Homo Erectus
The evolution of the vertebral column has been quite unclear ascribed to limited fossils of Miocene and Plio-Pleistocene hominids. However, the few samples discovered, have contributed significantly to the development of knowledge in line to evolution and understanding of the postcranial skeleton or otherwise the hominids. The distinctive features which encompass dental and cranial pieces avail the earliest evidence of hominids and their existence (Jurmain, Kilgore &Trevathan, 2009). The immediate hominid ancestors, as well as the modern humans, are discerned from apes by more perceptible features than the teeth and jaw dimensions (Jurmain, Kilgore &Trevathan, 2009). Examples of the hominids include the early forms of the hominids; Sahelanthropus, Ardipithecus, Australopithecus, Later Australopiths and early members of genus Homo- Habilis, Georgicus, erectus, erg aster, and the contemporary hominoids that included human, chimpanzee, gorilla, orangutan and bonobo (Jurmain, Kilgore &Trevathan, 2009).
Homo erectus survived approximately between two million and three hundred thousand years ago. The discovery of the fossils began in the 19th century. In tandem to this, the hominid represented a different grade- an evolutionary grouping of organisms showing a similar adaptive pattern- of evolution, which is largely different from the ancient predecessors (Jurmain, Kilgore &Trevathan, 2009). Home erectus evinced different forms of characteristics, which indicated that these hominids were like the modern humans in their adaptive patterns. The characteristics comprised of increase in body size and robustness, change in limbs proportion, and an avid encephalization (increase in the mass of the brain) (Jurmain, Kilgore &Trevathan, 2009). Similarly, there are alternate species designations for Homo erectus fossils from Africa and Eurasia, and they include Homo ergaster, a lager-brained successor to Homo Habilis from Africa and Asia, Homo antecessor, earliest Homo fossils from western Europe, and Homo heidelbergenesis, originally coined for the Mauer jaw (Haviland, Prins, Walrath & McBride, 2011).
Discovery and Fossil of Homo erectus
Different dates, sites and evolutionary significance characterize the key H. erectus discovery from Africa. A fossil of an exceptionally large individual, claimed to be a H. erectus, aged 1.4 million years, was obtained in Olduvai Gorge in Kenya. Further, another significant H. erectus fossil from East Africa was discovered in Nariokotome, West Turkana in Kenya. The fossil was a young male, with the skeleton nearly complete, and re-dated at 1.6 million years ago (Jurmain, Kilgore, Trevathan &Ciochon, 2012). In light with this, an essential fossil from East Turkana, Kenya, with a vast variation, notably among individual, was also discovered. The fossil was re-dated at 1.7 million years ago, and, it has been regarded as the oldest H. erectus specimen ever found, and, this is largely attributed to the presence of sexual dimorphism (Jurmain et al, 2012). In Europe, they were mainly two cites, Ceprano in Italy, and Dmanisi in the Republic of Georgia, with clear evidence of existence of H. erectus. In Ceprano, there was a discovery of a fossil that depicted a full blown morphology. Similarly, in Dmanisi, there was a representation of dispersed H. erectus from Africa characterized by small bodies and brains (Jurmain, Kilgore &Trevathan, 2009). In Asia, the principal discoveries were done in Java, in Indonesia and Zhoukoudian, in China. The fossils re-dated at 1.6 million years ago, and they showed massive adaption to colder environments (Jurmain, Kilgore &Trevathan, 2009).
Until about 1.8 million years ago, Africa was the only home to the bipedal primates. The bipeds, the genus homo, and the invention of the first stone tool all originated in this continent (Haviland et al, 2011). During the period of Homo erectus, the members of the genus homo had begun to spread, relatively outside Africa, and researchers have obtained fossils of this species in places like china, India, Java, Georgia, and parts of Western Europe (Haviland et al, 2011). Further, the fossils obtained from the different continents, were unified by a vast number of characteristics; nevertheless, they are a few differences within and among the Homo erectus inhabiting discrete region of Africa, Asia and Europe (Haviland et al, 2011).
The Morphology of Homo erectus
Jurmain, Kilgore and Trevathan (2009), assert that the Homo erectus population shared several common physical traits despite their inhabitation of different environments in different parts of the world. The traits encompassed a plethora of facets, which are likely to be categorized in body size, brain size, and cranial shape. In relation to the body size, the Homo erectus was immensely larger than the previous hominids, ascribed to the discovery of a complete skeleton of “Nariokotome Boy” in Nariokotome on the west side of Lake Turkana in Kenya. Further, it is also evident that the adult H. erectus weighed over fifty kilograms, with a relative height of one and half meters (Jurmain, Kilgore &Trevathan, 2009). Further, they were quite sexually dimorphic-existing in two distinct forms –as indicated by several specimens from East Africa, and the increase in height and weight, was also associated with the spectacular increase in muscular composition (Jurmain, Kilgore &Trevathan, 2009).
The brain size of the H. erectus differed in several facets from both the Homo sapiens, and the early genus of Homo, relative to cranial size (Jurmain et al, 2012). The early genus of Homo possessed a cranial content ranging from 500 to 800 centimeter cubic. On the other hand, the H. erectus exhibits a substantial brain blowup, with cranial capacity of about 700 to 1250 centimeter cubic, and an average of 900 centimeter cubic (Jurmain, Kilgore &Trevathan, 2009; Jurmain et al, 2012). Thence, it is a discernable that the brain size of H. erectus is closely colligated to the overall body size; however, the hominid was less encephalized than the subsequent members of the genus Homo (Jurmain, Kilgore &Trevathan, 2009; Jurmain et al, 2012).
In addition to this, the crania of the H. erectus revealed a unique and distinct shape, largely attributed to the increased brain size. The ramifications of the cranium were heavily built and depicted through thick cranial bone, large brow ridges above the eyes, and a projection of nuchal torus at the back of the skull, on the occipital bone (Jurmain, Kilgore &Trevathan, 2009; Jurmain et al, 2012). The cranium was also broader at the base, with a maximum cranial breadth below the earlobe, hence acquiring a pentagonal shape. Besides, the brain sheath was long and low, drawing back from the large brow ridges, forming a little forehead development (Jurmain, Kilgore &Trevathan, 2009; Jurmain et al, 2012).
Tools in H. erectus Population
The temporal span of the H. erectus comprised of two different stone tools. The species began by using Oldowan tools, which consisted of side scraper, point, end scrapper and burin, and they were spread to Dmanisi, Java and Spain by the H. erectus immigrants (Jurmain et al, 2012). Another set of tools, referred to as Acheulian was invented about 1.4 million years ago, and the significant change made in the set was the replacement of the Oldowan choppers by more sophisticated hand axe, referred to as a Biface. The tools worked on both sides, and they were shaped by regular blows giving them a larger and finer cutting edge than most of the chopper tools (Haviland et al, 2011). The introduction of this set was due to the large brain. Most of the tools originated from stones, and the Acheulian tool users, would pick suitable pieces of stones as they transported raw materials (Jurmain et al, 2012).
Sociality
In line with this, fossils ascertained in southern Africa, attest that the H. erectus may have started using fire by one million years ago (Haviland et al, 2011). The fire gave them more control over their environment, through allowing them to progress with their activities after dark, and scare aware wild animals and predators. Further, the fire supplied them with warmth, and, it lit the caves in which they dwelt in (Haviland et al, 2011). During this period, the H. erectus also developed notable skills in cooking. They developed the general ability to modify food culturally through cooking, and consequently it led reduction of tooth size and jaw (Haviland et al, 2011).
H. erectus were hunters, and the main intent was to procure meat, animal hides, horns, bones and sinew. The earliest evidence manifesting the hunting technology of these hominids was a bunch of 400, 000 years old spears attained in a peat bog in Northern German (Haviland et al, 2011). The invention of fire and their hunting and gathering activities altered their diet and eating habits. They fed on meat from wild animals, ate insects, and gathered honey, roots, bird eggs, and berries which were also part of their diet. Consequently, the diet was exceedingly indispensable, since it aided in changing and maintaining the size of the brain, and in the provision of enough energy for the big body (Jurmain, Kilgore &Trevathan, 2009).
Relationship between Homo erectus and other Hominids
The smaller teeth and larger brains of H. erectus appear to mark the continuation of a successful trend, highly observable in Homo sapiens (Haviland et al, 2011). The increased body size reduced sexual dimorphism and the upright postures of the H. erectus are the newly derived features that gave rise to the evolution of Homo sapiens (Haviland et al, 2011). In contrary, the hominid species in existence before the H. erectus, had different behavior, and brain expansion and tool used played a significant role in the evolution of the genus Homo (Haviland et al, 2011). The brain size of these species were smaller compared to H. erectus for instance the brain size for Australopithecus ranged from 310 to 530 cubic centimeters (Haviland et al, 2011). Similarly, the hominids were acutely primitive, and they utilized primitive tools that were highly ineffective. The basic diet was rough vegetables and insects (Jurmain, Kilgore &Trevathan, 2009).
Conclusion
Concisely, with the evolving of H. erectus, there is a clear manifestation of a complex interplay among biological, cultural, and ecological factors. Moreover, there is the development of primitive technology and social organization attributed to increase in brain size and complexity. The H. erectus also exhibit a different morphological structure from the pre-existing hominids species, characterized by, upright postural, reduced teeth and jaw size, and a large body size. Conventionally, there was a transition in the cultural adaptation, ascribed to the tools used, which were more complex and proficient, a controlled use of fire, and cooking. Undoubtedly, they had adept methods for food gathering and hunting, and this led to the transformation of H. erectus to the next species: Homo sapiens. In light with this, there is a lot of presented evidence on the discovery of H. erectus, thus limited controversy on the existence and discovery of H. erectus.
References
Haviland, A. W., Prins, L. E. H., Walrath, D. & McBride, B. (2011). Anthropology: The Human Challenge (13th Ed.). Belmont, CA: Wadsworth, Cengage Learning.
Jurmain, R., Kilgore, L., Trevathan, W. & Ciochon, L. R. (2012). Introduction to Physical Anthropology. Belmont, CA: Wadsworth, Cengage Learning.
Jurmain, R., Kilgore, L. & Trevathan, W. (2009). Essentials of Physical Anthropology (7th Ed.). Belmont, CA: Wadsworth, Cengage Learning.
