Ecosystem_Diversity - Ecosystem Diversity Ecosystem...

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Unformatted text preview: Ecosystem Diversity Ecosystem Biodiversity Biodiversity • The variety of life on Earth • Genetic diversity within a species • Differences in habitats (biomes) • Different kinds of species • Distribution of species depends upon the adaptations of organisms Biodiversity Biodiversity • Distribution of species depends upon tolerance limits to biotic and abiotic factors Biological Indicators Biological • Species whose presence indicates a certain environmental parameter is present in an ecosystem • Ex. Mayfly, stonefly, & caddis fly larvae indicate high water quality (indicate lack of water pollution), cattails in everglades indicate high phosphate levels (indicate water pollution) • Amphibians are an important indicator species Natural Selection Natural • Mechanism that drives evolution • Organisms most suited to an environment (in the middle of the range of tolerance) survive to reproduce and pass on their genetic traits • Evolution is a change in the gene frequency within a population – therefore • Individuals cannot evolve – only a population Natural Selection Natural Effects of Natural Selection Effects • Adaptation – if an organism has the genetic trait to survive – it is likely to reproduce and pass on its genes – this leads to evolution. • Migration – populations survive by moving to another area with factors within their range of tolerance • Extinction – failing the first two possibilities – extinction is inevitable Species Survival Species • Vulnerable species • • • • • • Narrow distribution Small population Limited genetic variation Small number of offspring Long generation time Limited ability to migrate • Most likely to go extinct Species Survival Species • Adaptive species • • • • • • • Wide distribution Large population High degree of genetic variation Small size Large number of offspring Short generation time Ability to migrate • More likely to adapt and evolve Evolution Evolution • Reproductive isolation • Two populations of the same species that are separated and do not interbreed • Different selective pressures lead to different species Artic Fox Gray Fox Diversity Importance Diversity • Organisms perform services in their habitat – these are called Ecosystem Services • Purify air, purify water, recycle nutrients, pollinate plants, etc…. • Reduction of biodiversity potentially harms ecosystem services. ...
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This note was uploaded on 12/29/2010 for the course ENGR 514 taught by Professor Snitter during the Fall '10 term at Oregon Tech.

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