BIO 282 Lecture 11: Lecture 11
Document Summary
Diversity increase from the poles to the equator: dan janzen proposed that speciation occurs more often in the topics because tropical species mutate faster. True or false: he is looking more at the niche. Location does not determine the reason why the tropics for example have higher productivity of species. Need to come up with a hypothesis that has to do with speciation. Specialist vs generalist: dan"s hypothesis , narrow physiological tolerance with no overlap-increased costs to dispersal over a climate gradient-low gene flow-high allopathic variation, broad physiological tolerance with overlap-reduced costs to dispersal over a climate gradient-high gene flow-low allopathic variation. Tropical species on land seem to be specialists: a more specialized species should occur over a narrower range of altitudes or latitudes. True or false: specialist has a lower range in thermal niche, low gene flow, narrower range of conditions that can be tolerated. Generalists are found over a large range of conditions unlike specialists.
