The document discusses extinction and biodiversity loss. It defines extinction as occurring when the last member of a species dies. The passenger pigeon is provided as an example, with the last one dying alone in a zoo in 1914 after the species was already functionally extinct in the wild. Major causes of extinction discussed include habitat degradation and destruction from human activities like pollution, climate change, and overpopulation. Statistics are given on current extinction rates from human impacts being 1500 times the natural rate, with many species projected to be lost in the coming centuries if trends continue. The major impacts of biodiversity loss on human concerns like medicine, agriculture, ecosystem services, and moral obligations are also briefly touched on.

1. Extinctions: The EndExtinctions: The End
of Biodiversityof Biodiversity

2. What is Extinction?What is Extinction?
 Extinction occurs when the last existingExtinction occurs when the last existing
member of a given species diesmember of a given species dies

In other words…there aren’t any more left!In other words…there aren’t any more left!
 It is a scientific certainty when there areIt is a scientific certainty when there are
not any surviving individuals left tonot any surviving individuals left to
reproducereproduce
 Functional ExtinctionFunctional Extinction

Only a handful of individuals are leftOnly a handful of individuals are left

Odds of reproduction are slimOdds of reproduction are slim

3. The passenger pigeonThe passenger pigeon
 The last passenger pigeon inThe last passenger pigeon in
Wisconsin was shot in 1899.Wisconsin was shot in 1899.
 This was reportedly the last passengerThis was reportedly the last passenger
pigeon shot in the wild.pigeon shot in the wild.
 The last Passenger Pigeon, named Martha,The last Passenger Pigeon, named Martha,
died alone at Zoo in 1914.died alone at Zoo in 1914.
 Even when Martha was still alive, the speciesEven when Martha was still alive, the species
was already functionally extinct – it wouldwas already functionally extinct – it would
never return to a sustainable population.never return to a sustainable population.

4. Causes of ExtinctionCauses of Extinction
 GeneticsGenetics

Small populations = increased riskSmall populations = increased risk

MutationsMutations
• Causes a flux in natural selectionCauses a flux in natural selection
• Beneficial genetic traits are overruledBeneficial genetic traits are overruled

Loss of Genetic DiversityLoss of Genetic Diversity
• Shallow gene pools promote massive inbreedingShallow gene pools promote massive inbreeding

5.  Extinctions occur when the environment ofExtinctions occur when the environment of
a species changes faster than the speciesa species changes faster than the species
can adapt.can adapt.
 Extinctions can be local, widespread, orExtinctions can be local, widespread, or
global.global.

For example, the timber wolf was until recentlyFor example, the timber wolf was until recently
extinct in Wisconsin but not in Minnesotaextinct in Wisconsin but not in Minnesota

Wild elk and woodland caribou are now extinctWild elk and woodland caribou are now extinct
in Wisconsin but may be found on gamein Wisconsin but may be found on game
farms.farms.

6. Habitat DegradationHabitat Degradation
 ToxicityToxicity

Kills off species directly through food/waterKills off species directly through food/water

Indirectly via sterilizationIndirectly via sterilization

Can occur in short spans (a single generation)Can occur in short spans (a single generation)

Can occur over several generationsCan occur over several generations
• Increasing toxicityIncreasing toxicity
• Increasing competition for habitat resourcesIncreasing competition for habitat resources

7. Habitat DegradationHabitat Degradation
 Destruction of HabitatDestruction of Habitat

““Save the Rainforests!”Save the Rainforests!”

Elimination of living spaceElimination of living space

Change in habitatChange in habitat
• Rainforest to pasture landsRainforest to pasture lands

Leads to diminishing resourcesLeads to diminishing resources
• Increases competitionIncreases competition

Can be caused by natural processesCan be caused by natural processes
• Volcanoes, floods, drought, etc…Volcanoes, floods, drought, etc…

8. CoextinctionCoextinction
 The loss of one species leads to the lossThe loss of one species leads to the loss
of anotherof another
 Chain of extinctionChain of extinction
 Can be caused by small impacts in theCan be caused by small impacts in the
beginningbeginning
 A predator looses its food sourceA predator looses its food source
 Affected by interconnectedness in natureAffected by interconnectedness in nature

9. Planned ExtinctionPlanned Extinction
 Human controlledHuman controlled
 Thought of to help humansThought of to help humans
 Deadly virusesDeadly viruses

SmallpoxSmallpox
• Extinct in the wildExtinct in the wild

PolioPolio
• Near extinct (only in small parts of the world)Near extinct (only in small parts of the world)

10. Natural Causes ofNatural Causes of
ExtinctionExtinction

11. Climatic Heating and CoolingClimatic Heating and Cooling

12. Changes in Sea Level or CurrentsChanges in Sea Level or Currents
 www.johnstonsarchive.net/spaceart/cylmaps.htmlwww.johnstonsarchive.net/spaceart/cylmaps.html

13. Cosmic RadiationCosmic Radiation
 www.iit.edu/~ipro313s/home.htmlwww.iit.edu/~ipro313s/home.html

14. Acid RainAcid Rain
 Kills acid intolerantKills acid intolerant
speciesspecies

15. Disease/EpidemicsDisease/Epidemics
 Can wipe out entireCan wipe out entire
speciesspecies
 Frog with fungusFrog with fungus
diseasedisease
 Killing frogs and otherKilling frogs and other
amphibiansamphibians

16. Natural factors usually occur at a slower
rate and therefore cause a low extinction
rate.
Human activities occur at a faster rate
and cause higher extinction rates.
Human activities are mostly responsible
for the present extinction rates.
http://www.gov.mb.ca/conservation/sustain/extinct.pdf

17. Human Causes of
Extinction

18. Top Human Causes of
Extinction:
Increased human population
Destruction/Fragmentation of
habitat
Pollution
Climate change/Global warming

19. Habitat Degradation
Habitat loss and degradation affect 86%
of all threatened birds, 86% of mammals and
88% of threatened amphibians

20. Current StatsCurrent Stats
 9090% of all large fish have disappeared in the last 50 years due to% of all large fish have disappeared in the last 50 years due to
over-fishing.over-fishing.

Myers, Ransom. Worm, Boris. Biology Department, Dalhousie University, Halifax, Nova Scotia, Canada, RapidMyers, Ransom. Worm, Boris. Biology Department, Dalhousie University, Halifax, Nova Scotia, Canada, Rapid
Worldwide Depletion of Predatory Fish Communities. Nature. Volume 423. P. 280. May 2003Worldwide Depletion of Predatory Fish Communities. Nature. Volume 423. P. 280. May 2003
 3030% of North American songbird species are in significant decline.% of North American songbird species are in significant decline.
 One in eightOne in eight plant species are in danger of extinction within the nextplant species are in danger of extinction within the next
30 years (ICUN Red List)30 years (ICUN Red List)
 The current rate of extinction isThe current rate of extinction is 15001500 times greater than the normal,times greater than the normal,
sustainable extinction rate.sustainable extinction rate.

Bjørn Lomborg, The Skeptical Environmentalist: Measuring the Real State of the World, Cambridge U. Press,Bjørn Lomborg, The Skeptical Environmentalist: Measuring the Real State of the World, Cambridge U. Press,
Cambridge, 2001.Cambridge, 2001.
 ““HalfHalf of bird and mammal species will be gone in 200 to 300 years”of bird and mammal species will be gone in 200 to 300 years”

Levin, Phillip and Levin, Donald. The Real Biodiversity Crisis. January, 2002.Levin, Phillip and Levin, Donald. The Real Biodiversity Crisis. January, 2002. American ScientistAmerican Scientist,, VolumeVolume
90, Number 1, Page 690, Number 1, Page 6
 One species is going extinct every 20 minutes.One species is going extinct every 20 minutes.

Levin, Phillip and Levin, Donald. The Real Biodiversity Crisis. January, 2002. American Scientist, VolumeLevin, Phillip and Levin, Donald. The Real Biodiversity Crisis. January, 2002. American Scientist, Volume
90, Number 1, Page 690, Number 1, Page 6

21. Modern Causes of ExtinctionsModern Causes of Extinctions
 Major current causes of extinctions include:Major current causes of extinctions include:

Habitat LossHabitat Loss: fragmentation, degradation, and: fragmentation, degradation, and
outright destruction of ecosystems that supportoutright destruction of ecosystems that support
native ecosystems (leading cause).native ecosystems (leading cause).

Invasive SpeciesInvasive Species: the introduction or: the introduction or
overpopulation of species that over-consumeoverpopulation of species that over-consume
natural resources and are uncontrolled bynatural resources and are uncontrolled by
predators (second leading cause).predators (second leading cause).

Over-harvestingOver-harvesting: the removal of species at rates: the removal of species at rates
that exceed reproductionthat exceed reproduction

PollutionPollution: introduction of harmful agents that: introduction of harmful agents that
reduce the effectiveness of a species’reduce the effectiveness of a species’
adaptationsadaptations

22.  Major Human concernsMajor Human concerns

23. Biodiversity & MedicineBiodiversity & Medicine

24. Biodiversity & AgricultureBiodiversity & Agriculture

25. Biodiversity & CropsBiodiversity & Crops

26. Biodiversity & Ecosystem ServicesBiodiversity & Ecosystem Services
 Ecosystem services include air and waterEcosystem services include air and water
purification, detoxification and decomposition ofpurification, detoxification and decomposition of
wastes, climate regulation, regeneration of soilwastes, climate regulation, regeneration of soil
fertility, and the production and maintenance offertility, and the production and maintenance of
biological diversity.biological diversity.
 These are the key ingredients of our agricultural,These are the key ingredients of our agricultural,
pharmaceutical, and industrial enterprises.pharmaceutical, and industrial enterprises.
 Such services are estimated to be worth trillions ofSuch services are estimated to be worth trillions of
dollars annually.dollars annually.

We get these services for free…for now.We get these services for free…for now.

http://www.fws.gov/endangered/esa-http://www.fws.gov/endangered/esa-
library/pdf/Why_Save_Endangered_Species_Brochure.pdflibrary/pdf/Why_Save_Endangered_Species_Brochure.pdf

27. Biodiversity & Moral ObligationsBiodiversity & Moral Obligations