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Plant and Animal Extinction Plant and Animal Extinction Chapter 15Chapter 15

How important is How important is ppbiodiversity?biodiversity?

Earth’s BiodiversityEarth’s Biodiversity

Biologist estimate that there have been over 500 Biologist estimate that there have been over 500 million species since life began on earth 3.5 million species since life began on earth 3.5 billion years agobillion years agoIt is estimated that from 30 million to 80 million It is estimated that from 30 million to 80 million species are alive today. One half to two thirds of species are alive today. One half to two thirds of these are found in the topical forest these are found in the topical forest Only 1.4 Only 1.4 million have been identifiedmillion have been identifiedScientist estimate that 40 to 100 species go extinct Scientist estimate that 40 to 100 species go extinct every day mostly due to human activityevery day mostly due to human activity

How Do Animals and Plants Enrich How Do Animals and Plants Enrich Our Lives ?Our Lives ?

RecreationRecreationBeautyBeautyInspiration and solitudeInspiration and solitudeAntibiotics antiAntibiotics anti--cancer drugs heart medicinecancer drugs heart medicineAntibiotics, antiAntibiotics, anti--cancer drugs, heart medicinecancer drugs, heart medicineEconomic benefits Economic benefits ––hunters, anglers birders, river hunters, anglers birders, river runners etc.runners etc.EcotourismEcotourismGenesGenesServicesServices

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Why Worry About Extinction??Why Worry About Extinction??

Many species may be useful to us (food and Many species may be useful to us (food and medicine).medicine).Certain species play key roles in the Certain species play key roles in the ecosystem that we utilizeecosystem that we utilizeMost people find nature beautiful, Most people find nature beautiful, monocultures are disturbingly sterilemonocultures are disturbingly sterile

Do plants and animals have Do plants and animals have rights?rights?

Bill of RightsBill of Rights–– Life, liberty and Life, liberty and

pursuit of pursuit of h ih ihappinesshappiness

Natural Selection and EvolutionNatural Selection and EvolutionExtinction Extinction -- elimination of all individuals of elimination of all individuals of a particular species (local and global)a particular species (local and global)Natural phenomenon Natural phenomenon -- estimated that only estimated that only b 1b 1 2% f ll i h h i d2% f ll i h h i dabout 1about 1--2% of all species that have existed 2% of all species that have existed

are still around today.are still around today.Speciation Speciation -- appearance of a new speciesappearance of a new species

Accelerated ExtinctionAccelerated Extinction

Humans are among the most successful Humans are among the most successful species currently on earthspecies currently on earth–– AdaptableAdaptable–– intelligentintelligent–– high reproductive activityhigh reproductive activity–– few enemiesfew enemies

Human ImpactsHuman Impacts

Humans isolate ourselves from natureHumans isolate ourselves from natureHerman Daly”s perspective Herman Daly”s perspective –– We treat the We treat the Earth as if it were a corporation in Earth as if it were a corporation in li id tili id tiliquidationliquidationHuman Induced Extinction: Eroding the Human Induced Extinction: Eroding the Earth’s BiodiversityEarth’s Biodiversity

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Characteristics making a species Characteristics making a species vulnerable to extinctionvulnerable to extinction

Since things change, a species must adapt or Since things change, a species must adapt or become extinctbecome extinctExtinction happens more often whenExtinction happens more often when–– Species has a small populationSpecies has a small populationp p pp p p–– Low biotic potentialLow biotic potential–– Dispersed individualsDispersed individuals–– Occur in small, restricted areasOccur in small, restricted areas–– Species is very specializedSpecies is very specialized–– Non adaptive behaviorNon adaptive behavior

As Human Population GrowsAs Human Population Growsother species displaced (habitat alteration)other species displaced (habitat alteration)Species utilized as foodSpecies utilized as foodUsed as ornamentsUsed as ornamentsUsed for medicineUsed for medicineEliminated as pestsEliminated as pestsAll accelerate extinctionAll accelerate extinction

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Methods of Preventing Methods of Preventing ExtinctionExtinction

ZooZoo--botanical garden approachbotanical garden approachSpecies ApproachSpecies ApproachThe Ecosystem ApproachThe Ecosystem Approach

H bit t t tiH bit t t ti–– Habitat protectionHabitat protection–– Addressing habitat fragmentationAddressing habitat fragmentation–– Habitat Restoration Habitat Restoration –– SERSER

»»Green Belt Corridor ProjectGreen Belt Corridor ProjectImprove Wildlife ManagementImprove Wildlife ManagementScaling back human impactsScaling back human impacts

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What about tropical forest? Is What about tropical forest? Is there a solution?there a solution?

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ActionsActionsProtection of threatened and endangered Protection of threatened and endangered speciesspeciesCurrently, more action in developed Currently, more action in developed nations than in less developed nationsnations than in less developed nationsnations than in less developed nationsnations than in less developed nationsBias in protecting certain speciesBias in protecting certain species–– birdsbirds–– mammalsmammals–– butterfliesbutterflies–– a few mollusks, fish, and plantsa few mollusks, fish, and plants

ExtinctionsExtinctions

US Endangered Species Act (1973)US Endangered Species Act (1973)–– Attempts to protect threatened and Attempts to protect threatened and

endangered species from governmental endangered species from governmental actionsactionsactionsactions

–– Endangered Species Review CommitteeEndangered Species Review Committee»»7 member committee7 member committee»»Can grant exceptions to the Endangered Can grant exceptions to the Endangered

Species ActSpecies Act»»Does economics outweigh ecological Does economics outweigh ecological

effectseffects??

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ExtinctionsExtinctions

International Union for the International Union for the Conservation of Nature and Natural Conservation of Nature and Natural ResourcesResources–– Work without much power but much Work without much power but much

prestige around the world, prestige around the world, particularly in less developed nationsparticularly in less developed nations

Points to PonderPoints to Ponder

Paul Ehrlich says that human population has Paul Ehrlich says that human population has reached its present size by exploiting, degrading reached its present size by exploiting, degrading and depleting the Earth’s fossil fuels, minerals, and depleting the Earth’s fossil fuels, minerals, soils, water and biological diversitysoils, water and biological diversityE O Wil t d th t th fE O Wil t d th t th fE.O. Wilson contends that the consequences of E.O. Wilson contends that the consequences of widespread loss of species are far more widespread loss of species are far more devastating than fossil fuel depletion, economic devastating than fossil fuel depletion, economic collapse and limited nuclear war! He contends that collapse and limited nuclear war! He contends that it is the folly for which our descendants are least it is the folly for which our descendants are least likely to forgive us.likely to forgive us.What do you think ???????????What do you think ???????????