Evolution and Natural Selection

Introduction

The definition of evolution is to unfold, unroll, or reveal hidden potentials. An orderly transition from one situation to another is what is meant by evolution. The concept of biology and evolution was introduced after Charles Darwin. He published the book name Origin of Species in 1859. However, he correctly identified the important concepts, like adaptation by natural selection with modification. The former broadly refers to the fact that evolution has taken place and resulted in modern-day species being distinct from their ancestors. The evolutionary process known as natural selection explains how the traits of animals and their environments complement or fit together. This article will explain natural selection and evolution.

What Is Biological Evolution?

Biological evolution is the study of the history of life forms on the Earth. Life's origin is considered a unique event in the history of the universe. The universe is old and vast and almost 20 billion years old. According to the big bang theory, there was a singular huge explosion in which the universe expanded, and hence the temperature came down. The other substance, such as hydrogen and helium, are formed later. According to theory, Earth was created roughly 4.5 billion years ago. There are many ancient theories for the origin of life, such as the theory of special creation based on Hindu mythology. It explained that the world was created by God Brahma and the first man was Manu, and the first woman was Shraddha. According to this theory, life has not changed ever since its origin. Another theory was the spontaneous generation which is supported by the ancient Greek philosopher like Thales. According to this theory, life originated from non-living things or decaying and rotting matter, like straw or mud, etc, spontaneously.

Evolution is a slow or continuous process, and it has three types. The following are the types of evolution:

• Chemical Evolution - The Earth originated about 4.6 billion years ago. Chemical evolution explains the origin of early organic compounds. Early Earth had free atoms of all those elements that are vital for the formation of protoplasm (living part of the cell). The lightest items like carbon, hydrogen, nitrogen, and oxygen form the primitive atmosphere. Hydrogen was the most abundant of all of them.

• Biological Evolution - Biological evolution explains the origin of the first living cell, the protocell (proto means first). The protocell is a cluster of proteins formed by the composition of nucleic acid and protein. Nucleoprotein had the property of self-duplication. Nucleoproteins were the first sign of life. The protocell represented the beginning of life.

• Organic Evolution - Organic evolution states descent with modification. Despite the fact that life first evolved chemically on the early planet, it was eventually superseded by organic evolution. But in the present day, complex organisms have evolved from the earlier simpler organism through alterations that have been made over millions of years in a tiny but steady manner. In organic evolution, the organism develops structures and modifies them, by which they become more adaptive in its changing environment.

What Is Natural Selection?

Charles Robert Darwin proposed the theory of natural selection. Darwin later explained this theory. Darwin explained that natural selection as Fitness is the final outcome of one's capacity for adaptation and natural selection.

The main feature of the theory of natural selection is as follows:

• Overproduction - All organisms can produce an enormous number of offspring. Organisms multiply in the geometric ratio, such as plants producing thousands of seeds or insects laying hundreds of eggs.

• Struggle For Existence - Everybody competes with other people who are similar to them in the struggle for existence with other species for a basic necessity like space, shelter, or food. It is called the struggle for existence, and it continues for the whole life from birth to its natural death.

• Variation - Except the identical twins, no two individuals are similar, and their requirements are also not the same. It implies that people differ from one another. Variations are the name for these variations. This variation leads some individuals or the population of microbes to be better adjusted toward the surroundings than others. According to Darwin, the adaptive ability is inherited. It has a genetic basis. It means the features of parents are seen in the children.

• Survival Of The Fittest(Natural Selection) - Only members who possess useful variation survive the struggle for survival, which means nature selects fit individuals. This was called natural selection. The individual with the most favorable adaptation can lead the most successful life.

• Origin Of New Species - Darwin explained that inherited characteristics are transmitted to the next generation. So children become different from their ancestors. The next-generation process of natural selection repeats after many generations of new species are formed.

How Evolution and Natural Selection Are Related?

In a true sense, evolution by natural selection would have begun when the cellular form of life, with the differences in metabolic (all life processes which are essential for life) capability, originated on Earth. Different species of microbes divide fast and can multiply and become millions of individuals within hours. On the other hand, when the medium is changed, the population of microbes can survive under the new condition, and other populations of microbes can not survive. Here it shows that the fitness of the former population is better than other populations of microbes. Fitness is the final outcome of one's capacity for adaptation and natural selection.

The following are the facts by which evolution and natural selection are related:

• The two key concepts of Darwin's theory of evolution are branching descent and natural selection.

• Over time, it has been proved by evidence that evolution is a consequence of the process called natural selection.

• Nature selects the fittest individual.

• Those who fit better in an environment leave more offspring than others. These, therefore, will survive more and hence are selected by nature.

Conclusion

The study of the history of life forms on the Earth is called evolutionary biology. The origin of life on Earth takes place through the process of evolution. The origin of life is explained by Darwin's ideas of organic evolution by natural selection. It is generally believed that variation in a population result in variable fitness. Evolution is a slow but continuous process that never stops. Also, evolution is irreversible. Natural selection is defined as the selection of the fittest. Evolution and natural selection are related.