BIOL-K - Biology BIOL-K 103 Lecture Notes - Lecture 3: Sympatric Speciation, Allopatric Speciation, F1 Hybrid
30 Jan 2020
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Objective 1: define and describe the biological species concept of speciation and the associated problems (knowledge) Ex: wolves and coyotes even though separate species. Objective 2: compare and contrast and give examples of pre-zygotic and post-zygotic isolating mechanisms and barriers for reproductive isolation (e. g. temporal, habitat, behavioral, mechanical, and gametic isolation; hybrid isolating mechanisms) (knowledge/comprehension) Zygote - formed by fusion of egg and sperm. Species reproduce at different times of day, season, or year preventing cross fertilization. Species are in some geographic area, but live and breed in different habitats in that area. Ex: frogs that breed in temporary ponds in woods and living near frogs that breed in permanent pond along edge of woods. Many animals species exchange a distinct series of signals before mating (visual, chemical, oral) Structural differences in reproductive organs prevent mating ex: different structural arrangement (black sage is pollinated by small bees) Molecular and chemical difference between species gametes prevents formation of a zygote.
