Lifescape: Seimei 40 Okunen Haruka na Tabi

Evolution (also known as biological, genetic or organic evolution) is the change in the inherited traits of a population of organisms through successive generations. This change results from interactions between processes that introduce variation into a population, and other processes that remove it. As a result, variants with particular traits become more, or less, common. A trait is a particular characteristic anatomical, biochemical or behavioural that is the result of gene?environment interaction. A key process in evolution is speciation, in which a single ancestral species splits and diversifies into multiple new species. There are several modes through which this occurs. Ultimately, all living (and extinct) species are descended from a common ancestor via a long series of speciation events. These events stretch back in a diverse "tree of life" which has grown over the 3.5 billion years during which life has existed on Earth. This is visible in anatomical, genetic and other similarities between groups of organisms, geographical distribution of related species, the fossil record and the recorded genetic changes in living organisms over many generations.