Evolúcii

Evolúcii, commonly rendered as evolution, is the process by which biological populations change over generations. It describes how heritable variation among individuals leads to shifts in the frequencies of traits within a population over time.

The main mechanisms are natural selection, genetic drift, mutation, gene flow, and recombination. Natural selection favors traits that improve survival or reproduction in a given environment, causing their increased representation. Genetic drift causes random fluctuations in allele frequencies, especially in small populations. Mutations introduce new genetic variation; recombination and gene flow shuffle and reintroduce alleles, generating new trait combinations and introducing variation between populations.

Over long timescales, accumulation of differences can lead to speciation, the formation of new species, often through reproductive isolation. Evidence for evolution comes from the fossil record, which documents changes in life forms over time; comparative anatomy and embryology; biogeography; and molecular data from DNA and proteins. Experimental evolution, using organisms like bacteria or fruit flies, shows adaptation under controlled conditions.

Historically, ideas about gradual change emerged long before genetics. Charles Darwin and Alfred Russel Wallace proposed natural selection as a mechanism, and the Modern Synthesis of the 20th century integrated genetics with Darwinian theory, strengthening the explanatory framework of evolution.

Evolution is a central concept in biology and a unifying framework for understanding life’s diversity, adaptation, and history. It is not goal-directed, and individuals do not evolve within a lifetime; rather, populations accumulate heritable changes across generations.