Origin Of Life

Origin of life Presented by Ayesha khan Kanza saleem

The geological timescale Past life is often referred to being a part of a certain era.there are 4 eons on the geological scale

Hadean eon 4.5 to 3.8 billion years ago The hadean era did not contain life

Archean eon 3.8-2.5bllion years ago This era saw the formation of the first cells This era saw the creation of simple bacteria and plant like algae

Proterozoic eon 2.5B-544 million years ago About 1.8 billion years ago eukaryotic cells began to appear

Phanerozoic eon 544 million years ago till today In this era many life forms began to flourish

EARTH BIOSPERE AND LIFE SCIENCES Earth’s original atmosphere contained little or no molecular oxygen,which is required by current animal and advanced plant life forms The oxygen currently in our atmosphere is produced by green plant photosynthesis Human are returning carbon dioxide to the atmosphere

QURAN ON THE CREATION OF MAN The Quran tells us that the creation of man took place in gradual stages “And Allah created you from dust, then from a sperm-drop, then he made you pairs” “And We made from water every living thing... (21:31)” “He Who has made perfect everything He has created. and He began the creation of man from clay. (32:8)”

CONCLUSIONS ( 1 ) The material from which man has been created is not eternal. It was created by God. (2) Man's creation involved an evolutionary process extending over a long period of time. He was not created in a moment. (3) Man was created from an origin of his own species. It is not correct that he evolved from a species of monkeys or apes which is the theory advanced by Darwin.

) He next passed through a stage of animal life but intelligence had not yet developed in him although he moved about, ate an and drank ) He became intelligent being like able to other speak and communcate. animals. ) He became an intelligent being able to speak and communicate.

In his final stage he devised a system of life and started on the road to civilization and culture. Instead of each individual living for himself, as is the case with other and lower animals, he began to work in cooperation with others of his species evolving a system and law of life.

Scientific point of view When the earth formed some 4.6 billion years ago, it was a lifeless, inhospitable place. A billion years later it was teeming with organisms resembling blue-green algae. How did they get there? How, in short, did life begin? This long-standing question continues to generate fascinating conjectures and ingenious experiments, many of which center on the possibility that the advent of self-replicating RNA was a critical milestone on the road to life.

SPONTANEOUS GENERATION Before the mid-17th century, most people believed that God had created humankind and other higher organisms and that insects, frogs and other small creatures could arise spontaneously in mud or decaying matter.

the mid-19th century two important scientific advances set the stage for modern discussions of the origin of life In one advance Louis Pasteur discredited the concept of spontaneous generation. He offered proof that even bacteria and other microorganisms arise from parents resembling themselves. He thereby highlighted an intriguing question: How did the first generation of each species come into existence?

The second advance, the theory of natural selection, suggested an answer. According to this proposal, set forth by Charles Darwin, When the environment changes, individuals bearing traits that provide the best adaptation to the new environment meet with the greatest reproductive success.

Repeated generation after generation, natural selection could thus lead to the evolution of complex organisms from simple ones. The theory therefore implied that all current life-forms could have evolved from a single, simple progenitor -

In the late 1960s Francis Crick proposed that RNA might well have come first and established what is now called the RNA world - a world in which RNA catalyzed all the reactions necessary for a precursor of life's last common ancestor to survive and replicate

Further, contemporary organisms carry their genetic information in nucleic acids - RNA and DNA From such findings we can infer that our last common ancestor stored genetic information in nucleic acids

More recent research which is supported by Professor Jones and Professor Osborne, tends to conclude that although man has developed through an evolutionary process he branched off from other animals at a much earlier period; and during that time he developed on independent exclusive lines as compared with other animals. In other words, man did not branch off from some kind of ape, as Darwin believed, but a long time before that during the development of animal life.