Theories of the Origin of Life

Once, the earth is formed then life starts appearing. There are several theories that give their own observations regarding the origin of life on earth. A few of them are discussed as follows:

1. Cosmozoic Theory (Panspermia): It was given by Richter in 1865. According to this theory, spores or seeds were the unit of life that got transferred to different planets and developed into life. These spores were known as panspermia.
2. Theory of spontaneous generation: This theory was given by Von Helmont. According to this theory, life originated abiogenetically (suddenly and spontaneously) from decaying and rotting matter like straw, mud, etc. However, the theory was strongly disapproved by Francisco Redi, Lazzaro Spallanzani, and Louis Pasteur who proved experimentally that life can originate only from pre-existing life forms. This is known as the theory of biogenesis.

The origin of life on earth is one of the mysteries to mankind. According to a common man, life is gifted by god whereas scientists believe that life has originated from non-living matter by natural means. This mystery of whether life originated from non-living matter was solved by scientists Pirie. It has been proved that the first non-cellular forms originated 3 billion years back from RNA, Protein, Polysaccharides, etc. The first cellular form of life was single cells that did not possibly originate till about 2000 million years ago. All life forms were present in the water only.

Also Read: RNA