G9 Science Q1- Week 5- Extinction.ppt quarter 1

Science 9

1. Extinction
PREPARED BY: TYPE YOUR NAME HERE

2. What is Extinction?
Extinction occurs when the last existing
member of a given species dies
In other words…there aren’t any more left!
It is a scientific certainty when there are not
any surviving individuals left to reproduce
Functional Extinction
Only a handful of individuals are left
Odds of reproduction are slim

3. Causes of Extinction
Genetics and Demographics
Small populations = increased risk
Mutations
Causes a flux in natural selection
Beneficial genetic traits are overruled
Loss of Genetic Diversity
Shallow gene pools promote massive
inbreeding

4. Causes Con’t.
Habitat Degradation
One of the most influential
Has many causes
Some due to humans
Some due to other factors

5. Habitat Degradation
Toxicity
Kills off species directly through
food/water
Indirectly via sterilization
Can occur in short spans (a single
generation)
Can occur over several generations
Increasing toxicity
Increasing competition for habitat
resources

6. Habitat Degradation
Destruction of Habitat
“Save the Rainforests!”
Elimination of living space
Change in habitat
Rainforest to pasture lands
Leads to diminishing resources
Increases competition
Can be caused by natural processes
Volcanoes, floods, drought, etc…

7. Causes Con’t.
Predation
Competition
Disease
Coextinction
Mass Extinction
Planned Extinction

8. Predation
Introduction of predators
Invasive alien species
Transported by humans
Cattle, rats, zebra muscles, etc…
Sometimes on purpose, sometimes not
Can eat other species
Eat food sources
Introduce diseases

9. Coextinction
The loss of one species leads to the loss of
another
Chain of extinction
Can be caused by small impacts in the
beginning
A predator looses its food source
Affected by interconnectedness in nature

10. Mass Extinction
Aka: an extinction event
A sharp decrease in the number of species
on Earth in a short period of time
Coincides with a sharp drop in speciation
The process by which new biological species
arise
There have been at least 5
Last one was 65M years ago

11. Mass Extinction Diagram

12. Mass Extinction
Nearly 2/3rds (or more) of all animal
species that ever existed on the planet are
now gone.
With contemporary extinction being attributed to
HUMAN activity.
Numerous factors go into the extinction of
a specific species.
Though all point the finger to climate change.

13. Mass Extinction
Began about three-million years ago
(Continental Glaciations).
Hypotheses for initial extinction:
Sea level depletion vs. Temperature decrease
Though these hypotheses aren’t mutually
exclusive, they may have conspired together.

14. Mass Extinctions
1.Cretaceous-Tertiary Extinction (65).
2.End Triassic Extinction (200).
3.Permian Triassic Extinction (250).
4.Late Devonian Extinction (364).
5.Ordovician-Silurian Extinction (440).
(#= millions of years ago)

15. Planned Extinction
Human controlled
Thought of to help humans
Deadly viruses
Smallpox
Extinct in the wild
Polio
Near extinct (only in small parts of the world)

16. Natural
Causes of
Extinction

17. Climatic Heating and
Cooling

18. Changes in Sea Level or
Currents
www.johnstonsarchive.net/spaceart/cylmaps.html

19. Asteroids
Causes complete devastation
Flattening and crater at
or around impact site-hundreds of miles
wide
Reverberations felt around the world

20. Cosmic Radiation
www.iit.edu/~ipro313s/home.html

21. Acid Rain
Kills acid intolerant
species

22. Disease/Epidemics
Can wipe out entire
species
Frog with fungus
disease
Killing frogs and
other amphibians

23. Spread of Invasive Species

24. 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

25. Human Causes of
Extinction

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

27. Extinctions caused by humans are generally
considered to be a recent phenomena.
HOWEVER:
•In Australia—earliest humans: 64,000 years ago
extinction—30,000-
60,000 years ago
•In the Americas—80% of large animals
became extinct around the same time as first human
presence there

29. Based on these, and other
studies done by The
international Union for
Conservation of Nature
and Natural Resources
(IUCN), human induced
extinctions are not
necessarily a new
phenomena. However,
extinction by humans
today is becoming much
more rapid.

30. The rapid loss of species today is estimated by some
experts to be between 100 and 1,000 times higher
than the natural extinction rate, while others
estimate rates as high as 1,000-11,000 times higher.

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

32. Climate change/Global Warming
John W. Williams from UW-Madison suggests that
changes in regions such as the Peruvian Andes,
portions of the Himalayas and southern Australia
could have a profound impact on indigenous plants
and animals
Williams and his research partners used computer
models to estimate how various parts of the world
would be affected by regional changes consistent
with the IPCC's climate models.
Their findings indicated that “By the end of the 21
st

century, large portions of the Earth’s surface may
experience climates not found at present and some
2th century climates may disappear.”

33. Their studies also suggest isolated climates such as the
Peruvian Andes could change drastically enough to
lead to species extinctions.
The climate change might also create new climates,
providing new opportunities for other species to thrive,
Williams said.
Regions where
novel climates are
expected to form
in tropical and
subtropical regions
include the
western Sahara,
southeastern U.S.
and eastern India.

34. Extinction Hotspots

35. Where and what are
hotspots?
“The concept of biodiversity hotspots
was penned by British ecologist
Norman Myers in 1988 as a means to
address the dilemma of identifying the
areas most important for preserving
species.” (national geographic)
Hotspots are included in 6 continents
excluding Antarctica.
Hotspots are heavily distributed along
shore lines and near the equator.

36. Hotspots are effected by many factors including
Logging
Agriculture
Hunting
Climate change
Government
Hotspots can be added and removed from the classification
of “hotspot” by what recovery or lack of prevention is taking
place in each area.

37. What is required to be
considered a hotspot
“The region must support at least 1,500 plant
species found nowhere else in the world, and it
must have lost at least 70 percent of its original
habitat.”

38. Interactive maps
http://www.biodiversityhotspots.org/xp/Hotspots/
home/interactive_map.xml
http://www.zeroextinction.org/pointmapper/azefi
les/index.html

39. What is Biodiversity?
Biodiversity is the variation of taxonomic life
forms for a given biome or ecosystem
Boosts Ecosystem productivity
Measure of the health of a biological system

40. Benefits of Biodiversity
Food and drink
Medicines
Industrial materials
Ecological services
Leisurely, cultural, and
aesthetic values

41. Causes of Biodiversity Loss
Pollution
Loss of tropical forest
Spread of urban areas
Warfare
Large dam
construction
Road building
Tourism
Loss of traditional
lifestyles

42. Consequences of Biodiversity
Loss
Loss of food
Decrease in biomass
Collapse of food web
Loss of keystone species
Reduction of ecosystem
efficiency and
community productivity
Loss of medicinal
supplies
Increased vulnerability
of species to disease
and predation

43. Crops
MONOCULTURE OF CROPS LETS THE YIELD BECOME
SUSCEPTIBLE TO PESTS OR VIRUSES
75% OF CROP VARIETIES ARE EXTINCT
DUE TO THE SPREAD OF MODERN AGRICULTURE

44. Tropical Forest Cutting
Cover 13% of Earth
Home to 50% of all known plant and
animal species
FAO reports 15.4 million hectares are
destroyed annually

45. The Convention on
Biological Diversity
Mission Statement
“The objectives of this convention are
the conservation of biological
diversity, sustainable use of its
components and the fair and
equitable sharing of the benefits
arising out of the utilization of genetic
resources.”
Since it was adopted at the Earth Summit in Rio de
Janeiro in 1992, 189 countries have signed and
implemented it. The United States signed it in 1993
but has yet to put it into action still today

46. The Convention on
Biological Diversity
2010 Biodiversity Target
Members adopted a plan to significantly
reduce the present rate of biodiversity
loss at the global, regional and national
level by the year 2010.

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