1. Protection of Gametes:
- Internal fertilization occurs within the female's body, providing protection for the eggs and sperm from environmental factors such as desiccation, mechanical damage, and predation.
2. Reduced Gamete Production:
- With internal fertilization, fewer gametes are needed compared to external fertilization. The male gametes (sperm) can be delivered directly to the eggs, increasing the chances of fertilization and reducing the waste of gametes.
3. Sperm Competition Reduction:
- In internal fertilization, the female has more control over which sperm fertilizes the eggs. This allows for the selection of sperm based on quality, reducing sperm competition and increasing the likelihood of fertilization by the most viable sperm.
4. Development of Specialized Structures:
- Internal fertilization has led to the evolution of specialized structures in many species. These structures, such as the male intromittent organ (e.g., penis) and the female reproductive tract (e.g., vagina and uterus), facilitate the transfer of sperm and provide a suitable environment for fertilization and development.
5. Gestation and Maternal Care:
- Internal fertilization allows for the retention of fertilized eggs within the female's body, leading to the development of gestation periods and maternal care. This provides nourishment, protection, and a controlled environment for the developing embryos, increasing their chances of survival.
6. Genetic Diversity and Inbreeding Avoidance:
- Internal fertilization enables controlled mating, reducing the chances of inbreeding and increasing genetic diversity within the population. This can contribute to the long-term survival and adaptability of the species.
Overall, internal fertilization offers several advantages over external fertilization, including protection of gametes, reduced gamete production, decreased sperm competition, development of specialized structures, gestation and maternal care, and management of genetic diversity.