Developmental Selection Against Developmentally Unstable Offspring and Sexual Selection

Gametes and offspring are often produced in excessive numbers, and developmental selection against early developmental stages reduces the number of offspring to what can be safely reared. Developmental selection is hypothesized to act mainly against gametes or zygotes with developmentally deviant phenotypes, and surviving offspring will hence give rise to adults with a developmentally more stable phenotype. This hypothesis is supported by observations of unsuccessful gametes or offspring often having developmentally deviant phenotypes or genetic characteristics such as chromosomal aberrations that give rise to developmental instability. Developmental selection against developmentally unstable offspring is furthermore suggested to be a direct outcome of sexual selection often being related to developmental stability. Sexual selection for developmentally stable mates is suggested to result in production of developmentally stable offspring, if a general developmental program gives rise to developmental stability both among adults and among gametes and subsequent offspring.