Theories of origin of life - Initial outbreak of evolution

 

• The origin of life is a unique event in the history of Universe. the universe is vast and very old almost 20 billion years old. 

• The huge cluster of Galaxy that contain star and cloud of gas and dust comprises the universe. 

• The Big Bang Theory attempt to explain to us the origin of universe. A single huge explosion is termed big bang. 

• The universe expanded and hance the temperature came down hydrogen and Helium form sometime the gas content under the gravitation and form the Galaxy of the present day universe. 

• In the solar system The Milky Way galaxy earth was supposed to be have been form about 4.5 million years back in a sereies.

• All the planets of the our solar system including earth very hot and the bearing somehow condition on earth change life originated on Earth from non living matter today or is  only knòwn place to support life.

• Origin of life on earth from non living matter about 4000 to 4200 years ago. 

• Saveral  theories have been given by the various  scientist to explain the origin 0f life. 

Theory of special creation -

• This theory  was given by Hebrew and Father sauraz. This theory states that the life was created by  some super natural power. 

• According to this story some supernatural power called  god formed living organism. living organism were formed all of sudden.  

• They have not undergone any  changes since their  formation. all these idea were strongly challenged during the 19 century. 

Cosmic panspermia theory -

• Some scientist believe that life come from outside or from other planets. 

• Early greek thinkers thought  unit of life called spores  were transferred to the different planet including earth. Panspermia is still a intresting idea for some astronomer. 

Theory of spontaneous generation or Theory of abiogenesis  -

• According to this theory  it was believed that the life came out of decaying and rotting matter. 

• This theory  was supported by anciét greek philospher. In ancient Egypt it was believed that  nile river could give rise to fish frog  crocodile.

• Von helmont demonstrated that human sweat and wheat grain could give rise to mice. 

Theory of biogenesis-

• Theory of a biogenesis was discarded by Louis Pasteur spallanzani and Reddi and supported theory of biogenesis. 

• The experiment of Louis Pasteur became famous it also known as Swan neck  flask experiment.  

• This experiment proof that the source of microorganism for fermentation is air. 

• The organism or life cannot arise spontaneously from nutrient medium. 

• The fact that new life come only from pre existing  one is the concept of bio Genesis.