EVOLUTION THEORY
Evolution - is the gradual change (development) of plants and animals from a simple form to a more complex form.
Technology - is the application of scientific knowledge for practical purpose.
Environment - means the surroundings or conditions in which a person, animals or plans operate
Note:
Evolution of man is related to the improvement of life through the use of various technological innovations. Evolution of man also related to the way human being mastered his environment as he passed through different stage.
THE ORIGIN OF MAN
There are four various schools of thoughts that try to explain the origin of man. But there are two major antagonistic theories that explains about the existence of man. These theories are creation theory and evolution theory.
THEORY OF CREATION (RELIGIOUS THEORY)
This theory explains that there is a super natural power that created everything. This supernatural power is called God referring from knowledge of (Genesis 1:26) states; “And God said let’s make a man in our image after our likeness and let them have dominion over the fish of the sea and over the fowl of the air and over the cattle and over all earth and over creeping thing that creepth upon the earth’s.
EVOLUTION THEORY
Evolution theory was proposed by an English biologist naturalist and geologist best known for his contributions to the science evolution. The man is Dr Charles Darwin lived from 1809 – 1882. The theory is also known as Charles Darwin's theory or scientific theory. The theory states that man’s species has been changing gradually from lower stage to better stage due to environment.
Importance of evolution theory
Changing goes with hand by hand with improvement of method of obtaining food, shelter and clothes.
The gradual change of man is called evolution, the first man belongs to the family of primates which includes apes, gorillas, chimpanzees and monkeys.
These animals lived in the forest walking on four limbs and their bodies were covered by hairs.
Environment forced to adapt a new way of walking.
The four limbs instead of become special for tools making and using.
Four limbs become free from walking and finally started using two limbs on walking upright. This walking was known as bi-pedalism
Because of the environmental changes and diminishing forest they started to live in open grassland.
STAGES OF MAN’S EVOLUTION
There four major stages of man’s evolution which
Primates
Australopithecus Africanus
Homo-habilis
Homo erectus
Homo sapiens
Homo-sapiens sapiens
PRIMATES
These are the 1st creatures from which the modern man evaluated from man is believed to have originated form the primate family. Primate family consists of apes, gorillas, chimpanzees and monkeys.
CHARACTERISTICS OF PRIMATES
1. Primates are free dwellers in dense forest
2. They walked using four limbs
3. Their life depends on gathering fruits, roots, insects and hunting of small animals like rats, molls etc
4. Their bodies were covered fully by hairs.
5. Tools were not yet in use of their times
6. Their brain was poor to master the nature / environment.
7. They were featured by low poor mental abilities.
AUSTRALOPITHECUS FAMILY
These were the second stage of human evolution of man caused by bipedalism creature. The fossils of this phonology were discovered at Tong in South Africa by workmen in 1924. They were also discovered in Olduvai Gorge in Arusha sometimes they are known as Australopithecus Africanus. These creatures mainly lived at the early stone age. The famous creatures which belonged to this family which are zinjanthropus, homo habilis, homo erectus ad homo sapiens.
ZINJANTHROPUS
This is an example among the members of Australopithecus family. Its skull was dog up by Dr. Luis Leakey and his wife Mary Leakey of Olduvai Gorge in Arusha, northern Tanganyika. The gorge had 300 feet deep in the eastern of the rift valley.
The skull was called zinjanthropus “Man of zinj” which was the name of east Africa coast zinjanthropus lived between 1,750,000 and 1,500,000 million years ago B.C. Zinjanthropus could not make tools. It was only a tool user.
PHYSICAL CHARACTERISTICS OF ZINJANTHROPUS
1. Zinjanthropus had a heavy lower jaw because a larger molar which made it to have muscles.
2. Zinjanthropus used the molars to crush and grind its food. The larger molar made the archaeologist to call it nutcracker man.
3. Zinjanthropus had thick skull bones.
4. Zinjanthropus had small brain around 27 – 34 cubic inches.
5. Zinjanthropus had no forehead because it had a ridge of bone along the skull.
6. Zinjanthropus had much hairy body
HOMO HABILIS
This creature lived between 1,500,000 BC and 750,000BC during the period of early stone age. It was called a skillful man because it was a systematic tool maker. It was using two feet for making movements (walking). It also had skills and two hands. It was able to make tools and use them; such tool are pebbles, chopping etc. These tools were called “oldowan tools” that were used to kill on small animals like antelopes, young pig, frogs and birds. The fossils of this creature were discovered in Olduvai Gorge in Tanzania, Omo in East Rudolf of Kenya.
Homo-habilis is also known as Handy-man
PHYSICAL FEATURES OF HOMO HABILIS
1. It had two legs and hands
2. It had bigger brain nearly to 43 cubic inches. (700cc)
3. It still had hairy body but no as much as that of zinjanthropus
HOMO ERECTUS
Homo-erectus means upright man.
This is the third stage in evolution of man according to Dr. Charles Darwin. It emerged around 500,000 BC and the fossils of this creature were found in Nsongenzi, Isimila, Olduvai gorege, Olorgesaile.
Other remains of Homo-erectus have been found in Algeria, Morroco, South Africa, France (St. Acheul), Spain, India and China.
Although the fossils of Homo-erectus have been found in various places of the world, the most famous Homo-erectus skeleton is that of a young female Nick named, Lucy that was found in Ethiopia.
Homo erectus was able to use hand axes during the middle stone age and it was during this period when homo erectus discovered and made use of fire.
Homo-erectus lived during the middle stone age (Mesolithic Era)
He is believed to be the first creature to make and use Fire.
He made the tools during the middle stone age whose collective name was, Acheulian Tools.
Homo-erectus was the first Hominin to move out of Africa into Asia and Southern Europe.
PHYSICAL FEATURES O HOMO ERECTUS
1.Had a more developed forehead than homo habilis.
2.Had less hair body than that of homo habilis
3. Homo erectus walked upright by using two legs that is the reason as to why it was nicknamed as “upright man”.
4. He later evolved into Homo-Sapiens
HOMO SAPIENS
Homo sapiens existed from around 500,000 BC to 1500 BC during the late / new stone age. This is said to be the ancestor of a modern man which started to live by a process of reproduction from the earlier creation which were not yet fully human being. Homo sapiens could think and make use of various activities like hunting in groups. It made and use fire to roast food defend himself against wild animals. Man began to live a settled life in small settled communities by involving himself in some domestic of animals and cultivation of crops. This was done at the time near iron age period. Areas which show the tools and settlements of homo sapiens are Nsongezi, Sango Bay, Gilgil river and Gamble’s cave.
PHYSICAL FEATURES OF HOMO SAPIENS
1. Man had ability to walk, stand, run on two legs.
2. The brain grew bigger than that of homo erectus
3. became taller than homo erectus
4. The jaw and size of teeth became smaller
5. Man made a speech which led to the growth of language for transmitting ideas to others.
Note:
This theory of evolution state that the species had their ancestors, in this theory, Charles Darwin refused the idea of creation of God.
Guiding questions
1. What is evolution of man
2. What are the two theories that try to explain the origin of man?
3. Who and when the evolutionary theory was introduced?
4. What is Bipedalism?
5. Mention five stages in the evolution of man
6. What are the physical features of primates
7. What is the nickname of Homo-habilis
8. What is the nickname of Homo-erectus
