Charles Darwin revolutionized biology when he introduced The Origin of Species by Means of Natural Selection in 1859. Although Wallace had also come to this revelation shortly before the publication of Origins, Darwin was This theory has been in development for a long time. Wallace amicably handed over the idea to Darwin, allowing him to become the first pioneer of evolution. Darwin was not moved to publish his discovery, which he had been collecting for several years before Wallace discovered it, because he “had never met a single [naturalist] who seemed to doubt the permanence of species” (Ridley, pp. 70). The following are the key points of Darwin's Theory of Natural Selection taken directly from the two chapters that concern it in his book Origins. In chapter III of Origins Darwin sets up his discussion of Natural Selection by establishing the struggle for existence in nature. By this he means not only an individual's need to defend himself from enemies and survive his environment, but also his ability to create living, healthy, successful offspring. The first factor concerning this struggle is the ratio of increase in any given species. Darwin explains how this struggle must occur otherwise a single species would dominate the entire earth because each of its descendants would survive. This is because each species reproduces exponentially, a pace that would soon produce astonishing numbers if left unchecked. This doesn't happen, however, because nature has a system of checks and balances. While we may not be able to detect these controls, we can see their effects from the indisputable fact that one species does not completely dominate the planet. These controls consist of enemies eating juveniles or even adults, the rigors of time or environment, and countless others. In this way birds, for example, cannot populate outside their food supplies, and the cereals they feed on are kept under control, because even if they can produce thousands of seeds only a few manage to reach maturity. Darwin goes on to show how all plants and animals compete and relate to each other in this struggle for existence. He does this by reporting various personal observations that show that the introduction of a different species of plant or animal can have a direct effect on the current survival of indigenous species and even allow other foreign species to proliferate. This leads to interspecies survival, which Darwin considers the toughest struggle of all and the one that can have the greatest effect on the evolution of a species through natural selection..