How did thomas malthus influence Charles Darwin's theory of evolution?

By writing a book that proposed human suffering and death from starvation because the population of humans went up exponentially but the supply of food goes up arithmetically. Darwin took this idea as an insight. He figured that populations of organisms produced far more progeny then the environment could supply with resources. So a selective process would be put in place. The fitter organisms would survive and reproduce while this much less fit would lose the struggle for existence.