Chapters 23 and 24

23- extinction: disappearance of a species from all or part of it’s

geographical range.- More than 99% have become extinct- Mass extinctions (been 5)

- Biodiversity: variety of species.- Habitat destruction: disturbing part of an ecosystem, ex: cutting

down trees.- Humans number 1 contributor (with 50% being commercial

harvesting)- Invasive species: non native species, introduced usually by

humans

Deforestation- Loss of biodiversity- ½ of all rainforests are gone- Growing populations huge factor- Mostly in developing nations- 100’s to 1000’s of years to regenerateAquatic destruction- Coral reefs and wetlands are number one areas- Pollution and overfishing large causes- Draining for water and development another huge cause

Everglades- In Florida- Prime real-estate, being drained and blocked off- Over half of all wetlands in the US have been lostAral Sea- We covered already in detailBiodiversity- Humans benefit from high biodiversity, so why are we

destroying it- Directly threatens human health by destroying.

GMO’s: genetically altered plants (by humans)- Good and bad- Loss of biodiversity- Good for creating new and better food sources for humans- Creates draught and pest resistant plants- Bad, when a disease or pest strikes, wipes everything outMedicines- Natural chemicals for medicine- 40% of all medicines used comes from plants- Unclear as to how many cures can still be found- Lose the plants, lose the curesWilderness- Area where the ecosystem is relatively untouched.

Gene bank: secure place where seeds, plants, and genetic material are kept.ESA: endangered species act: 1973, requires a list of all species in the US that are considered in danger.- Handled by the USFWS- Threatened species may not be caught or killed- May not be disturbed- Products made from them may not be bught or sold.- Gov. can not construct any project in their habitat- Hard to enforce

24Conservation: strategy to reduce the use of resources through decreased demand and increased efficiency.- Humans waste more than any thing else- Energy conservation one way- Reduce, reuse, and recycleRecycling: using waste materials to produce new itemsReduce: use lessRe-use: change from one form to another useful form-you should know examples of eachPreserve: area of land or water set aside for the protection of the ecosystem in that area.- Only 19% of the worlds ecosystems are preserved.