Essay on "Origin of Life on Earth"

Essay 2 pages (645 words) Sources: 2

[EXCERPT] . . . .

The early heterotrophs are thought of as being aerobic as "the earliest cells appear in the fossil record before any evidence of oxygen in the atmosphere" (Bailey, 2007). In short, the heterotroph theory implies an evolution that could have led to the creation of the current organisms from simple molecules during the early history of our "blue" planet.

The Autotrophic Theory

The Autotrophic Theory concerning the origin of life on Earth proposes that the autotrophs (organisms that can make their own food with the help of sunlight, water, carbon dioxide, or other elements) were the first organisms that resided on Earth. A lot of information and evidence is available that supports the Autotrophic theory. A good number of members that belong to Domain Archaea are autotrophic in nature and exist in exceptionally hostile environments similar to the environments that may have been present on the early planet. Presently, such organisms occupy hot springs and thermal vents and use energy released from inorganic chemical reactions to synthesize organic molecules from inorganic components. Due to this factor, many scientists advocate and support the idea behind autotrophic hypothesis. They believe that if the ancestors of the chemoautotrophs had similar characteristics, the first organism may have been autotrophs (Bailey, 2007).

References

Bailey, E.R. (2007). Concepts in Biology (12thth ed.). N.p.: McGraw Hill. Retrieved December 30, 2012, from http://books.google.com.pk/books?id=1E853Gfo7VkC&printsec=frontcover&dq=Concepts+in+Biology'+2007+Ed.2007+Edition&hl=en&sa=X&ei=zWXgUJTdHqek4gTigoCYCw&ved=0CDgQ6AEwAA

Continue scrolling to

download full paper ⤓