BIO152H5 Lecture Notes - Lecture 18: Mate Choice, Biological Agent
Document Summary
Lecture 18 sexual selection and male-male competition. Reproduction and evolution: mating behaviour and mate choice play a key role in determining reproductive success: Sexual dimorphism: phenotypic differences between males and females. Conspicuous behaviours: mating behaviours to attract females but can also attract predators. Conspicuous armaments: good visual proxies for fighting abilities, a harmful biological agent used as a weapon to cause death. Sexual selection: leads to exaggerated traits. Mating systems: monogamous: one male mates with one female. Care of young by both parents enhances the survival of offspring: polygamous: one individual of one sex mates with several individuals of the other. Asymmetry of sex: unequal sized gametes. Sperm: inexpensive, small, many: females invest more energy in offspring than males. Fitness limited by access to resources for eggs and young. Fitness limited by access to fertilizable gametes. Sexual dimorphism: physical differences can be apparent only during mating season or all year round. Various organs to threaten opponents: manifestations.
