BIOL 123 Lecture Notes - Lecture 23: Epistasis, Zygote, Ovule
Document Summary
Barriers make it harder to find a mate sometimes = reduce opportunities. Timing of release of sperm (e. g. coral) Act of mating itself: die after mating, mating can be harmful, special courtship required to fertilize, ovulation, key and lock sperm. Gametic incompatibility: occurs when sperm or pollen from one species fails to penetrate and fertilize the egg or ovule of another species. Pre-zygotic reproductive barriers: aspects of genetics, behaviour, physiology, or ecology of a species that prevent sperm from one species from fertilizing eggs of another species pre-zygotic barriers reduce the likelihood that a zygote will form. Post-zygotic reproductive barriers: aspects of genetics, behaviour, physiology, or ecology of a species that prevent zygotes from successfully developing and reproducing themselves. Embryos from two different species may fail alleles may not function together. Hybrids can develop successfully sometimes = poor health (sterility = distinct species)
