BIOL 1001 Lecture Notes - Lecture 25: Hybrid Zone, Speciation, Species Complex
18 Jan 2016
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Document Summary
Reinforcement = wallace effect: natural selection increase reproductive isolation, reinforcement mechanisms strengthen the differences established during isolation, pre- & post-zygotic barriers are reinforcing. 0 or lower fitness for breeding between the descendant gene pool. Imperfectly separated gene pools: reinforced by pre- & post-zygotic barriers, non-zero fitness of hybrids, sometimes the point of contact is a hybrid zone, stable hybrid zone. Hybrids usually have lower fitness if the zone is stable i. e. persistent & not moving geographically: moving hybrid zone. Hybrids usually have higher fitness if the zone is moving. Hermits may ultimately disappear if this is a moving hybrid zone. Y chromosome is coming only from the male. Therefore, y chromosome can be used as mtdna c. f: y chromosome (male, mtdna (female) 100% hermit mtdna if the female was a.
