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Unit IV: Evolution and Biodiversity
Chapter 18: Conservation of Biodiversity
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I. Global Declines in Genetic Diversity of Crops and Livestock
Three Levels of Extinction Local Extinction-not found in parts of range/area it once inhabited but is found other places Ecological Extinction-numbers so low it can no longer fulfill niche in communities where it is found Biological Extinction-gone! Paths to Extinction 1. Endangered-so few individuals that the specie could soon become extinct over all or most of its natural range; they may soon disappear 2. Threatened-still abundant in natural range but many populations showing a decline Three Levels Ecological: Biological: gone B. Paths 1. Endangered: 2. Threatened: 3.Estimating Extinction rates: Three problems: 1) extinction takes a long time and 2) we have not even identified all species and 3) we know so little about most of these species Project rates in two ways: 1) look at rates of extinction since human record and compare to what the fossil record tells us about bird and mammal extinction rates 2) calculate species / area relationship using theory of island biogeography-90% loss of habitat causes 50 % extinction rate.
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Loss of Agricultural Biodiversity
Loss of Crop Diversity: Gene /Seed Banks: preserve genetic info and seeds in cool, low-humidity environs &tag=related;photovideo 1/colbert-mocks-glenn-becks_n_ html Loss of Livestock Diversity
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Estimating Extinction Rates
Difficult because so slow hard to document, we have not id- ed most species and little known about the ecological roles of those species or we have no reliable data to assess their status Of the estimated 10 million Use mathematical models to estimate risk Background Extinction: species disappear at low levels Mass Extinctions: many species in a short period of time.
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Global Declines in Species Diversity
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Invasive / Alien/Non-Native Species
Native Species: live in their historic range-where they have lived for thousands-millions of years Alien: Live outside historic range Trade, transport and agriculture are three of the more common routes, or “pathways,” through which invasive species arrive. Some species moved accidentally , some intentionally Asian Carp
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Kudzu
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Zebra Mussels feed by drawing water and filtering out most of the suspended microscopic plants and animals can lead to increased water clarity and a depleted food supply for other aquatic organisms, including fish. higher light penetration fosters growth of rooted aquatic plants which, although creating more habitat for small fish, may inhibit the larger, predatory fish from finding their food. Zebra mussel infestations may also promote the growth of blue- green algae, since they avoid consuming this type of algae but not others. Zebra mussels attach to the shells of native mussels in great masses, effectively smothering them
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http://www.nwf.org/What-We-Do/Protect- Wildlife/Invasive-Species/Ballast-Water.aspx
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Population, Pollution and Climate Change
Pollution: DDT Population: Bald Eagle: saved eagle but shortage of fish mean they eat baby cormorant chicks Climate Change: Cannot adapt fast enough; Polar Bear
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Overexploitation: Hunting, Fishing, Illegally killing, capturing and selling wild species
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III. Why Preserve Species?
Ecosystem Services/ Instrumental Value: Pollination, pest control, nutrient cycling, filter water, food crops, lumber, fuel wood, paper, medicine (bioprospecting), ecotourism BEES: Colony Collapse Disorder Intrinsic Value: religious and philosophical beliefs that we have a moral obligation to preserve species Instrumental value Genetic info Intrisic ethical
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It could take 5-10 million years to re- gain biodiversity.
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IV. Solutions: Protecting Wild Species-Individual Species Approach
Lacey Act: 1900/ prohibited transport of illegally harvested game animals across state lines CITES: Convention on International Trade in Endangered Species. 1973; 175 countries. Red List (threatened species)that cannot be commercially traded as live specimens or for their parts or products and restricts trade on thousands of plants and animal. Hard to enforce; much corruption. Fig , p. 236
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Endangered Species Act (ESA): 1973 US law; one of the world’s most far-reaching and controversial environmental laws. Many amendments Designed to id and protect ES USFWS and NMFS id and list plant and animal species Any decision to add or remove a species must be based on biological factors alone, not economic or political. Forbids federal agencies to carry out or fund a project that would jeopardize the a species or their habitat Can not buy or sell product made from species; can not hunt , kill, collect or injure USFWS and NMFS are suppose to prepare a plan / designate habitat to help each species recover
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IV. Solutions: Protecting Wild Species-Ecosystem Approach
Encouraging Private Land Owners Habitat Conservation Plans: allow landowners/developers to destroy habitat if they do something in exchange, i.e. relocate species or buying habitat elsewhere Safe Harbor Agreement: Landowners get financial and technical assistance to restore, improve or maintain habitat Habitat Corridors: : A is a strip of land that aids in the movement of species between disconnected areas of their natural habitat.
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Biosphere Reserves: UNESCO
Sanctuary Approach: 544 Wildlife refugees: many of which are wetland sanctuaries for migratory waterfowl or habitat for specific endangered species. Have been threatened by invasives and human activities like hunting and atv. Zoos and Aquariums: captive breeding, egg pulling, DNA analysis for mating Reconciliation Ecology: is the science of inventing, establishing and maintaining new habitats to conserve species diversity in places where people live, work or play; protecting wilderness, though necessary, is not enough to preserve biodiversity Biosphere Reserves: UNESCO
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Reintroduction of Wolves in Yellowstone
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