THE EVOLUTION OF HUMAN
Human evolution refers to the slow process of change from one stage to another stage which is better than the previous. Scientific evidence shows that the physical and behavioral characteristics shared by all people evolved over a period of about 6 million years. One of the earliest defining human characteristic was bipedalism-walking on two legs(limbs) as the primary form of locomotion-evolved more that 4 million years ago. Other important human characteristics such as a large and complex brain, the ability to make and use tools, and the capacity for language developed more recently. Many advanced characteristics including symbolic expression such as art, and elaborate cultural diversity emerged mainly during the past 100000 years.All organisms are related by descent from common ancestors. Humans and other mammals descend from shrew like creatures that lived more than 150 million years ago (Ma).From the time of Darwin, Huxley, and Haeckel until soon after the turn of the twentieth century, humans’ closest relatives were regarded as being the African apes, the chimpanzee and gorilla, with the Asian great ape, the orangutan, being considered to be somewhat separate. From the 1920s until the 1960s, humans were distanced from the great apes, which were said to be an evolutionarily closely knit group.
Figure 1: Shifting patterns:Between the beginning of the twentieth century and today..
Ideas about the relationships among apes and humans have moved full circle.This shift of opinions has, incidentally, been paralleled by a related shift in ideas on the location of the “cradle of mankind.” Darwin plumped for Africa, because that’s where our closest relatives, the chimpanzee and gorilla, live; Asia became popular in the early decades of the twentieth century; and Africa has once again emerged as the focus. The different views on the origin of modern humans are, however, imbued with different perspectives of this issue. Some of the Historian who supports this theory of evolution of man are,Y. C. Loring Brace and Milford Wolpoff, both of the University of Michigan.Elwyn Simons,David Pilbeam,Dr.Louis Leakey and G. E. Pilgrim (1927).
The Evolution of Life
About 67 million years ago, a family of mammals known as primates a diverse group that share similarities such as increased brain size, stereoscopic vision, grasping hands and feet, longer periods of offspring dependence on their mothers, a complex social life, and enhanced learning abilities first appeared in the fossil record. Early primates include ancestors of modern prosimians, such as lemurs, tarsiers, and lorises. Later primates that appeared in the fossil record include anthropoids, such as monkeys, apes, and humans who shared a common ancestor and have some fundamental similarities with one another. Many people hold a common misconception about human evolution they mistaken belief that humans descended from modern apes such as the gorilla and chimpanzee. This is a highly inaccurate interpretation of both Charles Darwin’s thesis and contemporary scientific theories of human evolution that suggest that millions of years ago some animals developed certain characteristics through evolutionary processes that made them precursors of later primates, including humans. Darwin posited that humans share a common ancestor with living apes, but evolved along lines completely different from modern gorillas and chimpanzees.
Recently, paleontologists discovered significant fossils in Spain of a primate that has been classified as the “missing link” or common ancestor between the various ape species of gorillas, chimpanzees, orangutans, and humans. This creature, named Pierolapithecus catalaunicus, has physical traits that connect it with early apes and early hominids or ancestors of the human lineage. Pierolapithecus catalaunicus had a very flat face with nostrils that are in almost the same plane as its eye sockets. Its face would resemble that of a modern gorilla today. Paleoanthropologists believe that this creature existed in Africa and Europe during the Miocene epoch, about 13 million years ago (Moyà-Solà et al. 2004)
The theory of evolution holds that Humans belong to the animal kingdom and that man has evolved over the years. Man is a primate just as apes like gorillas, chimpanzees and monkeys. However, man belongs to the family of hominidae, while apes belong to the family of pongidae. Man according to Darwin developed over the years from his ape-like ancestors. Origin of Man.The origin of man can be discussed by using two main theories. The main discussion is based on when and how man came into existence. The main theories are the religious theory of creation and the theory of the evolution of man.
Theory of the Evolution of Man
The theory of evolution explains that mankind changed gradually from ape-like ancestors to human being. This theory states that man, through a combination of environmental and genetic factors, emerged as a species to produce the various ethnicities seen today, while modern apes evolved on a separate evolutionary pathway. These changes also went hand-in-hand with improved methods for obtaining foods, shelter and clothing, through which modern man developed. It is said that modern man appeared about 50000 years ago. These gradual changes of man are called the evolution of man. This theory emphasizes that man came into existence together with animals more than 30000000 years ago. At first man belonged to the family of Primates that included gorillas, apes, monkeys, and chimpanzees. These animals lived in forests walking on four legs with their bodies covered with a lot of hair. Because of environmental changes, particularly the diminishing of forests, some of the apes started to live in open grasslands, which forced them to adapt, led to changes in the function of limbs. The fore limbs, instead of being used for walking, started to be used to make and use tools. The hind limbs were used for standing and walking. The transition from using four limbs to two limbs is called Bipedalism.
These changes went together with the development of man’s brain. Therefore, the change from four limbs to two limbs, and the change in the brain are crucial to the theory of the evolution of man. As distinct from other animals, man became capable of designing tools for specific purposes. Therefore according to the theory of evolution, man originated from primates.
STAGES OF EVOLUTION OF MAN.
These are the first creatures from which the modern man evolved. The primates were chimpanzees, gorillas, monkeys and apes. These animals lived in forests, walking on four limbs and their bodies were covered with a lot of hair.
Characteristics of the Primate Stage
- They were fully covered by a lot of hair
- They walked on four limbs.
- They lived in dense forest areas.
- They were characterized by low or mental abilities (small brain size).
Figure 2: Example of primate(Gorilla)
The first systematic attempt to account for the differences between primates and other mammals was made by T. H. Huxley, in his 1863 book, Evidence as to Man’s Place in Nature. In the early twentieth century, the British anatomists Grafton Elliot Smith and Frederic Wood Jones continued this quest. Ancestral primates and, by extrapolation, humans were different from other mammals, they argued, because of adaptation to life in the trees hence the arboreal hypothesis of primate origins. Grasping hands and feet provided a superior mode of locomotion, according to these scientists, while vision was a more acute sensory system than olfaction in among the leaves and branches. As Cartmill noted, however, “The arboreal theory was open to the most obvious objection that most arboreal mammal’s opossums, tree shrews, palm civets, squirrels, and soon lack the short face, close-set eyes, reduced olfactory apparatus, and large brains that arboreal life supposedly favored.”
The British anthropologists valiantly defended their theory, invoking ingenious and often inconsistent lines of argument. In any case, the arboreal theory was modified and extended in the 1950s by another British researcher, the eminent Sir Wilfrid Le Gros Clark. It continued to thrive for another two decades, until Cartmill felled it in 1972. In reassessing the arboreal theory in the early 1970s, Cartmill applied biologists’ most powerful tool comparative analysis. “If progressive adaptation to living in trees transformed a tree shrew-like ancestor into a higher primate, then primate-like traits must be better adapted to arboreal locomotion and foraging than their antecedents,” reasoned Cartmill. In other words, if primates are truly the ultimate in adaptation to arboreal life, you would expect that they would be more skillful aloft than other arboreal creatures. “This expectation is not borne out by studies of arboreal nonprimes,” he noted. Squirrels, for instance, do exceedingly well with divergent eyes, a long snout, and no grasping hands and feet, often displaying superior arboreal skills to those of primates. “Clearly, successful arboreal existence is possible without primate-like adaptations,” concluded Cartmill. If the close-set eyes and grasping hands and feet were an adaptation to something other than arboreality, what was it? Once again Cartmill used the comparative approach to find an answer that formed the basis of the visual predation hypothesis. Boldly put, the hypothesis states that the suite of primate characteristics represents an adaptation by a small arboreal mammal to stalking insect prey, which are captured in the hands.
Theories of the origin of primate adaptations
The first systematic attempt to account for the differences between primates and other mammals was made by T. H. Huxley, in his 1863 book, Evidence as to Man’s Place in Nature. In the early twentieth century, the British anatomists Grafton Elliot Smith and Frederic Wood Jones continued this quest. Ancestral primates and, by extrapolation, humans were different from other mammals, they argued, because of adaptation to life in the trees hence the arboreal hypothesis of primate origins. Grasping hands and feet provided a superior mode of locomotion, according to these scientists, while vision was a more acute sensory system than olfaction in among the leaves and branches. As Cartmill noted, however, “The arboreal theory was open to the most obvious objection that most arboreal mammal’s opossums, tree shrews, palm civets, squirrels, and soon lack the short face, close-set eyes, reduced olfactory apparatus, and large brains that arboreal life supposedly favored.
The British anthropologists valiantly defended their theory, invoking ingenious and often inconsistent lines of argument. In any case, the arboreal theory was modified and extended in the 1950s by another British researcher, the eminent Sir Wilfrid Le Gros Clark. It continued to thrive for another two decades, until Cartmill felled it in 1972. In reassessing the arboreal theory in the early 1970s, Cartmill applied biologists’ most powerful tool comparative analysis. “If progressive adaptation to living in trees transformed a tree shrew-like ancestor into a higher primate, then primate-like traits must be better adapted to arboreal locomotion and foraging than their antecedents,” reasoned Cartmill. In other words, if primates are truly the ultimate in adaptation to arboreal life, you would expect that they would be more skillful aloft than other arboreal creatures. “This expectation is not borne out by studies of arboreal nonprimes,” he noted. Squirrels, for instance, do exceedingly well with divergent eyes, a long snout, and no grasping hands and feet, often displaying superior arboreal skills to those of primates. “Clearly, successful arboreal existence is possible without primate-like adaptations,” concluded Cartmill.
Boldly put, the hypothesis states that the suite of primate characteristics represents an adaptation by a small arboreal mammal to stalking insect prey, which are captured in the hands. Cartmill sought individual elements of the primate suite in a range of other species. For instance, chameleons have grasping hind feet, which they use to steady themselves when approaching insect prey on slender branches. Some South American opossums show similar behavior, capturing their prey by hand or mouth. And, of course, the convergence of the eyes is found in many predatory animals that need to be able accurately to judge distance, such as cats, owls, and hawks. “Most of the distinctive primate characteristics can thus be explained as convergence with chameleons and small bush-dwelling marsupials (in the hands and feet) or with cats (in the visual apparatus),” concluded Cartmill.
“This implies that the last common ancestor would have subsisted much as modern tarsiers, the mouse lemur, and some lorises do today.” These species should not be considered “living fossils” because, like humans, they are also the products of 60 million years of evolution. It is simply that their ecological niche resembles the niche occupied by their ancestors. Cartmill’s visual predation hypothesis has recently been challenged by American primatologist Robert Sussman. He points out that many primate species locate their prey by smell or hearing, so that visual predation by itself is not sufficient to explain this suite of primate adaptations. He also argues that the earliest primates evolved at a time when flowering plants were in the midst of an evolutionary diversification. Grasping hands and feet would have enabled small primate species to move with agility in terminal branches rich with fruit; keen visual acuity would allow fine discrimination of small food items.
The origin and evolution of primates
The overall evolutionary pattern of primates remains unsettled, although the origin of the order has recently been estimated at close to 85 million years rather than the 65 million that has generally been assumed. Some kind (or kinds) of species ancestral to all primates survived the mass extinction 65 million years ago that spelled the end of the Age of Reptiles, with the dinosaurs being the most notorious of the extinctions. Soon into the subsequent Age of Mammals, “primates of modern aspect” appeared approximately 50 million years ago, beginning an adaptive radiation that included an increase in range of body size and a concomitant broadening of diet. The 200 modern species represent the remains of that adaptive radiation, which, in total, probably gave rise to some 6000 species. The known fossil record provides only the briefest of glimpses of this radiation, a sketchy outline at best; somewhere between 60 and 180 fossil primate species can be recognized. Some researchers consider the earliest primate group to be the plesiadapiforms, the best-known specimen.
Figure 3.The image of Three views of primate evolution:
A good deal of uncertainty exists over the pattern of primate evolution. Until recently most opinion was divided between schemes (a) and (b), which show differences over the origin of anthropoids. A third view (c) has also been proposed, which postulates a third, early group of primates that was ancestral to modern anthropoids. Based on the most recently discovered fossil evidence, however, scheme (a) is now most strongly supported.
Social organization in Primates
Social organization is a pattern of relationships between and among individuals and social groups.To obtain a feel for some of the details of social organization and the range to be found among primates, its important first to survey the social lives of the apes: gibbon, orangutan, chimpanzee, and gorilla.Gibbons and siamangs are the smallest group of apes live in forests in Southeast Asia. The basic social structure of these highly acrobatic, arboreal creatures is very similar as they consist a monogamous mating pair plus as many as three dependent offspring.
Gibbons are territorial, and eat a diet of fruit and leaves. On reaching maturity, the offspring leave the natal group and eventually establish one of their own by pairing with another young adult of the opposite sex. Mature males and females have essentially the same body size. Gibbons provide a good example of life-long monogamy. The other Asian ape, the orangutan, is much larger than the gibbon and pursues a very different lifeway, although it is also highly arboreal. The core of its social organization is a single mature female and her dependent offspring. The mother and offspring occupy a fairly well-defined home range, which usually overlaps with that of one or more other mature females and their offspring. In contrast, males are rather solitary creatures, with each occupying a large territory that usually contains the home ranges of several mature females with whom he will mate. Males, which are about twice the size of females, actively defend their territories against incursion by other males.
The mating system is therefore one of a loosely organized harem, with one male mating with several females. Gorillas, the largest of the apes, live in the forests of central and West Africa. These animals follow a mating system similar to that of the orangutan-unimale polygyny although their ecology and organization are distinctly different. Predominantly terrestrial animals that live on low-quality herbage found in abundant but widely dispersed patches, gorillas live in close groups composed of from 2 to 20 individuals. The adult male the silver back has sole mating access to the mature females, whose immature offspring also live in the group. Mature males compete for control of the group. Nevertheless, a female, usually a young adult, will sometimes transfer from one group to another, seemingly as a matter of free choice. New groups are established when a lone silverback begins to attract transferring females. As with orangutans, male gorillas are twice the size of females.
Chimpanzees, which are terrestrial and arboreal omnivores, live in rather loose communities composed of between 15 and 80 individuals, representing a mixture of mature males and mature females and their offspring. Unlike savannah baboons, which live in close, cohesive troops of mature males, related females, and their offspring, sometimes numbering 200 individuals in total, chimpanzee communities are maintained by occasional contact between males and females. The core of chimpanzee social life is a female with her offspring; these units are often found by themselves but sometimes link up with other females and their offspring. Each female maintains a core area, which usually overlaps with that of one or more other females. By contrast with orangutans, single chimpanzee males do not maintain exclusive control of a group of female home ranges. Instead, a group of males defends the community range against the males of neighboring communities. Mating in chimpanzee communities is promiscuous, with each estrus female copulating with several males. The social organization is therefore known as multimale polygyny.
A key feature of chimpanzee social organization is that, unlike in the general pattern of multimale societies among primates, males remain in their natal group while young adult females transfer or are sometimes kidnapped to other communities. As a result, the adult males who are cooperating to defend their community are usually closely related to one another. Adult male chimpanzees are typically 25 to 30 percent larger than females. Among the apes, then, one finds monogamy, unimale polygyny, and multimale polygyny.
Figure 4. Primates social organization:
Causes of social organization
The fact that such a rich array of social organizations exists among primates as a whole, and among the apes in particular, surely indicates that a rather complex set of processes underlies them. For each species, some kind of interaction must take place between its basic phylogenetic heritages its anatomy and physiology and key factors in the environment. Thus, different species will probably react differently to the same environmental factors, creating at least part of the observed diversity.
One of the most frequently advanced explanations of the benefits of group living has been defense against predation. Even though it may be more conspicuous than a one individual, a group can be more vigilant and more challenging.
Effective defense against predators has been observed in many group living species of primate. It is certainly true that terrestrial species, which face greater risk from predators than arboreal animals, live in larger groups and commonly include more males in the group; in addition, the males in such species frequently are equipped with large, dangerous canine teeth. Protection against predation may to some degree be a consequence, not the primary cause, of group living.
Food distribution has also been suggested as a trigger of social organization. Groups might be more efficient than individuals at discovering discrete patches of food, for instance, or, where food patches are defensible by territorial.
Scientists have traditionally used physical characteristics that reflect shared adaptive histories in classifying primates—placing them into various families, genera, and species. Humans and their immediate ancestors have traditionally been placed in their own family— Hominidea based on similarities in their anatomy However, the unraveling of genetic codes has revealed the specific genetic links between living primate species from the other apes. Anthropologists have been evaluating hypotheses regarding hominid evolution for the past 150 years. Hominids, the family of primates that includes the direct ancestors of humans, share certain subtle features in their teeth, jaws, and br ain. However, by far the major characteristic that identifies them as a distinct group is the structural anatomy needed for bipedalism, the ability to walk erect on two legs.Bipedalism is not a characteristic of modern apes, such as chimpanzees and gorillas, which can stand upright but do most of their walking on four limbs. Fossil evidence of the early evolution of the hominids remains very incomplete.
Homo habilis lived between 1500000 and 750000 years ago. Homo habilis, however, is relatively common at Olduvai between 1.8 and 1.6Million years ago, though it is not definitively recognized in contemporaneous deposits in the Turkana Basin. The skull of Homo habilis was discovered in Olduvai Gorge, which is found in Arusha region in Tanzania.Homo habilis was given the name of Australopithecus or Zinjanthropus. Homo habilis could walk upright like modern humans, but could probably also climb trees to sleep, feed or escape predators. An enormous amount of fossil evidence for at least six different species of australopithecines has been discovered in Africa. The most complete early form of this genus, found in the Afar region of Ethiopia, is known as Australopithecus afarensis. It was discovered in 1974 by a joint American–French team of paleoanthropologists led by Donald Johanson.The process in which Homo Habilis walk upright by using two limbs is called Bi pedalism.
Features of Homo Habilis.
- Their hands and feet had a combination of ancient and modern features, expected of an early ancestor
- He was the First Homo specie to create and use stone tools for hunting and daily life.
- Homo habilis depicted the ability to make better tools than his predecessors. That is why he was referred to as man with ability.
Types of Australopithecines
- Australopithecus Afarensis
- Australopithecus Anamensis
- Australopithecus africanus.
- Australopithecus Robustus.
He is aged between 4.2 and 3.9 million years ago and is believed to be one of the oldest Australopithecines.
Evidence of his existence is obtained from the Reconstruction of Material consisting of 9 fossils from Kanapoi in Kenya and 12 fossils from Allia Bay in Kenya found by Dr. Meave Leakey, Dr. Allan Walker and the four fossil hunters (Kamoya Kimeu, Wambua Mangao, Nzube Mutiwa and Samuel Ngui.).The fossil remains comprising a lower jaw .He had relatively large canines.
The homid was aged between 3.9 and 3.0 million years ago. Its Name is derived from Afar Depression in Ethiopia.
- He Had Apelike face and human-like teeth. He was small in stature and Bipedal, but Walked bent over, not fully upright.
- They had a bony ridge over the eyes, a low forehead, a flat nose, and also they had no chin.
Australopithecus Africanus (A. Gracilis)
Australopithecus Africanus existed between 3 and 2.5 million years ago. A. africanus was slenderly built, or Gracile (Gracile means slender) with a height of 1.5m.Was significantly more like modern humans than A. Afarensis, with a larger brain and more humanoid facial features. ~ Had large teeth, jaws and skull.Australopithecus Africanus has been found at only four sites in southern Africa — Taung (1924), Sterkfontein (1935), Makapansgat (1948) and Gladysvale (1992).
He Lived betsween 1½ – 2mya in South Africa. ~ He is the biggest and most recent Australopithecine. – weight 68kg. He had more robust skull, jaws, and teeth. ~ He ate fruits, nuts and raw tubers- was apparently a vegetarian. ~ His Remains were found primarily in cave deposits at Swartkrans and Kromdraai in South Africa. ~ His Average brain size was about 530 cc ~ The East African Australopithecus Robustus was named as Australopithecus Boisei
Genesis of Bi pedalism.
The earliest hominin fossils discovered so far from Ethiopia and Kenya are dated 2 million years earlier (see unit 19); they show significant adaptation to bipedalism in combination with a hominin dental pattern that has distinct apelike overtones. It is therefore possible that the first hominin might have been apelike in all respects, apart from an adaptation to upright walking. If true, then bipedalism would represent the primary hominin adaptation. In this unit we will examine some of the mechanics of bipedalism, the ecological context in which it might have arisen, and the development of hypotheses that purport to account for its evolution.
The striding gait of human bipedalism involves the fluid flow of a series of actions collectively, the swing phase and the stance phase in which one leg alternates with the other. The leg in the swing phase pushes off using the power of the great toe, swings under the body in a slightly flexed position, and finally becomes extended as the foot again makes contact with the ground, first with the heel .Once the heel-strike has occurred, the leg remains extended and provides support for the body stance phase while the other leg goes through the swing phase, with the body continuing to move forward.
Figure 5.The image of the process of Bi pedalism
Features differentiate human and chimpanzee bipedalism.
First, chimpanzees are unable to extend their knee joints to produce a straight leg in the stance phase. Thus, muscular power must be exerted in order to support the body. Try standing with your knees slightly bent, and you’ll get the idea. The human knee can be “locked” into the extended position during the stance phase, thereby minimizing the amount of muscular power needed to support the body. The constantly flexed position of the chimpanzee leg also means that no toe-off and heel-strike occur in the swing phase.
Second, during each swing phase the center of gravity of the body must be shifted toward the supporting leg (otherwise one would fall over sideways). The tendency for the body to collapse toward the unsupported side is countered by contraction of the muscles (gluteal abductors) on the side of the hip that has entered the stance phase. In humans, because of the inward-sloping angle of the thigh to the knee (the valgus angle), the two feet at rest are normally placed very close to the midline of the body. Therefore, the body’s center of gravity need not be shifted very far laterally back and forth during each phase of walking. Third, the transverse and longitudinal arches of the human foot make it a propulsion-contributing lever, as compared with the grasping function of the chimpanzee foot. Modern human anatomy is a fully terrestrial adaptation, although the earliest hominins also demonstrated some arboreal adaptation. As we shall see later, these differences have implications for energetic efficiency. The suite of anatomical adaptations that underlie human bipedalism includes the following characters:Having.
- a curved lower spine.
- A shorter, broader pelvis and an angled femur, which are served by reorganized musculature.
- Lengthened lower limbs and enlarged joint surface areas.
- An extensible knee joint.
- A platform foot in which the enlarged great toe is brought in line with the other toes; and a movement of the foramen.
Figure 6.The pelvic tilt: Gluteus medius and minimus muscles link the femur (thigh bone) with the pelvis.
They contract on the side in the stance phase, preventing a collapse toward the side of the unsupported limb. Nevertheless, the pelvis tilts during walking.
It has been suggested that the endurance locomotion provided by bipedalism enabled the earliest hominins to follow in the wake of migrating herds, opportunistically scavenging the carcasses of the inexperienced young and the infirm old.
Figure 7.Driven forces for Bi pedalism
One problem arises with both these explanations: not only do stone tools that are required for cutting meat from carcasses apparently postdate hominin origins by as much as 3.5 million years, but also no indication of regular meat-eating has been found in the dentition of the earliest known hominins. In fact, evidence from microwear patterns on the surface of teeth (see unit 18) shows that hominin diets remained predominantly vegetarian until approximately 1.8 million years agoathat is, until the origin of Homo erectus. Other explanations offered for the origin of bipedalism have included the following:
- Improved predator avoidance, as the biped would be able to see further across the “open plain” than the quadruped
- Display or warning
- Shift in diet, such as seed-eating; and
- Carrying things.
3.HOMO ERECTUS (“Upright Man” )
Homo erectus means standing upright. Specimens of early Homo erectus sometimes termed as Homo Ergaster. Are known from the Turkana Basin and the upper Bed II at Olduvai Gorge at ca. 1.8–1.5Million years ago. Homo erectus lived between 500000 and 50000 years ago. Until recently, Homo erectus was considered an evolutionary ancestor of modern human beings, or Homo sapiens. Homo erectus appears to have been the first hominine capable of systematic hunting, the first to make anything resembling a home and the first to use fire. The teeth and jaws were larger in Homo habilis than Homo erectus, suggesting that habilis ate tougher food, such as vegetation.
Characteristics of Homo Erectus
- Homo erectus has more modern arm and leg proportions, smaller jaws and a more projecting nose. During this period, the climate in East Africa was becoming drier and cooler, and the landscape less forested.
- Homo erectus was a successful and mobile species and it appears that tool-use enabled it to easily extend its range and occupy different habitats.
- He lived in groups (possibly up to 100), made tools such as hand axes and definitely made regular use of fire; characteristics requiring communication. Around 412000 years ago, Homo erectus was hunting rhinos and elephants and using tools of stone, bone, wood and antler.
- He was BIPEDAL- standing about 4-5 feet tall with a larger brain (700-1250cc). he lived between 2 million and 200,000 years ago.
- He was clever as illustrated by his ability to make Acheulian tools such as the hand axe which was used as an axe, knife or even as a scraper. He was the First hominid to invent and use fire.
- Their skeletons were larger and showed that they were quite heavily muscled
- They were omnivorous like many other early hominids.
- Only had hair on their head and back like are men that we have today.
Places were Homo Erectus’fossils found.
The remains of Homo Erectus were found in Hardar, Ethiopia where the skeleton of a female ‘lucy’ were found. Other fossils were found near Nariokotone River on the north western shores of Lake Turkana by Kamoya Kimeu in 1984. Also at Olorgesaillie near Magadi, Isimila near Iringa in Tanzania and Tenerife in Algeria.
The most famous Homo Erectus fossil was found in a cave in Zhoukoudian, China and became known as Peking Man/Java man
African Homo erectus fossils thus span a considerable period of time, from ca. 1.9 to 0.7 Million Ago. Many of these fossils derive from deposits that contain lithic artifacts of the Acheulean tradition, and countless sites from this period throughout northern, eastern, and southern Africa preserve Acheulean artifacts and extensive fauna but no hominid remains (e.g., Olorgesailie). In contrast to the opportunistic flaking that appears to have been a feature of the Oldowan tradition, the Acheulean assemblages (Mode 2) are generally characterized by well-formed handaxes and cleavers, and there is evidence that a much wider landscape was being utilized by ca. 1.6Ma than had been the case before. In a number of instances, the source rocks are located many kilometers from the Acheulean archaeological sites. Controversial studies may document controlled fire by 1.4Million years ago.
An abundance of stone tools associated with Homo erectus indicates a remarkable evolution in technology. This new technology is known as the Acheulian technology, named after the town of St. Acheul, France, where some of the first finds were made. Like the Oldowan choppers, Acheulian tools were produced by percussion flaking, but they exhibit more complexity. Most characteristic of the Acheulian technology is the hand ax, a sharp, bifacially-flaked stone tool shaped like a large almond, which would have been effective for a variety of chopping and cutting tasks. Unlike Oldowan choppers, which consisted of natural cobbles with a few flakes removed, the hand ax was fashioned by removing many flakes to produce a specific form. In other words, the toolmaker had to be able to picture a specific shape in a stone. Late Acheulian tools were produced through a more refined form of percussion flaking, the baton method. In this technique, a hammer, or baton, of bone or antler was used to strike off flakes. The baton allowed for more accurate flaking and produced shallower, more delicate flakes than a hammer stone. This Acheulian technology is dated at 1.5 million years ago in Africa and it persists in Europe long after Homo erectus becomes extinct. The tools produced through this technology made Homo erectus efficient hunters, able to kill large game animals such as bear, deer, and elephant, as well as smaller game.
Major Homo erectus sites in Spain and East Africa have evidence of hunters butchering various types of animals. Thus, the Acheulian technology made possible a more effective means of subsistence, which required both cooperative and intellectual efforts. Most paleoanthropologists suggest that improvements in language and modes of communication probably began to evolve with the Homo erectus lifestyle. Undoubtedly, the increase in brain size, especially in the neo cortex, indicates a capacity for more complex learning and possibly, linguistic abilities. The capacity for communication would have aided cooperation in activities such as hunting and improvements in technological development. The Homo erectus period of hominid evolution represents a very complex adaptation to the conditions of the Pleistocene epoch.
Acheulean were early Paleolithic industries characterized by hand axes and similar types of modified stone tools. Acheulean artifact assemblages are known from ca. 1.5 to 0.2 Million years ago and span Africa, Europe, and Asia. Based originally on numerous hand axes discovered at the site of St. Acheul (France), the term Acheulean is applied to stone assemblages with large bifacially flaked, ovoid tools. In an artifact assemblage, such tools must be abundant and/or finely made for the term to apply. In Africa, where the oldest Acheulean occurrences are known, hand axes and similar tools, such as cleavers and picks, are grouped under the term bifaces. Acheulean bifaces are highly standardized compared with flaked pieces of earlier non-Acheulean industries.
Figure 8. Acheulean handaxes(Pable tools) from (a) Olduvai Gorge (Tanzania); (b) Lantian (China); (c) Combe-Grenal (France).
It is widely assumed that most Acheulean assemblages were manufactured by populations of Homo erectus. Fossils of Homo erectus, however, are only rarely associated with Acheulean tools (e.g., at Tighenif [Algeria], Olduvai, and perhaps Swartkrans (South Africa). In Africa, the oldest occurrences of the Acheulean (e.g., Konso and Olduvai middle Bed II) are in the time range of Homo erectus (e.g., Olduvai Hominid 9). But after 700Ka, they also occur at sites (e.g., Saldanha [South Africa], Ndutu [Tanzania], Bodo [Ethiopia]) yielding fossils often assigned to archaic Homo sapiens. In Europe, Acheulean assemblages first occur soon after 0.5 Million years ago. It is further assumed that these Acheulean tool makers were hunter-gatherers who ranged widely for food. In fact, little is really known about the specific behavior and ecology of these hominids—for instance, whether they hunted big game or how they used their environments. Despite the prevalence of hand axes over an enormous time span, little is known about how they were used. One study of microscopic edge wear has shown that European hand axes were sometimes employed in butchery activities, and associated flakes also showed signs of working wood, hide, and bone. At other sites (e.g., an elephant skeleton and associated lithics excavated at Olorgesailie), handaxes evidently served as the cores for sharp flakes used in butchery. Experimental studies have indicated that bifaces are excellent all-purpose tools; their widespread distribution over much of the Paleolithic appears to bear this out. Migration of Homo erectus
The major hypothesis is that as populations increased, a certain percentage migrated into new territories following game animals as they moved out of Africa (Anto . n, Leonard, and Robertson 2002). If each group moved 15 miles in each generation (25 years), then H. erectus could have migrated from Africa to Europe in 5,000 years and to China in 15,000 years. As these populations migrated across continents, they encountered different climates and environments. This movement occurred during a period known as the Pleistocene epoch, which marked the later stages of what we popularly call the Ice Ages. At intervals during this time, huge masses of ice, called glaciers, spread over the northern continents, producing colder climates in the temperate zones such as Europe and northern Asia and increased rainfall in the tropical areas, creating grasslands and new lakes. Homo erectus populations had to adapt to a wide variety of climatic and environmental conditions whether they remained in the tropics, as many did, or migrated to new areas of the world.
4.HOMO SAPIENS (“Wise Man”)
After a long period of time Homo erectus changed and became Homo sapiens. This was the highest stage in the evolution of man. It took place about 50000 BC. This evolution brought man into an end of long period struggle of man to make his life better. During this period man began to make and use more refined tools. Their Main difference with their hominid ancestors is their extreme intelligence they were the smartest hominid that ever lived with a Brain capacity of 1000-1800cc. Their Remains were found at Eliye Springs, Kanjera and Kanam in Kenya, Bodo and Omo River Valley in Ethiopia and Ngaloba in Tanzania
Characteristics of Homo Sapiens
- They lived between 200,000 and 150,000 years ago
- They improved their way of life by making a variety of flint, bone, wood and stone tools (microliths).
- They hunted, gathered and fished. Later on, they domesticated plants and animals
- Highly skilful and manipulative of the environment.
The changes which Homo sapiens underwent as a break-off from apes to modern man.
- The skull size of the early human beings became larger indicating bigger brains. For example Australopithecus, who lived between 5 and 1 million years ago, had a brain capacity of 530cm3. Homo erectus who lived later on had an improved brain capacity of between 775 and 1225cm3.
- Their jaws and teeth became more powerful compared to earlier forms indicating their use in tearing and cutting tough fibres and even the need for defence as a weapon.
- The size of the jaws and teeth became smaller.
- They developed a refined speech as compared to earlier forms.
- They were taller with less hair on their body.
- The forearms and hands underwent some changes. They developed a thumb for grasping objects. Their arms and hands became shorter, more appropriate for an upright posture.
- Their legs and feet formation also changed. Their feet and toes were smaller than earlier hominids in order to support the weight of the rest of the body while motionless or mobile. The toes were no longer in need for holding onto branches. From apes to homo sapien sapiens. Between 40 and 25 million years ago, the first apes appeared on earth. The first man (Austropithecus) appeared around 4.5 million years ago.
Sub-species of Homo sapiens
Was discovered in Zambia,hence the name Rhodesian man . They became extinct about 30,000 years ago. His Remains were found in Neander valley in Germany (1856).Other remains were found in Asia , France, Belgium, Gibraltar, Italy and former Yugoslavia.
- Rhodesian man’s Brains and skull were very similar to those of modern man.
- He had straight legs and walked with long strides.
- Neanderthals.- They Lived in caves and valleys
- He was 5 feet and 5 inches tall-much stronger, heavily built and more aggressive too.
- He Had very thick eyebrow ridges like the other hominids.
- He Made clothes from animal skins. They would scrape animal fat so they can use the skin as clothing.
- They were probably the First humans to bury their dead.
- He was most likely the most intelligent hominid other than modern humans.
- He was a nomad, gathering and hunting deer, wild pigs and wild sheep.
- Their weapons were used to impale animals and to kill them.Communication was key in hunting because they had to work as a team.
- They had the ability to use complex speech; however, their sentences were probably basic. Instead of painting on cave walls they painted their faces.
Homo sapiens Cro-Magnon.
He was almost identical to modern humans although quite muscular and taller. His Fossil remains were found in Western Europe. Their skeletons still remain in France today. They became extinct around 10,000years ago.
Characteristics of Cro-Magnon
- Had long, low skull and a wide face, a sharp, rising forehead, bushy eyebrows and prominent chins
- They had a big brain capacity and very complex thinking
- He was hunter-gatherer, painter and lived in caves
- He Knew how to make clothes
5.HOMO SAPIENS SAPIENS
They are modern day humans and they evolved about 50,000 years ago.More recent discoveries of early man include the Toumai found in Chad in 2002 dating about 6 to 7 million years ago. In 2000, another discovery was made in Baringo, Kenya (millennium man) and is believed to date 6mya. The discovery was made by Martin Pickford and Eustace Gitonga o the National Museums of Kenya. Appearance of races .It has been hypothesized modern humans, using superior technology and more efficient adaption, out competed other hominid species to quickly emerge as the only surviving hominid species on the planet. Though we feature much diversity in appearance, these differences are minor compared to our biological similarities/all human beings are quite closely related. Many of our physical differences (skin, color, hair color, etc.) are relatively recent adaptations to local environment conditions.
Characteristics of Homo sapiens sapiens.
- They have big brains and a more advanced faculty for curiosity and intelligence
- They have a large brain capacity. They do not just think, they plan ahead, make accurate forecasts, study the star and the galaxies
- They have made inventions that have made life more comfortable.
- They are Around 5 feet 6 inches tall and Walk fully upright
- They have Minimal hair on their bodies
Reasons earliest Mammals live on trees.
- There was more supply of food on trees such as insects, leaves and birds’ eggs
- Security. Animals were more secure from their enemies while up on trees Man evolved from this kind of animals Archaeological evidence points at East Africa as the cradle of mankind.
Reasons why East Africa is regarded as the place where man first evolved
Evidence from archaeologists’ show that the earliest apes first evolved around lake and rift valley areas.
- The savanna landscapes found in east Africa favored evolution while the conditions elsewhere (forests and deserts) Were unfavorable.
- The bones and weapons and tools which archaeologists are finding are proofs to this. These findings are widespread in Olduvai Gorge, Olorgesaillie, and Ngorongoro and around lakes of east Africa.
- The discovery of remains of early hominids and their material culture which form a pattern of human evolution prove this.
- Presence of important archaeological sites which are found in East Africa. In kenya;- Rusinga Island, Fort Ternan near Kericho, Kariandusi near Elementaita, Gambles cave, Olorgesaillie, Kobi For a near lake turkana, Hyrax Hill and Njoro River cave. In Tanzania; – Olduvai Gorge, Eyasi Simila, Apis Rock and Garusi In Uganda; – Nsongezi, Napak, Magosi, Paraa, Ishanga, Mweya and Nyabusora In Ethiopia; – Omo River Valley and Hadar.
- Over a long period of time, man’s ancestors lived in thick forests. Later about 15 million years ago, the forests transformed into savanna grasslands causing man’s ancestors to change both physically and mentally so as to cope with the new environment.
- The tail which no longer had any value in the savanna disappeared.
- Man became more upright as there were no more impeding vegetation as was the case of too much foliage and intertwining vegetation in the forests and also to reduce surface area onto which solar insolation had effect. These also enabled quicker movement.
- The leg and foot formation changed to enable the weight of the body to be supported and balance to be achieved while moving or at a standstill.
- Gradual use of front limbs (hands for holding objects) enabled man to make tools which made work easier. The limbs also found another role of protection from other predators. As the forests disappeared, competition for food intensified and humans had to change their earlier eating habits. Some fossil evidence clearly give distinctive evidence of the break-off point between apes and hominids.
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