All living organisms are constantly involved in a struggle for existence. This was proposed by

The concept that all living organisms are constantly involved in a struggle for existence was proposed by Charles Darwin. Charles Darwin was a famous naturalist and biologist who proposed the theory of evolution by natural selection. According to Darwin, all living organisms compete with each other for limited resources such as food, water, and shelter. Those organisms that are better adapted to their environment have a greater chance of surviving and reproducing, passing on their advantageous traits to their offspring. Darwin's theory of natural selection is based on the idea that random genetic mutations occur in living organisms, leading to variations in traits. These variations can either be beneficial, detrimental, or neutral. Organisms with beneficial traits are more likely to survive and reproduce, while those with detrimental traits are less likely to survive and reproduce. Over time, the beneficial traits become more common in a population, and the detrimental traits become less common. In summary, Darwin proposed that all living organisms are constantly involved in a struggle for existence, where only the fittest survive and pass on their advantageous traits to their offspring. This concept is a cornerstone of the theory of evolution by natural selection.