Development of Permanent Reproductive Structures

Anatomical structures coevolved with sexual reproduction. Some of these features, such as the gametophyte of plants, are expendable: their purpose is complete after one reproductive cycle and the energy devoted to making the organ(s) is lost whether or not fertilization has occurred. By contrast, some organs last the lifetime of an individual, such as the gonads and reproductive tracts that help transport gametes within an animal’s body. Although the energy expenditure and commitment are high for the creation and maintenance of dedicated reproductive organs, the long-term benefits include reusability over multiple reproductive cycles and dedication to producing high-quality gametes as adults, which both improve overall fitness.