We all wander,How we came into being?   That's, the same question our grand fathers and great grand fathers asked to themselves. But, they hadn't the answer. Now, sc

That's, the same question our grand fathers and great grand fathers asked to themselves. But, they hadn't the answer. Now, scientific research enables us to answer that question. Roughly, every single specie on this planet shares one common ancestor and for comparison, we can take a look, how humans share similar genetic composition with other organisms such as, 

1. We have similar genetic makeup with cows about 80%.

2.We do have 61% similar genetic makeup with Fruit flies.

3.And the most similarities we have with Chimpanzees about 98% similar genetic makeup. 

In this article, we are going to discuss about,

THE LAST UNIVERSAL COMMON ANCESTOR, It was not the bacterium neither the virus. It was the single celled bacterium like organism. At that time the age of earth was merely, 560 million years. It could have lived somewhat an alienated life (with which we are not so familiar ). According, to one research it was living in the dark, iron sulphur rich environment near by the hydrothermal vents. They were anaerobic, it used to make it's food by itself by using hydrogen, carbon dioxide and nitrogen gives rise to ammonia for it's use (usually organic compounds).This little microbe gives rise to the present form of complicated life. This little creature gives rise to the Archeae and Bacteria.

All the living beings have the common ancestor, this idea came after when the researchers studies the genome of 2000 modern microbes. They narrowed down to 335 genes which were common in all of these modern microbes' genome's. This term "THE LAST UNIVERSAL COMMON ANCESTOR" was being firstly, used by Carl Woese in 1990's. He gave an idea that the present day life on earth has only 3 domains;

Two prokaryotic nature ( Archeae and Bacteria).And, one Eukaryotic nature (Eucarya).All of them arises from one single celled organism.When we trace back the genetic makeup of all of the organism we got the common and similar genes, which we got through the horizontal shift of genes from the last universal common ancestor. That's how, we got to know about the LUCA.

Well there is no fossil of the LUCA . But, we do have the idea about it's composition by reversing the genetic makeup of the present day microbes. So it is suggested that it has the simplest cytoplasm, no double membrane organelles in it. But, it does posses the capability of Transcription ( A process of converting DNA into mRNA). It also had the capability of Translation(process of protein production). It had no cell wall. But it does had some distinctive features such as Nitrogen fixation  ( a process in which atmospheric nitrogen is being used to produce the organic compounds).It also had the property of doing carbon fixation ( Using the atmospheric carbon to use it to form the organic compound). It was also capable of chemiosmosis which is the capability of the cell to allow the ion transfer across it's membrane. This is the known composition of the last universal common ancestor.

LUCA is responsible for the existence of 8 billion people today. And, it is also responsible for the presence of zillions of microbes and millions of trees today. 

Charles Darwin, also gave the rough idea about LUCA in his book "The origin of species", 

                                              "Therefore, i should infer from analogy that probably all the organic beings which have ever lived on this planet have descended from some one primordial form, into which life has first breathed" 

LUCA: The last universal common ancestor.

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