BIOL 1001 Lecture Notes - Lecture 58: Biodiversity Hotspot, Greater Yellowstone Ecosystem, Metapopulation
6 Apr 2017
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Document Summary
Small populations are more vulnerable to extinction: results in drift & inbreeding which reduces genetic variability. Reduced fitness which results in reproduction & higher mortality: loss of genetic variation reduces ability to respond to evolutionary environmental changes, extinction vortex results. Metapopulations: organisms can move b/t patches- risk of predators, local patches of populations are part of a metapopulation where individuals move from patches, species ae being forces into metapopulation- they are(cid:374)"t adapted, patches of habitat act is islands. In metapopulations we expect populations to go extinct & become recolonized environment not suitable for island species. Island biography theory explain how to sustain population. Immigration & extinction vary with: island size & distance from mainland: large island has more immigration rate and lower emigration rate than small islands. Large islands support more species because more resources & niches. Islands closer to mainland have lower extinction rate because emigration is easier. If islands are closer there is greater migration & prevents extinction.
