Zmienność jako podstawowe prawo przyrody

Abstract

Biological evolution is the change over time in one or more inherited traits found in populations of organisms. Two processes are generally distinguished as common causes of evolution. One is natural selection, a process in which there is differential survival and reproduction of organisms that differ in one or more inherited traits. Another cause is genetic drift, a process in which there are random changes to the proportions of two or more inherited traits within a population. An individual organism’s phenotype results from both its genotype and the influence from the environment it has lived in. A substantial part of the variation in phenotypes in a population is caused by the differences between their genotypes. Variation disappears when a new allele reaches the point of fixation – when it either disappears from the population or replaces the ancestral allele entirely. Speciation stretches back over 3.5 billion years, during which life has existed on earth. It is thought to have occurred in multiple ways, such as slowly, steadily and gradually over time, or rapidly from one long static state to another. Evolution has led to the diversification of all living organisms, which are described by Charles Darwin as “endless forms most beautiful and most wonderful”.