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Evolution of Man
Evolution of Man
Unbelievable but true is the miracle of life. Nobody is certain when life began, but the first fossil sea animals date back about six hundred million years ago. It was another two hundred million years later that vertebrates evolved on land shaped like amphibians, who were air–breathing fish which had begun to modify their fins into primitive legs. Today the dominant forms of terrestrial life are mammals rather than reptiles. The key to adaptation is the concept to govern the environment for survival.
Formation of Life
The formation of Life
The formation of earth dating back a billion years from a large mass as goes the Big Bang theory is really exciting. The universal forces resulted in formation of orbits in which earth and other planets revolved around the sun. After a few million years when water actually formed from the environmental gases (H2 AND O2) first forms of Life called–protoplasm appeared. The basis of life is 4 elements, viz, earth, water, wind and fire simply put, but actually C(Carbon), O(Oxygen), H(Hydrogen) and N(Nitrogen) are what were the constituents of protoplasm which came together and combined under perfect atmospheric conditions to evolve Life. Although another theory states that C, H and N were the constituents of Protoplasm with the ability to combine with O2 (oxygen) and oxidize themselves. These unicellular organisms evolved into multi–cellular organisms and aquatic animals, that is when (fish were formed). They turned into amphibians, then into dinosaurs and finally into various other species.
Mammals and their characteristics
Mammals succeeded the reptiles as the dominant form of animal life on surface of the earth because they were significantly better adapted due to limbs.Major characteristics of mammals is warm–bloodedness (maintenance of relatively high and stable body temperature) Along with warm–bloodedness goes evolution of efficient insulation in the form of hair, fur or layer of fat deposits. Also teeth for mastication and most of all mammals ceased to lay eggs instead gave birth to young ones (viviparous). This was the most efficient mode of reproduction and made the mammals take better care of their offspring. Most important the evolution of intelligent behavior came with mammals. They exhibit curiosity, adaptability, capability of learning from experiencing.
The first primates appeared about 65 million years ago–tree mammals. All primates have large brains, developed eyes and good stereoscopic and binocular vision. The sight became all important and the tendency to explore and manipulate surroundings with limbs increased. The evolution of the thumb holds greater significance since the ability to grasp tools, climb trees and defend Mammals Tools oneself from offensive wild animals originated from it. The capacity of grasping objects by foot is lost in man but the hand remains the grasping tool. Finally a number of such minor features such as claws developed into nails; collar bones developed and with 2 nipples high on the body bequeathed the man.
The primates later diversified into Prosimians, Monkeys, Apes and Man. The Gibbons, Simians and Orangutans are arboreal but Gorillas and chimpanzees are terrestrial. Man exists now with ground–living existence and with unique adaptation of his own. By being omnivorous that is able to eat anything he developed greater dietary flexibility. By living in family groups, social behavior Terrestrial Ancestor developed along with fostering culture, which took man to its ultimate mental vivacity.
Australopithecus was probably man’s first fully terrestrial ancestor. Over 4 million years ago he lived on diet of seeds and fashioned crude tools as defense against carnivorous cats because he was 4 feet tall and weighed less than 100 pounds and was found in India and Java (South East Asia).