Figure 1.--This diorama depicts the appearance and life style of the stone equipped hunter, 'Homo erectus'. The family is depicted living in Sangiran (an archaeological excavation site on the island of Java) about 900,000 years ago. In 1934 the anthropologist Gustav Heinrich Ralph von Koenigswald started to examine the area around Sangiran (1934). He worked there for several years. He found fosils of a species he named 'Pithecanthropus erectus' better known as Java Man. They were some of the earliest remins of early man ever found. The species has now been reclassified as 'Homo erectus'. This means that Homonid migrations out of Africa began before the devlopment of modern man. Most anthropologists, however, believe that modern humans are related to a later migratory wave out of Africa. Source: National Museum of Indonesia, Jakarta,

There is no precise date for the beginning of the Paleolithic period, but about 2 million years ago is a good rough estimate. It approximately marks the point at which homonids began to become human. Anthropolgists have found many early ape species in Africa. Most are evolutioinary dead ends. A few are in the lineage of modern man, but that line is not yet understood with percision. There were many species of Australopithecus. This is the homonoid genus that diverged from ape-like species. Archaeologists and palaeontologists generally believe that australopiths played a key role in human evolution. One of the australopith species is believed to have evolved into the Homo genus in Africa around 2 million years ago. Homo erectus was probably the first hominid to ldevelop a hunter-gatherer society--the life style of humans for most of our history. Most anthropologists identify H. erectus as the first homonid to look much like modern humans and to develop social relationships more like modern humans than the more ape-like Australopithecus species that preceeded it. The Homo specis tended to have increased cranial capacity which generally coincides with the increasingly sophisticated tools some times found with the fossils. Another important species was H. ergaster. Scientists are not entirely sure about the relationship between H. erectus and H. egaster These early fosil remains are extrenely rare and thus it is dificuklt to know for sure if they are really different species. Scientists are, however, making important strides in fitting together the relationship of these different species. A sucessor species, was also found in Africa about 1.8 million years ago, but spread all over the Old World. Erectus had a larger brain reflected in more sophisticated tools. He may also have discovered the use of fire. A key early Homo species was Homo habilis--the tool maker. The neolithic species can be dated with the appearance of H. habalis. This of course demonstrates the importance of tools is the making of modern man. H. habilis, like all the ape species in the human evolutionary line, lived in Africa. Homo sapiens or modern man originated in Africa about 0.4 million years ago. These people also spread throughout the Old World and eventually reaching the New World. One notable characteristic of H. sapiens is aack of genetic diversity, far less than most other species. It is believed that this reflects a kind of genetic bottle neck in which obnly a small number of humans survived. Some believe that this genetic bottle neck was caused by the eruption of the Toba mega-volcano and resulting in a mini-ice age about 75.000 years ago.

Rise of the Mammals (66 million years ago)

Dinosaurs dominated the earth for over 200 million years. Mammals existed, but were small, mostly subterranian, and of little imprtance. Then the Chicxulub impactor (a large asteroid or comet) about 10 to 15 kilometres in diameter struck earth. The site of the impact was unknown until recently because it is now mostly under water, near the town of Chicxulub ion the Yucatan Peninsula. The date of the impact coincides precisely with the Cretaceous–Paleogene boundary (K–Pg boundary), about 66 million years ago. It is now virtually universally recognized as the cause of the Cretaceous–Paleogene extinction event. It was a mass extinction in which 75 pecent of the plant and animal species on Earth perished. This included all non-avian dinosaurs. And it began the rise of the mammals. Small, subterraian animals were more likey to survive than large surface speciues. At the time of the impact, there were no primates.

Primates (65 million years ago)

Soon after the Chicxulub event, ancestral rodent populations were subjected to new selection pressures. It is likely that the cause of the oecitiinnwas more than likely the search for food, probably fats-moving insects in the lower forest canopy. This new group of animals emerged with five key species: 1) grasping hands, 2) depth perception, 3) large, complex brains, 4) single births and etended materna dependency, and 5) intense social bonds.

Prosimians

Prosimians are the most primitive primates. They all have the five characteristic of primates, although they are not as highly developed.. Monkeys, apes and humans all trace their evolution kutin through the prosimians. They are the only primates native to Madagascar which helps date when the island split off from Afrom frica. They are also found in Southeast Asia, but notthe New World. Modern prosimians include the lemurs, lorises, galagos, and the aye-aye of Strepsirrhini and the tarsiers of Haplorrhini. The prosimians tend to be small, nocturnal, have a claw for grooming, and a well-developed sense of smell. As with the ancestral rodent-like pcis, they have tails.

Anthropoids

Antrooids are the primary groupe that include the monkeys and apes and the five primate characteristcs are much more highly developed. Monkeys are found in both the Old nd New Worlds. They tend to be reltively smalllike the prosimins which gives them the ability to live in trees. They have arms and legs of equal lengh used in quadrupedal walking. Like prosimians, they have tails. The Old World monkeys include both arboreal and terrestial adapted species. New World species are all arboreal. Apes are only found in the Old World. They tend to be larger than the monkys with longer arms than legs. They no longr have tails. There are lesser and great apes. The lesser apes include the gibbons from Southeast Asia. They are small bodied and still adapted for arboreal life styles. The great apes are larger bodied and do not have tails. They are found in both Asia and Africa, The orangutan of Asia are the only great apes that is aboreal and the least social of the primates. Gorillas of Africa are the largest primates and because of their size the least arboreal. Chimpanzees and the relted bonobos of Africa are the modern primates most closely related to humans.

Hominids (6-7 million years ago)

Only a generation ago, antropologists believed that homomid species emerged about 3 million years. That estimate has since doubled and is now believed to have occurrd about 6-7 million years ago. The dominant view of anthropologists is that climate change drive the emergence of hominids. Some look more at dietary selction. For some time it was believed that there were two basic homomnid groups: the genus Australopithecus and Homo. Recent work is uncovering new groups.

Early groups

Anthrpologisrs have recently found evidence of additiional hominid species. While there may be more new finds, the earliest known Hominids appears to be Orrorin tugenensis gound in 2000 and nicknamed Millenial Man. Sahelanthropus was found in 2002. These finds are still being asessed, but there is some evidence of bipeadism. One of Leakey's finds was Knyathropus platyops which may have coexisted with Lucy (Australopithecus afarensis.

Australopithecus (4 million years ago)

Australopithecus is a genus of early homonids that is now extinct. This is the homonoid genus that diverged from earlier ape-like species. Australopithecus means 'southern ape'. There were many species of Australopithecus. The precise number is indispute, in part because some proposed species may be simply specimens of known species which viverged from the mean. Australopithecus afarensis is a long-lived and relatively well studies species. Remains from more than 300 individuals have been found. This is a rather klarge number for early hpomonids. They have been found in East Africa (Ethiopia, Kenya, Tanzania) and dated to 3.85-2.95 million years ago. The finds in East Africa are largely due to the Great Rift Valleg which pased north to south through these countries. A. afarensis is known to have survived for more than 900,000 years, which is over four times greater than modern humans (Homo sapiens. And the relatively large number of findings may mean that it was a prolific species. The species is perhaps best known for Lucy. A. afarensis was very similar to chimpanzees, even more so than humans. The children grew very rapidly after birth and thus reached adulthood at an earlier age than modern humans. This meant A. afarensis had a shorter period of growing up and maturation than modern humans. This meant that the young received less parental guidance and socialization. A. afarensis was esentially a bridge between apes and humans, the missing link that was so often sought after Darwin published his concept of evolution. The various Australopithecus species had a mixture of ape and human characteristics. They tended to have apelike faces, a flat nose, a projecting lower jaw. The braincase was much smaller than that of modern man. This was an estimated 500 cubic centimeters which would be about 1/3 the size of a modern human brain. Australopithecus had long, strong arms with curved fingers. This would be the characteristics needed for climbing trees which provides insights into behavior and habitat. They had small canine teeth which was more like humans than apes. They also had a body that stood on two legs and commonly regularly walked upright. These adaptations meant that they coukd live in a wide range of environments. They could live both in trees and on the fround. This was surely aa factor that enabled them to survive for about a million years over which timr climate and environments changed. Archaeologists and palaeontologists generally believe that Australopiths played a key role in human evolution. One of the australopith species is believed to have evolved into the Homo genus in Africa around 2 million years ago. A. africanus was initially regarded as ancestral to the genus Homo and some anthropologists identified Homo erectus as directly related. Anthopolgists have since found genus Homo fossils that are older than A. africanus, complicating the evolutioinary story.

Homonid Species (2 million years ago)

There is no precise date for the beginning of the Paleolithic period, but about 2 million years ago is a good rough estimate. It approximately marks the point at which homonids began to become human. Anthropolgists have found many early ape species in Africa. Most are evolutioinary dead ends. A few are in the lineage of modern man, but that line is not yet understood with percision. Homo erectus was probably the first homonid to develop a hunter-gatherer society--the life style practiced by humans for most of our history. It is unclear, however, to what extent he was a hunter as opposed to a scavenger. Hunting probably did not become primary until the neolithic era and the ability to make sophisticated tools, especially weapons. Without weapons, homonoid species would be very limited as to what they could hunt and kill. Most anthropologists identify H. erectus as the first homonid to look much like modern humans and to develop social relationships more like modern humans than the more ape-like Australopithecus species that preceeded it. The Homo species tended to have increased cranial capacity which generally coincides with the increasingly sophisticated tools some times found with the fossils. Another important species was H. ergaster. These early fosil remains are extrenely rare and thus it is dificult to know for sure if they are really different species. Scientists are, however, making important strides in fitting together the relationship of these different species. A sucessor species, Homo erectus was also found in Africa about 1.8 million years ago, but spread all over the Old World. Erectus had a larger brain reflected in more sophisticated tools. He may also have discovered the use of fire. A key early Homo species was Homo habilis--the tool maker. The neolithic species can be dated with the appearance of H. habalis. This of course demonstrates the importance of tools is the making of modern man. H. habilis, like all the ape species in the human evolutionary line, lived in Africa. Homo sapiens or modern man originated in Africa about 0.4 million years ago. These people also spread throughout the Old World and eventually reaching the New World. One notable characteristic of H. sapiens is a lack of genetic diversity, far less than most other species. It is believed that this reflects a kind of genetic bottle neck in which only a small number of humans survived. Some believe that this genetic bottle neck was caused by the eruption of the Toba mega-volcano and resulting in a mini-ice age about 75.000 years ago.

Created: 5:27 PM 4/3/2012
Last updated: 3:34 AM 7/16/2018