ENV100Y5 Lecture Notes - Lecture 20: Vancouver Island Marmot, Sympatric Speciation, Great Tit
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ENV100Y5 Full Course Notes
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Session 17: evolution, biodiversity and population ecology (iii) (19-10-15) Populations can be separated in many ways: sympatric speciation = populations become reproductively isolated within the same area. Life"s diversity results from numerous speciation events: extinction = the disappearance of a species from earth, most species are extinct, most extinction from interactions with other species, mass extinctions due to environmental change. Some species are more vulnerable to extinction than others: rapid environmental change may lead to extinction, some species are resilient, ex great tit (parus major) Extinction is a natural process: extinction is irreversible, humans profoundly affect rates of extinction. Levels of ecological organization: population ecology = quantitative dynamics of populations, community ecology = interactions among species, ecosystem ecology = living and nonliving components of systems. Habitat: the environment in which an organism lives, living & non-living components, scale depends on organism, habitat selection = non-random use of available habitat, human activity conflicts with this process, e. g. fragmentation.