What Is Darwin's Theory Of Evolution By Natural Selection?

In 1959, Charles Darwin wrote “On the Origins of Species by Means of Natural Selection” and in this book he had to main points to make about evolution by natural selection. In Darwin's first main point he presented a large amount of evidence in support of the evolutionary view that species living today descended from a succession of ancestral species, this was called “descent with modification”. In his book, he proposed a mechanism for “descent with modification” and the process was then called Natural Selection. What is Darwin's theory of Evolution by Natural Selection? According to North Dakota State University, more individuals are produced by each generation that can survive. Phenotype variation exists among individuals and the variation is heritable. Those individuals with heritable traits better suited to the environment will survive. When reproductive isolation occurs new species will form. Charles Darwin has been quoted as saying, “Variation is a feature of natural populations and every population

Basically evolution is the descent of a population of organisms with some modification. How do we get descent with modification in evolution? Genetic variation which is the “raw material” or basic agent of evolutionary change. There are four agents that interact with genetic variation to produce changes in a population, including, genetic drift, gene pool, the founder effect or bottleneck effect, and gene flow. All impact Darwin's theory of evolution by natural selection. A genetic drift are when small populations become somewhat isolated from the larger populations and overtime become somewhat genetically different. In each generation the gene pool holds all the genetic variation that is available to form the next generation of offspring. The lack of diversity seen in this new colony is known as the founder effect, a second way to see a loss of genetic variation in a population is known as the bottleneck