-year-old specimen of the new species Homo floresiensis. The find of this so-called Hobbit on Flores Island excites many academics within many fields, not least archaeology and theology, as it poses the unresolved question of what it means to be human. LB1 becomes part of this contemporary question alongside developments in science, su