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Local extinction: a species is no longer found in a portion of
its range
Ecological extinction: so few members of a popula...
• Endangered: a species in danger of becoming
extinct over all or most of its natural range
• Threatened: a species in dan...
Population genetics and demographic phenomena affect the evolution,
and therefore the risk of extinction, of species. Limi...
Genetic pollution is undesirable and uncontrolled gene flow into
wild populations.
Genetic pollution, genetic contaminatio...
Habitat degradation is currently the main anthropogenic cause
of species extinctions.
The main cause of habitat degradat...
Introduction of new competitor species are also a factor in
extinction and often accompany habitat degradation, as
well.
S...
Coextinction refers to the
loss of a species due to the
extinction of another; for
example, the extinction
of parasitic i...
Our climate is changing, both naturally and due to human exploitation. There is
already undeniable evidence that animals, ...
• Probably 500 million species have existed over time
• “Background” rate of extinction: Amount of species that went
extin...
• Extinctions will lead to ecological disaster is
an exaggeration.
e.g.: Fossil evidence shows that mass
extinctions have ...
• Economic or Medical uses
• Scientific and Ecological reasons
• Aesthetics and Recreation
• Ethical reasons
• Extinction ...
• The future of our natural environment is becoming
uncertain as wildlife and wildlife habitats
disappear.
• Every species...
• Federal Endangered Species Act
• California Endangered Species Act
• California Environmental Quality Act
• California D...
Extinction
Extinction
Extinction
Extinction
Extinction
Extinction
Extinction
Extinction
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Extinction

a presentation on endangered and extinct animals

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Extinction

  1. 1. Local extinction: a species is no longer found in a portion of its range Ecological extinction: so few members of a population are left that it can no longer serve its purpose in the ecosystem Biological extinction: a species is no longer found anywhere on earth
  2. 2. • Endangered: a species in danger of becoming extinct over all or most of its natural range • Threatened: a species in danger of becoming endangered in the near future • Rare: species that are limited in their distribution
  3. 3. Population genetics and demographic phenomena affect the evolution, and therefore the risk of extinction, of species. Limited geographic range is the most important determinant of genus extinction at background rates but becomes increasingly irrelevant as mass extinction arises. Effects that cause or reward a loss in genetic diversity can increase the chances of extinction of a species.
  4. 4. Genetic pollution is undesirable and uncontrolled gene flow into wild populations. Genetic pollution, genetic contamination or genetic swamping happens when original set of naturally evolved (wild) region specific genes /gene pool of wild animals and plants become hybridized with domesticated and feral varieties or with the genes of other nonnative wild species or subspecies from neighboring or far away regions.
  5. 5. Habitat degradation is currently the main anthropogenic cause of species extinctions. The main cause of habitat degradation worldwide is agriculture, with urban sprawl, logging, mining and some fishing practices close behind. The degradation of a species' habitat may alter the fitness landscape to such an extent that the species is no longer able to survive and becomes extinct.
  6. 6. Introduction of new competitor species are also a factor in extinction and often accompany habitat degradation, as well. Sometimes these new competitors are predators and directly affect prey species, while at other times they may merely out-compete vulnerable species for limited resources.
  7. 7. Coextinction refers to the loss of a species due to the extinction of another; for example, the extinction of parasitic insects following
  8. 8. Our climate is changing, both naturally and due to human exploitation. There is already undeniable evidence that animals, birds and plants are being affected by climate change and global warming in both their distribution and behavior. Unless greenhouse gas emissions are severely reduced, climate change could cause a quarter of land animals, birdlife and plants to become extinct.
  9. 9. • Probably 500 million species have existed over time • “Background” rate of extinction: Amount of species that went extinct before humans became the dominant species on earth • With the advent of agriculture species extinctions have increased dramatically – 8000 b.c. to a.d. 1600, one species went extinct every thousand years – In 1985 1000 species went extinct every year – In 2000, between 20,000 and 50,000 species are considered doomed to extinction every year
  10. 10. • Extinctions will lead to ecological disaster is an exaggeration. e.g.: Fossil evidence shows that mass extinctions have occurred many times throughout the history of life. • By the principle of “survival of the fittest”. Life forms that cannot keep up with the rapid changing world will always risk extinction, unless they adapt to the new challenges.
  11. 11. • Economic or Medical uses • Scientific and Ecological reasons • Aesthetics and Recreation • Ethical reasons • Extinction is forever
  12. 12. • The future of our natural environment is becoming uncertain as wildlife and wildlife habitats disappear. • Every species in our world plays a unique role in earth's intricate ecosystems. • Plants, animals and humans live together on the same land and water, and they are interdependent on each other for survival in the way that we do not fully understand.
  13. 13. • Federal Endangered Species Act • California Endangered Species Act • California Environmental Quality Act • California Department of Fish and Game Code

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