BIOLOGY 1B Lecture Notes - Lecture 23: Null Hypothesis, Species Richness, Conservation Biology
Document Summary
Large scale patterns, latitude, area, distance from source. ->need to consider both richness and relative abundance. ->ecological guilds: species that perform similar function, overlap on some resources. ->as you add more species from different functional groups, then stability and productivity increase, complement each other. ->find different features and characteristics that complement each other. ->explaining why species diversity/richness increases with decrease in latitude-->near equator, topics: evolutionary age/climate stability, longer growing season/less seasonal variation. ->idea that there"s less seasonality in tropics, therefore organisms have longer period of time to be together and evolve and increase diversity. ->more time for evolution and organisms to be evolved: more energy (sun)/water/evapotranspiration. -> because of more energy, food webs can be more complex, longer, etc: spatial area hypotheses (null) ->null hypotheses, don"t imply that there"s been any evolution, just have to do with how new world is organized geographically. ->mid-domain effect-->more species ranges overlap at the tropics (pencil box analogy)
