Breeding population describes the part of the population likely to interbreed. An entire species can be considered a breeding population because, theoretically, all members of a species can interbreed. In population genetics, the breeding population consists only of the individuals that can potentially mate and produce viable offspring. Only breeding individuals have the potential to contribute genes to the next generation. Population genetics is the study of the behavior of genes and their alleles in populations.
Selection describes a force that determines which genes are passed on to the next generation.
Those who survive to produce offspring, which then survive to reproduce, are more fit than those who do not meet both requirements. Natural selection acts on individuals, but individuals do not evolve. Phenotype is the description of visible traits that characterize an individual or members of a population. Phenotype can reflect both an individual s genetic makeup and the effects of the environment on an individual. Genotype is the hereditary makeup of an individual.