Select the correct answer. A population of lizards lived in an ecosystem that was prone to flooding. After many generations, most of the lizards in the population had longer legs than their ancestors, which helped them flee from floods. Which statement best explains this change?
1. The lizard genes spontaneously mutated to address the flooding threat.
2. Genetic variation among lizard limbs allowed for natural selection to occur.
3. The limbs were artificially selected because humans probably caused the flooding.
4. The lizards with longer limbs cloned themselves, ensuring survival of the species.

Natural selection is a phenomenon of evolution that is defined as the differential reproduction of the genotypes of a biological population. The classical formulation of natural selection establishes that the conditions of an environment favor or hinder, that is, they select the reproduction of living organisms according to their peculiarities. Natural selection was proposed by Darwin as a means to explain biological evolution. This explanation starts from three premises; The first of these is the trait subject to selection must be inheritable. The second holds that there must be variability of the trait between the individuals of a population. The third premise argues that the variability of the trait must lead to differences in survival or reproductive success, causing some new-onset characteristics to be extended in the population. The accumulation of these changes throughout generations would produce all evolutionary phenomena.