Homo Floresiensis Research Paper
Homo Floresiensis: A Creature of Controversy Since its discovery in 2004, Homo floresiensis has sparked tremendous controversy among archaeologists across the world (Aiello, 2010:169). Found on the island of Flores (hence the name), located in the midst of Indonesia, the fossil remains present a dilemma that is often compared to that surrounding the Neanderthals (Liberman, 2009:41). Simply put, the discovery of Homo floresiensis challenges the prevailing record of human history. Homo floresiensis contain characteristics from a multitude of species throughout the course of human history, including Homo sapiens. The problem currently plaguing archaeologists narrows down to the taxonomic status, as well as evolutionary position of Homo floresiensis,
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and even more compelling, whether they could possibly share an evolutionary history with modern humans.
The skeleton found by archaeologists was relatively complete, including a cranium, mandible, the right half of the pelvis, the right femur, and tibia, additional fragmented bones of the left leg, both hands and feet, as well as the vertebral column (textbook pg. 120). Among their findings however, the archaeologists were shocked to discover just how tiny Homo floresiensis was. Standing at only 1.06 meters, Homo Floresiensis was much shorter than any species of Homo. In fact, its height was much more closely related to that of an Austrolepithicine, which went extinct approximately two million years ago, about 1.9 million years before Homo Floresiensis even evolved (Meijer et al., 2010:1002).
Additionally, its cranial capacity is estimated at only 417cc, which compares to that of a modern newborn, or the size of an average chimp (Lieberman, 2009:41). This is about 50% less than that of the average Homo Habilis, and much closer to the size of an Austrolepithecine (Book). However, this does not mean that Homo floresiensis was not intelligent. In the cave in which the skeletal remains were found, evidence of charred bone and clusters of fire-cracked rocks suggest the controlled use of fire, as well as stone tools. Remains of Stegadon, the only other large mammal on the island, were also found, some of them with cut marks, suggesting that Homo floresiensis may have even known how to hunt (Aiello 2010:169).
The facial and cranial features of Homo floresiensis can be attributed to a range of primitive and derived species. The shape of the cranium and many of its facial characteristics are most similar to that of H. Erectus. Additionally, Homo floresiensis’ vertical face, no snout, and teeth generally resemble those of Homo origin (Lieberman, 2010:42). However, while the facial construction features far less prognathous than generally attributed to members of austrolepithicus, the symphysis, or closures of joints, located within the jaw are more characteristic of Austrolepithecus (Aiello, 2010:171). The size and shape of Homo floresiensis are consistent with a high fiber, plant based diet, very similar to that of Homo habilis. While in both circumstances there is evidence of hunting game, it is not thought to have been their primary mode of subsistence. Hunting, gathering, and scavenging seem to have been much more prominent (book, 115; Aiello, 2010:172).
Furthermore, Homo Floresiensis exhibits an inhuman body ratio. It showcases “long arms and relatively short legs, robust limb bones and exceptionally long feet,” (Meijer 2010:1002). Particularly peculiar are the structure and mechanics of the wrists, shoulder, and feet. The wrist bones seem to envelop the characteristics of the primitive African ape-human clade, because Neanderthals, modern humans, and Homo antecessor share a common wrist morphology that forms during embryogenesis (Tocheri et al., 2007). The shoulder morphology also seems to predate that of Homo antecessor and is more similar to that of Homo erectus. It is characterized by a short clavicle and low torsion angle. These conditions can be explained in modern humans by pathological conditions, however, it is much more likely that they are simply characteristic of morphology found in earlier geographically dispersed hominins (Aiello, 2010:173). Homo floresiensis’ feet, however, bring about the greatest controversy. The length of the feet, 20 cm, is much longer than any archaeologist would expect to find in a human of Homo floresiensis’ stature. They are, in fact, much more characteristic of an ape or an australopith. Moreover, the feet contain “long, curved, and robust lateral toes; a short big toe; and a weight-bearing process on a crucial bone, the navicular,” which aids in support of the human arch (Lieberman, 2009:41). The structure of the feet suggests that the Homo floresiensis was capable of walking, but was not well adapted to run. This is due in large to the muscular interior of the arch being either weak or flat, disenabling them from initiating a running stride (Lieberman, 2009:42).
It is thought that the species Homo floresiensis existed between 74,000 and 16,000 years ago, however the majority of the skeletons found date back to 18,000-16,000 years ago.
The skeletons found were variously associated with stone tools and Stegadon, the Komodo dragon, giant rats, bats, and other animals characteristic of the time within Liang Bua cave, which is located in western Flores. Because the uppermost of the two layers containing Homo floresiensis are covered in deposit, archaeologists have speculated whether or not the extinction of H. floresiensis and Stegadon could have been due to a volcanic eruption around 17,000 years ago, or whether climate change and the arrival of modern humans are to blame (Aiello, 2010:169).
In total, Homo floresiensis’ characteristics of a small brain and cranium, short stature, length and robustness of limbs, and structure and length of feet are analogous to that of an australopthicine, however, the elongated, less prognathous facial structure, teeth, and shape of the brain are considered to be characteristics derived from a species of Homo (Meijer et al., 2010:1002). This discrepancy in analogous structures to any known ancient species fuels the controversy throughout the field of anthropology; who were the Homo floresiensis, and from whom were they …show more content…
derived?
There are two main hypotheses regarding the phylogeny of H. floresiensis: 1) the species is unlike any organism ever found, and thus requires its own genus; 2) the species is a late surviving species of the genus Homo (Aiello, 2010:176).
When the skeletal remains of H. floresiensis were first discovered, archaeologists proposed a new genus, Sundanthropus floresiensis, to explain the phylogeny of the material. Their rationalization lay in the fact that H. floresiensis was simply too different from any of the species of Homo and did not share enough common characteristics to warrant its placing into the genus. The skeletal remains were interpreted as “being unlike modern H. sapiens and represented a mosaic of features unobserved in any other hominin,” (Aiello, 2010:171).
However, upon further investigation, archaeologists began to point out the remarkable similarities in cranial construction to the genus Homo.
To explain the significant discrepancy in cranial and brain size, archaeologists suggested two main hypotheses: 1) the size of the entire skeleton was due to insular dwarfism, a phenomenon in which species living on islands are smaller than species living on large continents; 2) the size of the cranium and brain is due to a pathological disorder, such as microcephaly, a disorder stemming from incomplete brain development. The evidence surrounding the theory of insular dwarfism include a study of extinct Malagasy dwarf hippos, which proved that insular dwarfism can result in a brain size smaller than that projected by scaling models. Because of this, the decrease in brain size in H. floresiensis from that of its predecessors could be explained by an adaptation to the limited energy resources provided by the island, meaning that it would be more energy efficient to be small (Meijer et al., 2010). As of now, this is the best evidence presented in favor of the hypothesis of insular dwarfism (Aiello, 2010:172). Conversely, evidence supporting a pathological disorder includes cladistics analysis that upholds the theory. The first cladogram places H. floresiensis between Homo rudolfensis and the clade including H. habilis, while the second places it between H. habilis and the clade including H. georgicus. However, a pathological disorder does
not account for the other skeletal differences between H. floresiensis and other hominins, such as its height, disproportionate arms and legs, and structure of feet, wrists, and shoulder (Aiello, 2010:174).
In conclusion, until further evidence arises, the controversy surrounding H. floresiensis will undoubtedly continue. In order for one of they hypotheses to prevail, evidence discounting all other possibilities must arise. Until then, the phylogeny of H. floresiensis will remain an archaeological mystery, consistently defying human prehistory norms.
and even more compelling, whether they could possibly share an evolutionary history with modern humans.
The skeleton found by archaeologists was relatively complete, including a cranium, mandible, the right half of the pelvis, the right femur, and tibia, additional fragmented bones of the left leg, both hands and feet, as well as the vertebral column (textbook pg. 120). Among their findings however, the archaeologists were shocked to discover just how tiny Homo floresiensis was. Standing at only 1.06 meters, Homo Floresiensis was much shorter than any species of Homo. In fact, its height was much more closely related to that of an Austrolepithicine, which went extinct approximately two million years ago, about 1.9 million years before Homo Floresiensis even evolved (Meijer et al., 2010:1002).
Additionally, its cranial capacity is estimated at only 417cc, which compares to that of a modern newborn, or the size of an average chimp (Lieberman, 2009:41). This is about 50% less than that of the average Homo Habilis, and much closer to the size of an Austrolepithecine (Book). However, this does not mean that Homo floresiensis was not intelligent. In the cave in which the skeletal remains were found, evidence of charred bone and clusters of fire-cracked rocks suggest the controlled use of fire, as well as stone tools. Remains of Stegadon, the only other large mammal on the island, were also found, some of them with cut marks, suggesting that Homo floresiensis may have even known how to hunt (Aiello 2010:169).
The facial and cranial features of Homo floresiensis can be attributed to a range of primitive and derived species. The shape of the cranium and many of its facial characteristics are most similar to that of H. Erectus. Additionally, Homo floresiensis’ vertical face, no snout, and teeth generally resemble those of Homo origin (Lieberman, 2010:42). However, while the facial construction features far less prognathous than generally attributed to members of austrolepithicus, the symphysis, or closures of joints, located within the jaw are more characteristic of Austrolepithecus (Aiello, 2010:171). The size and shape of Homo floresiensis are consistent with a high fiber, plant based diet, very similar to that of Homo habilis. While in both circumstances there is evidence of hunting game, it is not thought to have been their primary mode of subsistence. Hunting, gathering, and scavenging seem to have been much more prominent (book, 115; Aiello, 2010:172).
Furthermore, Homo Floresiensis exhibits an inhuman body ratio. It showcases “long arms and relatively short legs, robust limb bones and exceptionally long feet,” (Meijer 2010:1002). Particularly peculiar are the structure and mechanics of the wrists, shoulder, and feet. The wrist bones seem to envelop the characteristics of the primitive African ape-human clade, because Neanderthals, modern humans, and Homo antecessor share a common wrist morphology that forms during embryogenesis (Tocheri et al., 2007). The shoulder morphology also seems to predate that of Homo antecessor and is more similar to that of Homo erectus. It is characterized by a short clavicle and low torsion angle. These conditions can be explained in modern humans by pathological conditions, however, it is much more likely that they are simply characteristic of morphology found in earlier geographically dispersed hominins (Aiello, 2010:173). Homo floresiensis’ feet, however, bring about the greatest controversy. The length of the feet, 20 cm, is much longer than any archaeologist would expect to find in a human of Homo floresiensis’ stature. They are, in fact, much more characteristic of an ape or an australopith. Moreover, the feet contain “long, curved, and robust lateral toes; a short big toe; and a weight-bearing process on a crucial bone, the navicular,” which aids in support of the human arch (Lieberman, 2009:41). The structure of the feet suggests that the Homo floresiensis was capable of walking, but was not well adapted to run. This is due in large to the muscular interior of the arch being either weak or flat, disenabling them from initiating a running stride (Lieberman, 2009:42).
It is thought that the species Homo floresiensis existed between 74,000 and 16,000 years ago, however the majority of the skeletons found date back to 18,000-16,000 years ago.
The skeletons found were variously associated with stone tools and Stegadon, the Komodo dragon, giant rats, bats, and other animals characteristic of the time within Liang Bua cave, which is located in western Flores. Because the uppermost of the two layers containing Homo floresiensis are covered in deposit, archaeologists have speculated whether or not the extinction of H. floresiensis and Stegadon could have been due to a volcanic eruption around 17,000 years ago, or whether climate change and the arrival of modern humans are to blame (Aiello, 2010:169).
In total, Homo floresiensis’ characteristics of a small brain and cranium, short stature, length and robustness of limbs, and structure and length of feet are analogous to that of an australopthicine, however, the elongated, less prognathous facial structure, teeth, and shape of the brain are considered to be characteristics derived from a species of Homo (Meijer et al., 2010:1002). This discrepancy in analogous structures to any known ancient species fuels the controversy throughout the field of anthropology; who were the Homo floresiensis, and from whom were they …show more content…
derived?
There are two main hypotheses regarding the phylogeny of H. floresiensis: 1) the species is unlike any organism ever found, and thus requires its own genus; 2) the species is a late surviving species of the genus Homo (Aiello, 2010:176).
When the skeletal remains of H. floresiensis were first discovered, archaeologists proposed a new genus, Sundanthropus floresiensis, to explain the phylogeny of the material. Their rationalization lay in the fact that H. floresiensis was simply too different from any of the species of Homo and did not share enough common characteristics to warrant its placing into the genus. The skeletal remains were interpreted as “being unlike modern H. sapiens and represented a mosaic of features unobserved in any other hominin,” (Aiello, 2010:171).
However, upon further investigation, archaeologists began to point out the remarkable similarities in cranial construction to the genus Homo.
To explain the significant discrepancy in cranial and brain size, archaeologists suggested two main hypotheses: 1) the size of the entire skeleton was due to insular dwarfism, a phenomenon in which species living on islands are smaller than species living on large continents; 2) the size of the cranium and brain is due to a pathological disorder, such as microcephaly, a disorder stemming from incomplete brain development. The evidence surrounding the theory of insular dwarfism include a study of extinct Malagasy dwarf hippos, which proved that insular dwarfism can result in a brain size smaller than that projected by scaling models. Because of this, the decrease in brain size in H. floresiensis from that of its predecessors could be explained by an adaptation to the limited energy resources provided by the island, meaning that it would be more energy efficient to be small (Meijer et al., 2010). As of now, this is the best evidence presented in favor of the hypothesis of insular dwarfism (Aiello, 2010:172). Conversely, evidence supporting a pathological disorder includes cladistics analysis that upholds the theory. The first cladogram places H. floresiensis between Homo rudolfensis and the clade including H. habilis, while the second places it between H. habilis and the clade including H. georgicus. However, a pathological disorder does
not account for the other skeletal differences between H. floresiensis and other hominins, such as its height, disproportionate arms and legs, and structure of feet, wrists, and shoulder (Aiello, 2010:174).
In conclusion, until further evidence arises, the controversy surrounding H. floresiensis will undoubtedly continue. In order for one of they hypotheses to prevail, evidence discounting all other possibilities must arise. Until then, the phylogeny of H. floresiensis will remain an archaeological mystery, consistently defying human prehistory norms.