Tuesday, 9 June 2015

NATURE GAVE US LIFE : Origins of life on earth

Now nature starts its main role to create a life on earth.Life on Earth has been changing at various rates since our common ancestor first appeared more than 3.5 billion years ago. After collision of earth with theia, earth start come its shape.Gravity pulled earth and earth comes in its spherical shape.The Earth's crust had cooled and the oceans had formed and conditions were more suitable for the formation of life. The first living organism formed from simple molecules present in the Earth's vast oceans between 3.8 and 3.5 billion years ago. This primitive life form is know as the common ancestor.As Earth began to take solid form, it had no free oxygen in its atmosphere. It was so hot that the water droplets in its atmosphere could not settle to form surface water or ice. Its first atmosphere was also so poisonous, comprised of helium and hydrogen, that nothing would have been able to survive. 



The common ancestor is the organism from which all life on Earth, living and extinct, descended .We know that life began at least 3.5 billion years ago, because that is the age of the oldest rocks with fossil evidence of life on earth.  These rocks are rare because subsequent geologic processes have reshaped the surface of our planet, often destroying older rocks while making new ones. Nonetheless, 3.5 billion year old rocks with fossils can be found in Africa and Australia.  They are usually a mix of solidified volcanic lavas and sedimentary cherts.  The fossils occur in sedimentary cherts..




Earth’s second atmosphere was formed mostly from the out gassing of such volatile compounds as water vapor, carbon monoxide, methane, ammonia, nitrogen, carbon dioxide, nitrogen, hydrochloric acid and sulfur produced by the constant volcanic eruptions that besieged the Earth. It had no free oxygen.
About 4.1 billion years ago, the Earth’s surface — or crust — began to cool and stabilize, creating the solid surface with its rocky terrain. Clouds formed as the Earth began to cool, producing enormous volumes of rainwater that formed the oceans. For the next 1.3 billion years (3.8 to 2.5 billion years ago), the Archean Period, first life began to appear and the world’s landmasses began to form. Earth’s initial life forms were bacteria, which could survive in the highly toxic atmosphere that existed during this time.


Nature nature made environment for the evolvement of life. 

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