Existence of life beyond Earth (Article No.1) - Beginning of life on Earth

We will talk about what will happen and how the life forms will be if they evolve outside from the planet Earth from this series of articles.
How their appearance will be?
Will they be intelligent as humans?


Before we start discussing about the life outside of Earth there is a place that we should first place our concern on. Yes,that is our home Earth. Earth is the only planet that life exists as we know for sure. So it is better to know how life evolved on Earth before we talk about the life on other planets. Isn't it?


There are 3 major theories how life originated on Earth.

1. Creation Theory
2. Panspermia Theory
3. Evolution Theory

1. Creation Myth

According to this theory the universe and  the organisms were originated from a specific act of divine creation of god. Scientifically it proves wrong but some people still believe this theory because it is related with their religion. Because this theory has no valid scientific explanation lets move to the next theory.

(Please consider that it is not my or my blog sites intention to disrespect any religion. If something like that has happened please be kind to let me know.) 

2. Panspermia Theory

It is little hard to get an idea about how the life originated from this theory,because it explains that the life has came through the universe from another place to the Earth. This theory gives an idea about how life originated on Earth but it doesn't explain how life started. Simply it says that life has originated in a place beyond Earth and the life and brought to Earth by an asteroid as microscopic organisms. This theory has spread over a wide range of ideas. The most popular one is that the aliens has cultured the life on Earth (as we culture bacteria on Agar medium) or the life originated from something they left here. However there are no valid facets to believe this theory.

3. Evolution Theory

This is the main focus in this article. To start our story we have to go 3.7 billion years back. The oldest fossil has aged that that much of time.

In the time we are talking about the Earth was a rich planet with organic compounds,minerals and oceans. Because of the atmosphere conditions of that time there were lightnings and heavy rains frequently. The ocean water was concentrated with various minerals and organic compounds,this was called as 'Primordial Soup'. Because of the lightnings and the heat there were chemical reactions on  the primordial soup and various new compounds were created and reacted with each other. These compounds subjected to create the first life form with a one cell.These single celled organisms evolve through time and gives birth to various kinds of animal species. The main two parts of the organisms evolved are the ones possess chloroplast and the ones does not. Organisms who possess chloroplasts are the early ancestors of the plants And others are the early ancestors of the animals today we see.

After another long time period those single celled organisms became multi-cellular. Unicellular cells became organized to do specific tasks as a single organism. But remember still they were limited to the water. There were animals similar to fish and the ancestors of insects lived in the every part of the ocean. According to the scientists the water level of the oceans were began to reduce and some species became extinct and some adapted to the extreme conditions in the land because of this reason.

The first ones to inherit the land was amphibians. They were not fully adapted to a life on the land,they needed water for the reproduction purpose. But the nature was not kind to them,water levels were reduced more and some little ponds like water spots were disappeared

Part of the amphibians were fully adapted to the life on land. These were the first reptiles on Earth. The mammals and the birds were gradually evolved from these reptiles. Meanwhile the plants were also evolving from water to land. 

This is a summary of a story that that happened through billions of years. The most important fact in the evolution is the 'Natural Selection'. Because of the competition among species which occur because natural selection weak ones will be defeated by the strongest and weak will die. We have to be thankful to Charles Darwin who enlighten us by finding the facts and showing the path of evolution.

We will be meeting with another article about the evolution of life in desert worlds beyond Earth.

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