Human Origins in Africa

Scientists Search for Human Origins

What were the the earliest humans like? Many people have asked this question. Because there are no written records of prehistoric peoples, scientists have to piece together information about the past.

Archeologists are specially trained scientists who work like detectives to uncover the stroy of prehistoric peoples. They learn about early people by excavating and studying the traces and settlemenets. Bones might reveal what the people looked like, how tall they were , the types of food they ate,diseases they may have had, and how long they have lived. Artifacts might hint at how people dressed, what work they did, or how they worshiped.

Scientists called anthropologist study culture. From the artifacts they find at archaeological digs, they re-create a picture of early people's cultural behavior. Other scientists called paleontologists, study fossils. They use complex techniques to date ancient fossil remains & rocks. Overall, these 3 branches of science work hardly and passionately to make new discoveries about how prehistoric people lived.

** Preserving the Laetoli Footprints…**A team led by famed archaeologist Mary D. Leakey was searching for fossils of the early hominids that ranged through East Africa millions of years ago. In the summer of 1976, they began joking, tossing chunks of dried elephant dung at one another. When paleontologist Andrew Hill dropped to the ground to avoid getting hit, he noticed what seemed to be animal tracks in a layer of exposed tuff—a sedimentary rock created by deposits of volcanic ash. On closer inspection of the area, the scientists found thousands of fossilized tracks, including the footprints of elephants, giraffes, rhinoceroses and several extinct mammal species. But the most extraordinary find came two years later, when Paul I. Abell, a geochemist who had joined Leakey¿s team, found what appeared to be a human footprint at the edge of a gully eroded by the Ngarusi River.

Excavations of the Footprint Tuff— as it came to be knownin 1978 and 1979 revealed two parallel trails of hominid footprints extending some 27 meters (89 feet). The volcanic sediments were dated radio metrically to be between 3.4 million and 3.8 million years old. The discovery settled a long-standing scientific debate: the Laetoli footprints proved that early hominids were fully bipedalthey had an erect posture and walked on two feetlong before the advent of stone tool making or the expansion in size of the human brain. What is more, the track way provided information about the soft tissue of the hominids feet and the length of their stridesinformation that cannot be ascertained from fossil bones. For these reasons, the Laetoli footprints attracted a huge amount of attention from scientists and the general public. Leakey, who died in 1996, regarded the discovery as the crowning achievement of her six decades of work in East Africa.

Also, Mary Leakey and coworkers discovered fossils of Australopithecus aphaeresis at Laetoli in 1974–75, not far from where a group of hominid (of human lineage) fossils had been unearthed in 1938. The fossils found at Laetoli date to a period between 3.76 and 3.46 million years ago.
Lucy’s skeleton, named after the song " Lucy in the Sky with Diamonds", is 40 percent complete and dates to about 3.2 mya. This fossil, along with the slightly older trails of footprints found at Laetoli, Tanzania, proves that early hominids were upright bipeds when on the ground."Ardi" is a newly discovered female hominid who lived 4.4 million years ago and a million years before the famous Lucy, long studied as the earliest skeleton of a human ancestor.

The Old Stone Age Begins

The Old Stone Age spanned a vast length of time. The earlier and longer part of the Old Stone Age or Paleolithic Age, lasted from about 2.5 million to 8000 B.C. The New Stone Age or Neolithic Age started
about 8000 B.C. and ended as early as 3000 B.C. in some areas.

Homo habilis("man of skill") is the earliest known species of the genus Homo; that is, the first human species. It existed from approximately 2.2 to 1.6 million years ago in east Africa.
Only a few fossil remains have been discovered so far, but these specimens exhibit a clear trend toward larger brain size. H. habilis brains are about 30% larger than those of A. africanus. Males were much larger than females, as shown by the two skulls at far right. The male is pictured on the left. Sexual dimorphism in early Hominid species expressed itself in significant size differences.

Homo erectus appears to have evolved in Africa about 1.8 million years ago. Migrations first to Asia and then to Europe. the species became extinct sometimes less than .5 million years ago. This timing places Homo erectus between Homo habilis and the earliest appearance of Homo sapiens. The time of migration out of Africa is unknown. Most scholars agreed migration occurs about 1 million years ago but there is continue debate over how much earlier than this had begun.

Recently a Homo erectus lower jaw has been found in Georgia and said to be 1.6 million years ago. A number of important firsts were recorded during the Homo erectus’ existence.

*The first appearance of hominids outside of Africa.
*The first appearance of systematic hunting.
*Tool making and use of fire.
*First indication of extended childhood.
*Homo erectus was capable of a more complex life.
*The brain size was increased over habilis ranging between 850 and 1100 cm cube.
*Body size also increased. Reaching close to 1.8 meters in male and 1.55 meters in females.
*The cranium is long and low and somewhat flattened at the front and back.
*The cranial bone being thicker than in earlier hominids.
*The face is short but wide and the nasal aperture projected forward, suggesting the first appearance *of the typical human external nose with the nostril facing downward.
*Pronounced brow ridges are present above the orbits.
*The postcranial skeleton is similar to that of modern man but it’s robust and was clearly heavily *muscled.
*Homo erectus evidently routinely experienced heavy physical exertion.

The species to which you and all other living human beings on this planet belong is Homo sapiens. Anatomically, modern humans can generally be characterized by the lighter build of their skeletons compared to earlier humans. Modern humans also have very large brains, which vary in size from population to population and between males and females, but the average is around 1300 cc.

Neanderthal Man:
*Widespread Paleolithic People. (100,000 -40,000 Years Ago)
*Had rituals for a successful hunt.
*Buried dead. Left items in the graves showing they believed in an afterlife.
*Evidence suggests they tried to explain & control their world
*Resourceful

Cro-Magnon Man:
*Art.
*Beads, Necklaces, and Bracelets
*Flute - Suggests music
*Identical to modern humans
*Planned their hunts

Scientists are continuing to work at numerous sites in Africa. Their discoveries change our views of the still sketchy picture of human origins in Africa and of the migration of early humans out of Africa.

Bibliography:
www.britannica.c
om/EBchecked/…/Laetoli-remains
www.sciamdigital.com/index.cfm?fa
mr_sedivy.tripod.com/prehist2.html
www.stanford.edu/~harryg/protected/chp22.htm
anthropology.si.edu/HumanOrigins/ha/sap.htm

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