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Name _____________________________ Period ______________ Date ___________________
Unit 6: Biodiversity & Conservation (Ch.7)
Biodiversity
• Describes the __________________ across all levels of _______________ organization
• Includes three types:
1) Genetic diversity: Differences in ___________________________________________
• Within a species, organisms have genetic differences
• In general, species with more genetic diversity have better chances of survival
2) Species diversity: Variety of _____________ in a given ________
• Easiest to visualize & ________________________________
3) Ecosystem diversity: Variety of ____________, ___________________, or communities in an area
• Ex. A seashore with rocky and sandy beaches, forested cliffs and ocean water has more biodiversity than the same area of farmland
_______________________ _____________________________ _____________________
Species Diversity – Classification
• Taxonomists classify species based on physical ________________ , ___________ makeup and ability to mate and produce ______________ offspring.
• Organisms are placed into a hierarchy of taxonomic groups:
• Domain• Kingdom• Phylum• Class• Order• Family• Genus • Species
• The more taxonomic levels two organisms have in common, the ___________________________ they are
• Taxonomic groups reflect _______________ relationships among species.
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• Below the species level, organisms may fall into________________—populations with genetically based characteristics that differ area to area.
Biodiversity Distribution
• Species are ____________ distributed among taxonomic groups.
• Even though _________ are small in size, there are ________ known species of insect than any other group.
• Scientists have identified and described ________________ species but estimate there are between ________________ species on Earth.
• Why?
• ________________________________________________
• ________________________________________________
• ________________________________________________
• Species are not evenly distributed ___________
• Latitudinal Gradient - there is an increase in species richness towards the ___________.
Benefits of Biodiversity
• _______________________ - valuable processes provided by intact ecosystems.
• Biodiversity enables services such as:
1) ___________________________________________
2) ___________________________________________
3) ___________________________________________
• High ________________ increases ____________ of communities and ecosystems, enabling them to perform services.
• Stable ecosystems are resistant and resilient.
• Resistant: Resist environmental change without ____________ function
• Resilient: Affected by change, but ______________________ and regain function
Agriculture
1) Wild strains are _____________ with related crops to transfer beneficial traits.
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• Ex. Corn that is disease resistant is cross-bred with normal corn to make a disease resistant hybrid (___________ diversity)
2) New plants are constantly being ______________ that have the potential for widespread use.
• Ex. Babassu palm used for vegetable oil (_____________ diversity)
Medicine
• Organisms contain compounds that are useful for ____________________.
• Of the 150 most prescribed drugs in the United States, _______ originated in __________.
• Ex. Yew tree, an original source of Taxol, a cancer-fighting drug
Ecotourism
__________________________________ tourism is a source of income for many nations.
Extinction
• Extinction – occurs when the _____________________of a species on the ____________ dies
• Extirpation – disappearance of a species from a particular __________ but ___________________________ globally
• Background extinctions: Naturally occurring extinctions, occurring _______ species at a time
• Mass extinctions: Events when extinction rates _____________ the normal background rate
• There have been ______ mass extinctions in Earth’s history
• Each time more than ______ of all species have gone extinct
Biodiversity at Risk
• The current extinction rate is ____________ times greater than the natural background rate.
• In 2009, 1321 species in the U.S. were classified as endangered or threatened.
• Endangered: At serious risk of _______________
• Threatened: Likely to become __________________ soon through all or part of its range
• Living Planet Index: Summarizes ______________________ trends for certain terrestrial, freshwater, and marine species
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• The Living Planet Index fell by almost 30% between 1975 and 2005.
Causes of Biodiversity Loss
4 Primary Causes of Population Decline and Species Extinction:
1) __________________
2) __________________
3) __________________
4) __________________
Habitat Loss and Change
• ___________ cause of biodiversity loss
• Organisms, ______________________________, decline in population when the habitat changes.
• Ex. Clearing forests for logging or construction
• Habitat ___________________: Patches of _____________ habitat surrounded by ________________ habitat
• In general, _________ habitat fragments can support _________________ biodiversity than smaller fragments.
• Habitat change or destruction is the primary cause of population decline in more than ________ of threatened birds and mammals.
• A few species can benefit from human induced habitat changes.
• These species tend to be ______________ and can become _______.
Ex. ___________, __________________ & _____________.
Invasive Species
• Invasive species can ____________________________ native species.
• Increase rapidly, spread and displace native species.
Pollution
• Harmful chemicals and materials that make their way into habitats can __________ people and wildlife.
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• Ex. Heavy metals, fertilizers, pesticides and _____________.
Overharvesting
• Occasionally, species can be driven toward extinction when humans _________, ____________ or ___________ a species faster than it can replenish its population.
• Poaching (____________________________) is one reason that the Siberian tiger is at risk for extinction.
• The parts from one tiger can be sold in the black market for approximately ____________.
Climate Change
• ____________ becoming a factor in biodiversity loss
• Unlike the other factors, climate change will have a _______________________ effect on biodiversity.
Protecting Biodiversity
The Endangered Species Act
• __________ that protects biodiversity, passed in 1973
• Has 3 major parts:
1) Forbids _________________ and ____________ from harming listed species and habitats
2) Forbids _____________________ made from listed species
3) Requires U.S. Fish and Wildlife Service to maintain an ________________of endangered and threatened species, and to develop a __________________ for each listed species
Benefits
• Birds which were affected by ________ are no longer endangered
• Some species are still endangered but have stopped _______________ (40% of are now stable)
Costs
• While trying to save the northern spotted owl, many __________________________because timber harvesting was prohibited in their area.
• Landowners worry that use of _________________ might be restricted to protect an endangered species.
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International Cooperation
• Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES, 1975): Bans ___________________ trade in _________________of endangered species.
• Convention on Biological Diversity (1992): International treaty to conserve biodiversity and ensure its responsible _______________________
Single-Species Approaches to Conservation
1) Captive breeding programs: Raising and breeding organisms in controlled conditions, such as ______________________________
2) Species Survival Plan (SSP): Program to save individual species, includes: ________________________________________________
• Ex. Golden Lion Tamarins
• In the early 1970’s habitat fragmentation had decreased the number to ~______.
• Now there are nearly _____ in captivity & more than _____ have been released back into the wild.
3) Cloning: Inserting _______ from an endangered species into a cultured egg cell with its nucleus removed then implanting eggs into mothers of closely ____________________
• Most scientists __________________that this will prevent biodiversity loss since it does nothing to fix the issues such as ______________.
Ecosystem and Habitat Approaches
1) “Hotspot Approach” - focuses attention on areas where the __________________________________ can be protected with the ___________________.
• A Biodiversity Hotspot is an area that both supports an especially ________________of endemic species and in rapidly ______________________.
• Endemic – found ________________ in the world.
• Hotspots have:
• At least ________ plant species found nowhere else in the world
• Already lost ______ of their habitat as a result of __________ activity
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• The 34 biodiversity hotspots are home to 50% of Earth’s plant species and 42% of terrestrial vertebrate species.
2) Economic Approaches - Many conservation efforts today attempt to balance __________________________________ with the __________________________________________:
• Debt-for-nature swap: Conservation organizations raise money to pay off a ______________________in return for improved __________________________.
• Conservation concession: Conservation organizations _________________________________________, instead of _______________________.
3) Wildlife Corridors-Connect _____________________ enabling once-isolated populations to interbreed
• Interbreeding increases ____________________.
• There is a current proposal to complete a 5000 mile long corridor in southeast Asia to rejoin pieces of tiger habitat.
• Conservation biologists hope that a planned 250-km (150 mile) long corridor in Australia will enable the endangered southern _________________ to recover from population declines
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