Final answer:
Outcrossing systems maintain genetic variation by promoting genetic diversity through the mating of individuals from different populations. This helps populations adapt to changing environmental conditions and reduces the risks of inbreeding depression. Self-pollination in plants leads to less genetic diversity compared to cross-pollination or out-crossing.
Step-by-step explanation:
Outcrossing is a breeding system that involves the mating of individuals from different populations or unrelated species. This process promotes genetic variation within a population. By introducing new genetic material, outcrossing helps to increase the diversity of alleles and genotypes, which is essential for survival and adaptation to changing environmental conditions.
For example, self-pollination in plants leads to less genetic diversity since gametes are formed from the same plant. In contrast, cross-pollination or out-crossing in plants involves the exchange of genetic material between different plants, resulting in greater genetic diversity.
Inbreeding, which involves mating between closely related individuals, can lead to inbreeding depression and reduce genetic variance. Therefore, outcrossing systems are important for maintaining genetic variation and preserving the phenotypic diversity of a population.