True islands do limit dispersal but things like mountain tops dont as much

True islands do limit dispersal but things like

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True islands do limit dispersal but things like mountain tops don’t as much Barriers to dispersal can be sorted into three generalized groups oCorridors are routes that virtually all members of a taxon can cross Similar to the patches of habitat at either end, species in the regions they connect tend to be similar oFilters selectively prevent some species from crossing but others to come through group of species on one side of a filter tends to be a subset of the species on the other side like how deers can travel through mountains but a squirrel wouldn’t oSweepstakes routesare habitats that are nearly impossible for most species to cross except during rare and unpredictable circumstances lizards clinging onto rafts of vegetation on water during a hurricane to travel for a dispersal to be considered successful a species has to establish a viable population after arriving in a new area oso several individuals have to arrive together when a matrix between habitat patches is inhospitable, this can only happen by a number of individuals jumping over the barrier all at once o“jump dispersal” oDoesn’t always happen with corridors, can diffuse more slowly Diffusion: oCamelid family originated in north America but then migrated west to Siberia and dispersed across Asia into Africa and later from north America into
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panama making a bunch of different species o“secular migration” When compared to mainlands, islands have fewer species per unit area and asteeper species-area curve than mainlands Species richness increases with areas on mainlands oPopulations are less likely to go extinct in larger areas oAlso an increase in habitat diversity oAlso it is easier to recolonize a mainland because there are less barriers to cross When a mainland ant population declines, the area may be more easily recolonized by nearby individuals often before the dwindling population goes extinct….the rescue effect Species area curve vary with scale, evolution can change slope of the curve Island biogeography can be used in conservation biology oSave large pieces because less extinction or small pieces for more habitat diversity oNick Haddad, rescue systems like corridors between reserves could prevent extinction Had control corridors that led nowhereCorridors increased species richness in reserves Historical Biogeography: Western Kansas: duck-billed dinosaur Claosaurus agilis Cretoxyrhina mantelli: shark resembling today’s great white oThey were swimming around Kansas 90 million years ago oThis is caused by large scale climatic changes and plate tectonics Planet’s interior is partially molten rock oFloating on top of this are about 14 relatively thin, solid tectonic plates These are the continents and ocean floor Intense heat of Earth’s core sets up currents in the molten rock that very slowly move the plates on top (millimeters per year)
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