What is Evolution?
Evolution is a scientific theory which explains the process of change that occurs in all life forms over multiple generations. These gradual changes are the result of genetic variations that occur over time, as a reaction to various factors like environmental changes, functioning of organs, etc. Human evolution is the evolutionary process that concerns the emergence of modern humans from primates.
Theories of Evolution
There are four main theories that support evolution:
a. “Theory of Inheritance of Acquired Characters” proposed by a great French naturalist, Jean Baptiste de Lamarck
b. “Theory of Natural Selection”, proposed by Charles Darwin, an English naturalist
c. “The Mutation Theory of Evolution”, proposed by Hugo de Vries, a Dutch botanist
d. “Neo-Darwinism”, which is a modified version of theory of Natural Selection and an amalgamation of Darwin’s and de Vries’ evolution theories
Evidence of Evolution
Though evolution is a topic that has been debated since the more than a century, there is abundant evidence to support this theory.
Fossil records found in the sedimentary rock deposits indicate the various changes that have occurred through the passage of time. It also proves the existence of a variety of living beings. There are similarities between closely related organisms.
Genetics play an important role in supporting evolution. Different combinations of genes make up the DNA structure which helps in understanding the difference between DNA and RNA. Particular combinations of genes are passed on from the parents to the offspring. The DNA code is the same for all living beings. Humans share almost 99% of their genetic sequence with apes like bonobos and chimpanzees. This proves that human and apes share a common ancestor. The progression of human evolution has occurred at a different rate than that of apes. Research of the DNA structure can trace the human evolution from the time of the spilt from the great apes.
Changes over Generations: The organisms that we see today did not look the same 200 years ago. These changes prove that evolution is an on-going process.
Natural Selection that ensured the extinction of various species due to their inability to adapt to the environment.
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