BIOL 1202 : Bio 1202 Notes For Test 2
Document Summary
Biochemical and genetic evidence best explained by the theory of evolution. Common use and similarities of dna, rna, amino acids, ribosomes, genetic code, Correlation of dna, proteins, etc. with relatedness of species. Prezygotic barriers impede mating or hinder fertilization if mating does occur. Postzygotic barriers prevent a hybrid zygote from developing into a variable, fertile adult. Prezygotic: habitat isolation, geographical isolation, ecological isolation, behavioral (mate choice) isolation, temporal isolation (go to bar at different times, mechanical isolation (male organ doesn"t work, gametic isolation (sperm can"t make it into the egg) Post-zygotic: reduced hybrid viability, reduced hybrid fertility, hybrid sterility (in the extreme, hybrid breakdown (reduced variability or fertility occurs in the offspring of the hybrids) The process by which new species form. Two requirements: populations (gene flow sufficiently reduced) Two main modes: allopatric vs. sympatric. Allopatric speciation (different geographical area: divergence occurs in geographic isolation. Sympatric speciation (same geological area: divergence occurs despite of lack of geographic isolation.
