BIOL2010 Lecture Notes - Lecture 35: Andes, Species Richness, Allopatric Speciation
Document Summary
Number of species in a defined area/community. One of the strongest patterns in ecology is the latitudinal diversity gradient. Species richness higher nearer the equator than the poles. Geographic area hypothesis larger the area, the higher the number of species the most area around the equator longest line around the earth. Based off of islands, larger island, more species richness: 2. More solar energy per unit of area hits near the equator. Because there is more solar input, higher net productivity is the base of the trophic triangle higher npp, higher species richness: 3. Positive correlation between temperature and evolutionary rate. More material for natural selection and genetic drift. Shorter response time to selection pressures: biodiversity from mountain building. Species richness often high in or near mountains. Warmest color is the highest ratings in the andes mountains. Habitat gradients across altitude: tend to have the niches that are condition specific. Lots of different niches, lots of different species.
