(N/A) Variation arises in sexually reproducing populations due to processes like crossing over during meiosis,random fusion of gametes,and genetic recombination.
Factors such as the random arrangement of bivalents,hybridization,exposure to mutagens,and genetic drift also contribute to the creation of variation,which is essentially random and directionless.
However,natural selection acts as a filter where the environment determines which variations are advantageous for survival and reproduction.
Because the environment imposes specific pressures,natural selection is directional,favoring traits that enhance adaptation to those specific conditions.
Consequently,over time,populations become better adapted to their environment,increasing their overall fitness.