Darwin's theory of natural selection was influenced by the book "an essay on principle of population" which was written by Thomas Malthus.

Thomas Malthus and the Influence on Darwin's Theory of Natural Selection
The theory of natural selection, proposed by Charles Darwin, was influenced by several factors, one of which was the work of Thomas Malthus. Here is a detailed explanation of how Malthus influenced Darwin's theory:
1. Thomas Malthus and his Population Theory:
- Thomas Malthus was an economist who proposed a theory on population growth in his book, "An Essay on the Principle of Population," published in 1798.
- Malthus argued that human populations have the potential to grow exponentially, while the resources available to support them grow linearly.
- According to Malthus, this disparity between population growth and resource availability would lead to competition for limited resources, resulting in a struggle for survival.
2. The Influence on Darwin:
- Darwin, being aware of Malthus' theory, recognized its relevance to the natural world and its implications for the survival of species.
- He saw parallels between Malthus' theory of population growth and the struggle for survival that he observed in nature.
- Darwin realized that within a population, individuals with advantageous traits would have a better chance of surviving and reproducing, while those with less favorable traits would be less likely to pass on their genes.
3. Natural Selection:
- Building upon Malthus' theory, Darwin formulated the concept of natural selection as the key mechanism driving evolution.
- According to Darwin, individuals with advantageous traits that are better suited to their environment have a higher chance of surviving and reproducing.
- Over time, these advantageous traits become more common in the population, leading to the gradual evolution of species.
4. Confirmation of Malthus' Theory:
- Darwin's theory of natural selection provided empirical evidence to support Malthus' theory of population growth.
- By observing the variations and adaptations within species, Darwin demonstrated how natural selection acts as a mechanism for population control, preventing exponential growth.
Conclusion:
Thomas Malthus' theory of population growth greatly influenced Darwin's formulation of the theory of natural selection. Malthus' ideas on the competition for limited resources and the struggle for survival provided the foundation for Darwin's understanding of how advantageous traits become more prevalent in a population over time. Darwin's theory of natural selection, in turn, provided empirical evidence for Malthus' theory of population control.