BIOA01H3 Lecture Notes - Lecture 10: Sympatry, Allopatric Speciation, Zygote

• School: UTSC
• Department: Biological Sciences
• Course: BIOA01H3
• Professor: Mark Fitzpatrick

Document Summary

Number of living species may be as great as 100 million. First living forms (species) observed 3. 8 billion years ago. 99% of all species that have existed on earth are now extinct. When gene flow is reduced between populations, they may then diverge genetically as a. Genetic divergence may eventually lead to . Creates two or more distinct species from a single ancestral group result of mutation, natural selection, and genetic drift. Occurs when individuals from different populations do mate, but the hybrid offspring produced have low fitness and do not survive or produce offspring reproduce asexually. Isolation prior to mating prior to the zygote. Sexual selection - females only attracted to same species. Male genitalia fit into female genitalia like a lock and key". Genetic isolation happens when population become physically separated. Physical isolation occurs by dispersal or vicariance. Occurs when a physical barrier splits a widespread population into subgroups.