Biology 1001A Lecture Notes - Sexually Transmitted Infection, Subtypes Of Hiv, Garter Snake
1 May 2013
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The bird gets food (nectar) out of it. The plant gets to exchange gametes with another plant, the animal pollinating gets a food reward. Ants receive sheltered/housed by the plant and also fed by the plant, while the ants will defend the plant from other herbivores. Animals compete for sources of food or water. Plants compete for space, light, water, soil nutrients, etc. Whenever there"s two or more species who need the same resource, there is competition between them. One may benefit at the expense of the other: antagonism. Disease-causing organisms: parasites & pathogens benefit at the expense of their host individual. Any of the above can give rise to the evolutionary arms race. Adaptation by species a improves its ability to interact with species b. Selection pressure on species b to evolve counter-adaptation. E. g. garter snakes eat newts in western north america. Selection pressure on a to evolve counter-counter-adaptations. Improved equipment does not necessarily lead to improved success.
