BIOL 121 Lecture Notes - Lecture 8: Spanish Hogfish, Character Displacement, Niche Differentiation
Document Summary
Coevolution: two ecologically interacting species exert reciprocal selection pressures on one another and the response is inherited. Reciprocal selection pressure occur between interacting species such as: Species a evolves an adaptation in response to species b. Species b evolves in response to the adaptation of species a. Chapter 55, table 55. 1--- types of species interactions. Commensalism: one benefits, the other is not harmed. Driving force behind evolution and natural selection: interspecific: niche differentiation- finches, g. is; competitive exclusion; character displacement (outcome of competition, intraspecific: exploitation compaction; interference competition. Niche: functional role of species in a community, including activities and relationships. Niche overlap: sharing of niche space by 2 or more spaces. Complete competitors cant co-exist allopatric species live in different places. How does natural selection act on competition to allow coexistence: should lead to directional selection to minimize niche overlap, character displacement (minimize overlap) Morphological character displacement to reduce predation pressure and to improve resource utilization sticklebacks: resource partitioning.
