Exam 3

• genetic diversity


  measures variety of different versions of same genes within a species
• species diversity


  measures number of different kinds of organisms within a community
• ecological diversity


  measures richness and complexity of a community
• fragmentation/cloning


  aspens, less genetic diversity
• species richness


  total number of species in a community
• species evenness


  relative abundance of individuals within each species
• reproductive isolation


  organisms that breed in nature and produce fertile offspring
• phylogenetic species concept


  emphasizes the branches on a taxonomic tree (cladistic relationships)
• evolutionary species concept


  defines species in terms of evolution and historic terms
• DNA sequencing and other molecular techniques

  give insight into taxonomic and evolutionary relationships
• biodiversity hotspots


  tropical rainforests and coral reefs
• Benefits of biodiversity in food

  wild plants could provide new sources of food or more genetic diversity for existing crops
• benefits for drugs and medicine

  more than half of all modern medicines contain some natural product from a wild species
• pharmaceutical companies


  actively prospect tropical countries for products
• Biopiracy


  Resources often extracted without compensation
• sharing profits


  provides an incentive to preserve native species
• ecological benefits


  Soil formation, waste disposal, air and water purification, nutrient cycling, solar energy absorption, and biogeochemical and hydrological cycles all depend on biodiversity. We do not fully understand biological communities. Loss of a seemingly insignificant species can be damaging
• What did E.O. Wilson summarize

  The human threat to wildlife with HIPPCO
• HIPPCO


  Habitat destruction, Invasive Species, Population growth, Pollution, Climate Change, Over harvesting
• habitat destruction


  biggest reason for current increase in extinction is habitat loss. conversion of forest to farmland, cities. Habitat is fragmented into small, scattered plots. Loss of habitat due to mining, dams, destructive fishing practices
• invasive species


  invasive organisms thrive in new territory where they are free of usual predators, diseases , or resources limitations that checked them in the original habitat. 80% of global invasive introduced by humans, whether accidentally or purposely. Over past 300 years approx 50,000 non-native species have become established in the US. Cost 5-12 billion/yr in US, but is a global issue
• pollution


  Pesticides, Lead, Light, Noise
• population


  human population growth and resource use/throw away culture/recycling
• Overharvesting


  Passenger pigeon, All major fish stocks expected to collapse within 50 yrs if current trends continue
• Bushmeat trade


  The trade and sale of wild animals for food, cause of extinction in animals
• ESA


  Endangered Species Act established in 1973
• endagered species


  considered in imminent danger of extinction
• threatened species


  likely to become endangered, at least locally, in the near future
• vulnerable species


  naturally rare of have been locally depleted to a level that puts them at risk
• IUCN Red List


  inventory of threatened species of protected organisms globally
• USFWS


  United states fish and wildlife services is required to propose a recovery plan detailing the rebuilding of the species to sustainable levels
• Keystone species


  species has major effect on other members of community & may be defined as one whose presence/ absence, or increase/decrease in abundance, strongly affects other species in the community, can be found anywhere on trophic pyramid. (bison, sea otters, wolves)
• indicator species


  tied to specific communities or successional stages (lichens, frogs, water breeding insects/canary in coal mine)
• Umbrella species


  require large blocks of undisturbed habitat (northern spotted owl, elephants, orangutans
• Flagship species


  attractive organisms to which people react emotionally (giant pandas, koalas, sea turtles)
• Gap analysis


  seeks out unprotected landscapes rich in species
• habitat protection


  -protect enough habitat for viability of all native species in a given region

  -manage at regional scale large enough to accommodate natural disturbances

  -Plan over a period of centuries for the evolution of the ecosystem

  -allow for human use at a level that does not result in significant ecological degradation
• primary succession


  a community begins to develop on a site previously unoccupied by living organisms, no topsoil. Ex: A lava flow creates a new land area
• pioneer species


  First species to populate an area during primary succession
• secondary succession


  an existing community is disrupted and a new one subsequently develops at the site (grass and weed)