BIOL 230 Lecture Notes - Lecture 2: Biogeography, Damselfly, Input Hypothesis
Document Summary
Input hypothesis: ovipositing damselflies avoid small bromeliads because they expect their larvae to have low fitness. Ultimate hypothesis: explains root causes of the effect, gives full causation. Output hypotheses: damselfly larvae die in small bromeliads because they run out of prey. Measure amount of prey biomass in small bromeliads enough to support damselfly larva: damselfly larvae die in small bromeliads cause vulnerable to terrestrial predators. Hold everything constant, except one thing you think is important (bromeliads differ in size) Include control treatment (add spider to half of treatments: damselfly larvae die in small bromeliads cause small bromeliads dry out. Small bromeliads -> high risk of drought -> observations. Q1: what determines the number of species: global scale, regional (biogeographic) scale, landscape (island) scale, local scale. Scale of an ecological community: a single habitat. Small enough so that all species could potentially interact with each other (at least over a few generations)
