Evolution (in the study of biology) means a change in inherited traits of a population of organisms from one generation to the next. These changes are caused by a combination of three main processes: variation, reproduction, and selection. The properties on which the evolution is carried by genes that are passed on to offspring of a mortal and a variable in a population. When organisms reproduce, their offspring will have new properties. New properties can be obtained from the changes due to mutations in the gene or gene transfer between populations and between species. In species that reproduce sexually, new combinations of genes are also produced by genetic recombination, which can increase variation between organisms. Evolution occurs when these heritable differences become more common or rare in a population.
Evolution is driven by two main mechanisms, namely natural selection and genetic drift. Natural selection is a process that causes terwaris properties that are useful for the survival and reproduction of organisms become more common in a population - and vice versa, the nature of the harm to be further reduced. This occurs because individuals with advantageous traits are more likely to reproduce large, so that more individuals in the next generation that inherits beneficial properties of this. After several generations, adaptations occur through a combination of small changes in the nature of the occur continuously, random natural selection.
Meanwhile, genetic drift (English: Genetic Drift) is an independent process that produces random changes in the frequency properties of a population. Genetic drift is produced by probability whether a trait is inherited as an individual will survive and reproduce.
Although the changes generated by drift and natural selection is small, these changes will accumulate and lead to substantial changes in the organism. This process culminated in producing new species. And in fact, the similarities between organisms with other organisms mensugestikan that all the species that we know originated from a common ancestor through a process that occurs slowly diverging this.
Documentation of facts made by the branch of the evolutionary biology called evolutionary biology. This branch also develop and test theories that explain the causes of evolution. Study of the fossil record and the diversity of biological organisms living has convinced scientists in the mid-19th century that species change over time. However, the mechanisms that drive these changes remained unclear until the publication in 1859 by Charles Darwin, On the Origin of Species, which describes in detail the theory of evolution by natural selection. Darwin's work was soon followed by a reception with the theory of evolution in the scientific community. In 1930, Darwin's theory of natural selection combined with the theory of Mendelian inheritance, shaping the modern evolutionary synthesis, that connects the units of evolution (genes) with the mechanism of evolution (natural selection). The explanatory power and predictive theory encourages continuous research raises new questions, in which it has become a central tenet of modern biology that gives a more thorough explanation of biodiversity in the world.
Although the theory of evolution has always been associated with Charles Darwin, but it actually has roots in evolutionary biology since the time of Aristotle. However, Darwin was the first scientist who coined the theory of evolution that has been widely proven scientific testing established face. Until now, Darwin's theory of evolution by natural selection is considered by the majority of the scientific community as the best theory to explain the evolution of events.