This is a good article. Follow the link for more information. Throughout the lives of the individuals, their genomes interact with their environments to cause variations in traits. The evolution of management theory pdf individuals with certain variants of the trait tend to survive and reproduce more than individuals with other, less successful, variants, the population evolves.
In other words, natural selection is a key process in the evolution of a population. He described natural selection as analogous to artificial selection, a process by which animals and plants with traits considered desirable by human breeders are systematically favoured for reproduction. Darwin’s writing, science had yet to develop modern theories of genetics. And in like manner as to the other parts in which there appears to exist an adaptation to an end. Yet it is impossible that this should be the true view.
Therefore action for an end is present in things which come to be and are by nature. He defined natural selection as the “principle by which each slight variation , if useful, is preserved”. The concept was simple but powerful: individuals best adapted to their environments are more likely to survive and reproduce. It struck him that as population outgrew resources, “favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species. I think it would be a most extraordinary fact if no variation ever had occurred useful to each being’s own welfare, in the same way as so many variations have occurred useful to man. This principle of preservation, I have called, for the sake of brevity, Natural Selection.
Once he had his theory, Darwin was meticulous about gathering and refining evidence before making his idea public. 1831—had proposed similar ideas, but had neither developed them nor presented them in notable scientific publications. Nature” which would do the selection. At the time, other mechanisms of evolution such as evolution by genetic drift were not yet explicitly formulated, and Darwin believed that selection was likely only part of the story: “I am convinced that Natural Selection has been the main but not exclusive means of modification. In a letter to Charles Lyell in September 1860, Darwin regretted the use of the term “Natural Selection”, preferring the term “Natural Preservation”. For Darwin and his contemporaries, natural selection was in essence synonymous with evolution by natural selection. 1869 included Spencer’s phrase as an alternative to natural selection, with credit given: “But the expression often used by Mr.
Herbert Spencer of the Survival of the Fittest is more accurate, and is sometimes equally convenient. Darwin’s, his work lay in obscurity, only being rediscovered in 1900. The synthesis grew from advances in different fields. This synthesis cemented natural selection as the foundation of evolutionary theory, where it remains today. Natural selection is here understood to act on embryonic development to change the morphology of the adult body.
However, natural selection is “blind” in the sense that changes in phenotype can give a reproductive advantage regardless of whether or not the trait is heritable. Following Darwin’s primary usage, the term is used to refer both to the evolutionary consequence of blind selection and to its mechanisms. Natural variation occurs among the individuals of any population of organisms. Some differences may improve an individual’s chances of surviving and reproducing such that its lifetime reproductive rate is increased, which means that it leaves more offspring. Even if the reproductive advantage is very slight, over many generations any advantageous heritable trait becomes dominant in the population.
This gives the appearance of purpose, but in natural selection there is no intentional choice. The concept of fitness is central to natural selection. Modern evolutionary theory defines fitness not by how long an organism lives, but by how successful it is at reproducing. If an organism lives half as long as others of its species, but has twice as many offspring surviving to adulthood, its genes become more common in the adult population of the next generation.