BIOL 203 Lecture Notes - Lecture 20: Garter Snake, Tetrodotoxin, Coevolution
Document Summary
Huffaker"s mite experiments to examine predator-prey dynamics: oranges and rubber balls, altered the ef ciency of the predator in the two different experiments. Predators and prey exert selection pressures on each other: coevolution. Describes process of reciprocal evolutionary change in two or more interacting species: often describer predators and prey as engaged in a coevolutionary arms race. Toxic newts: rough-skinned newts contain enough tetrodotoxin in their skin to kill 25,000 mice, predation pressure from the garter snake. A predator that is resistant to the ttx toxin. Not all snakes have equal amounts of resistance: ones exposed to the newts have higher resistance. Predators can also have nonlethal effects: to avoid predation, prey individuals may change their behavior. Produce foraging time: non-consumptive effects of predators. May y nymphs reduce feeding activity in presence of predators. Insects which feed inside their hosts while they are alive, but eventually the host: herbivores. Can be classi ed as predators, grazers, and parasites: detritivores.
