Theories Pertaining the Origin of Life - Essay Example

The paper "Theories Pertaining to the Origin of Life" is an outstanding example of an essay on biology. There are several theories pertaining to the origin of life. Some of them include; extraterrestrial, heterotrophy, autotroph and they will form the basis of this paper.

Extraterrestrial
This is a hypothesis that tries to explain the origin of life on earth. Thus Panspermia is a hypothesis that claims life arose outside of the earth, meaning living things were transported to earth. There is a lot of evidence pertaining to this such as the evidence exhibited from the meteorite. The meteorites originating from Mars were discovered to contain complex organic molecules. There is also evidence from the exploration expedition on Mars which discovered that there was the existence of water bodies earlier on in Mars. These bodies of water were thought to have previously supported life (Enger, Ross, Bailey, 2010).
Heterotrophy
The other theories involve the development of metabolic pathways. This hypothesizes that the very first cells would have to have a way of adding new organic molecules, a process that requires energy. To obtain this energy, two ways are involved; heterotrophs capture organic molecules from their environment whereas autotrophs utilize external energy sources to make organic molecules. The heterotrophy hypothesis proposed that the first cells lived off organic molecules present in the ocean. These organisms would have been anaerobic since the atmosphere was reducing. As the organisms continued reproducing and organic molecules became depleted, the mutation could have reproduced an organism that was capable of metabolizing other material into organic material a process that would be adaptive and would promote survival (Enger, Ross, Bailey, 2010).
Autotroph
Autotroph hypothesis, on the other hand, proposes that the first organisms were autotrophs and several Achaea (primitive organisms) that live in extremely harsh environments are usually autotrophs. They usually utilize the energy that is released from inorganic chemical reactions to make organic molecules. Most probably, early competition amongst autotrophs would have led to the evolution of heterotrophic organisms and autotrophic organisms that could utilize other kinds of molecules and energy sources (Enger, Ross, Bailey, 2010).  Read More