BIO120H1 Lecture Notes - Lecture 9: Soltyrei, Creation Science, Genetic Drift
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BIO120H1 Full Course Notes
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Population persistence of a rare butterfly in habitat patches. A real case in conservation biology & spatial ecology. Fender"s blue butterfly depends on a rare plant. Willamette valley, oregon; in 1850, all native prairie. Now, all but 0. 5% converted to agriculture. Butterfly discovered in 1920, thought extinct by 1931, rediscovered 1989. Annual pulses of reproduction followed by heavy larval mortality. General conclusions on stability and coexistence: model populations can be driven to extinction in several ways: **but these tendencies are countered by non-equilibrial conditions, habitat patchiness, rescue-by-migration, variation in life-history strategy. Plant community ecology originally focused on discovering community types . Do find significant species associations, (e. g. , beech-maple forest, oak-hickory forest, bur-oak savannah) Mostly descriptive: experimentation is a recent addition. Early controversy: conflicting views of causes of associations. Organismal or holistic hypothesis: certain species found together because they are biologically integrated and depend on each other"s presence like tissues of an organism (typological community concept)
