The theory of evolution

Of all the aspects of reality, the reality of the beginnings and development of life is perhaps the most intriguing of all. Wherever life came from, it began at a very primitive level. What happened then? As before mentioned, the theory is that all complex life evolved from the primitive one cell creatures that first inhabited the earth. It progressed as a result of a long process called evolution by natural selection. Charles Darwin published his book “ On the Origin of Species” in 1859 . This set out what he saw as the natural evolutionary process.

 

The beginning

The story is that life evolved thus, from mineral rich seas of early Earth, the elements that make amino acids began to cling together in long chains. Somehow, and this is the great mystery, single cell organisms began to emerge. Over time these began to mutate to form more and more developed forms of life. The primitive amino acids became RNA and then the more complex DNA.

 

Reproduction

Single cells reproduce by unraveling the DNA that exists in every cell as a copying mechanism. The DNA splits in half and finds new identical chemical partners. We are then left with two identical cells.  That is how these simple organisms reproduce. Mistakes are made however, some minor variations creep in. If these are more suited to the environment they are more likely to survive and copy themselves,  and the differentiation of life would have begun. This is the process described as evolution by natural selection.

 

Evolution

Eventually, what is called a the tree of life was formed. Our evolutionary pattern can be drawn as a diagram that comes to resemble a large leafless tree. It illustrates the progression from primitive life to the complex life forms, including us, that we see around us. From common ancestors, species animal and insect branched off and began to develop separately. The picture looks like a trunk with a few big branches grown out of it. From the big branches, representing main types variations, which became new species, would emerge over the eons. These themselves may split or branch off. The diagram looks more and more like tree with branches and twigs going up and up.

Vertebrates, invertebrates, families and species the differentiation went on and on. We are supposed to be a result of this process.

 

Natural selection

Darwin’s theory explains further variations. Over long periods of time the animals plants or organisms change form and develop according to what gives them survival advantage in their environment. For instance, where there is a lot of nutritious nuts available the birds that survive and thrive best are those that have the stronger beaks. They would then be more successful at breeding and therefore the stronger beak genes would be passed on at the expense of the weaker beak genes. If it was the only decent food source, then over time the beaks would become thicker and stronger,      ( thus survival of the fittest). This way species evolve and change over time.

 

Evidence

Evidence for the beginnings of life can only be gleaned from the fossil record. This may be incomplete, or may be misinterpreted. There can be no record of any soft bodies creatures who may have existed. Evidence for modern variations within species, due to geographic differences, can be observed.

 

Conclusion

However life started, man was supposed to have developed this way, from our primitive one cell ancestors in the primordial soup of primitive earth. Is this likely? Could this be actually where humanity came from? The mechanism of evolution by natural selection seems logical to explain minor variations. Personally I am not sure that it could be the whole story. This is one aspect of reality that is destined to remain a mystery.

Marian

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