Evolutionary Pathway of Sex
Asexual reproduction: due to costs of sex
Amphimixis: Fusion of gametes from two organism.
Fusing gametes are of equal size.
Anisogamy (def. male/female)
Fusing gametes are of unequal size.
Offspring produced by single mitosis: genetically identical to mother.
Normal meiosis, offspring produced by fusion of two pronuclei: may be genetically different from mother.
Unfertilized eggs develop into a new individual (can be male or female).
Facultative parthenogenesis: Female can produce offspring either sexually or asexually. Obligate parthenogenesis: organisms exclusively reproduce through asexual means.