Evolution can be described as the change in the <u>allele</u> frequencies of a<u> gene pool </u>over time. The process of natural selection acts on specific <u>phenotypes </u>and causes a change in the frequency of the alleles that produce them. A population of organisms with similar phenotypes that interbreed is defined as a <u>species</u>. Note that<u> </u><u>species</u> evolve, not individuals.
Explanation:
Evolution is the gradual change in species over time due to selective response processes.
Natural selection of species leads to overproduction of species, variation or habitability of heritable characteristics, selection of inherited traits or phenotypes which aid the species to better suit to their environment, and to enhance and maintain the species fitness to survive and thrive in their environment.
Natural selection leads to genetic drift or shift in the gene pool to develop favorable phenotypes under random circumstances through bottleneck or founder effects.
The frequency distribution of phenotyes follows a bell curve due to either directional, stabilizing, or disruptive natural selection processes. The group or population with similar type of traits or phenotypes which can interbreed among themselves are collectively called as species.
The evolutionary changes are exhibited or observed in the species as a whole and not in an individual organism due to evolutionary processes like co-evolution, divergent and convergent evolution.