Question

Who proposed the theory of natural selection? Mention the two principles of this theory?

Answer 1

Hint: According to the theory of natural selection, organisms can change with time due to the changes in the behavior or heritable physical traits. Changes are those that allow organisms to adapt in a better way with its environment, it will help the organism to survive and have more offspring. The theory of natural selection is supported by geology, developmental biology, paleontology, and genetic evidence.

Complete answer:
The theory of natural selection was proposed by biologist Charles Darwin. This theory was first formulated in the book of Darwin “Origin of Species" in 1859.
Darwin proposed this theory because there were limited resources in nature, only the organisms with heritable traits that are fittest for survival and can reproduce more offspring than the previous ones, this causes the traits to increase in frequency over generations.
Two principles of this theory are:
Inheritance: Most of the traits of an individual are passed or inherited from parent to the offspring, but the inheritance of traits was unknown.
Selection: Offspring organisms which have the more favorable characteristics are more likely to survive and have more offspring as compared to those individuals which have less favorable characteristics.
Offsprings are not identical; they show variations in behavior and appearance.

Additional Information:
Darwin described the theory of natural selection in comparison to artificial theory.
‘Survival of the fittest ‘describes that the individuals which are fit, have the most favorable characteristics, and best adapted to the environmental conditions can survive and reproduce.
Natural selection causes individuals to change over time.
Five steps of natural selection are:
Variation
Inheritance
Selection
Time
Adaptation
For example, Snakes and birds sometimes eating tree frogs.

Note:
The theory of natural selection played a most important role in shaping evolution. By natural selection, an organism that fits with the environment selects only those traits that will be inherited from one generation to the next with greater frequency. Through the process of natural selection, the organism adapts, and changes with the environment. Natural selection leads to speciation.