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By: Mary A. Rodrigues The Accelerating Loss of Species: The Sixth Extinction
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Mass Extinctions A Mass Extinction is: When at least half of all species (including animals and plants) die within a relatively short time. We know these extinctions occurred Through the fossil record Fossils of plants and animals in early layers are suddenly not present in later rock layers Scientists believe that 99% of all plant and animal species that have ever lived are now extinct
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The First Five Extinctions 1 st (Ordivician-Silurian) Extinction: 440 mya Caused by: sudden global cooliing Extinction of marine organisms 2 nd (Denovian) Extinction: 370 mya Caused by: possible climate change Extinction of tropical marine species 3 rd (Permian-Triassic) Extinction: 245 mya Caused by: climate change, plate tectonic movements, possible comet or meteor impact. largest mass extinction (so far) Killed a range of species, including vertebrates Only 10% of species survived
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4 th (Triassic-Jurrasic) Extinction: 210 mya Unknown cause Extinction of land vertebrates 5 th (Cretaceous-Tertiary) Extinction: 65 mya Caused by: collision of comet or meteor and/or volcanic eruption Extinction of dinosaurs, marine life, and many other plant and animal species 50-75% of animals extinct Global temperature decreased Rise of the primates
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How is the Sixth Extinction Different? The sixth extinction is happening today All other mass extinctions were caused by natural disasters, the sixth extinction is being caused by modern humans
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When did the Sixth Extinction begin? When modern homo sapiens began to radiate to different parts of the world. Only in places where early hominids lived, (Africa, Europe and Asia) did native plant and animal species survive in the beginning. Some paleoanthropologists believe that the Neanderthals became extinct due to warfare or competition from modern humans.
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Quickly after the arrival of modern humans, native species began to disappear. North America – 12,500 years ago Butchering killed off mammoths, mastodons, ancient buffalos Caribbean – 8,000 years ago Lost all larger native species Madagascar – 2,000 years ago Lost larger lemurs, elephant birds, a species of hippo, etc.
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How are modern humans causing the Sixth Extinction? 1. Pollution 2. Warfare 3. Exploitation of Species 4. Overpopulation 5. Unnatural Rates of Consumption
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6-Agriculture “ Single most profound ecological change in the entire 3.5 billion history of life”(Eldredge,N.) - Pre-agricultural humans lived in niches in ecosystem and worked with nature. - Agriculture was invented 10,000-12,000 years ago in the Middle East - Agricultural humans live outside the natural ecosystem. -Accelerated rates of extinction Humans do not have to rely on other species for survival Humans do not have to rely on ecosystem’s carrying capacity (how many species a local habitat can sustain)
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Agriculture (continued) Results in: Modern Humans living outside the natural eco-system Treating native plants as weeds Treating native animals/insects as pests
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The Sixth Extinction: Specifics 30,000 species are lost annually (3 species an hour) Up to 1/5 of all living species could become extinct within 30 years Nearly all loss is due to human activity Mostly through the destruction of plant and animal habitats
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What can we do to help? -get informed -get involved http://www.well.com/~davidu/extinction.html http://en.wikipedia.org/wiki/Mass_extinction http://en.wikipedia.org/wiki/Sixth_extinction http://images.google.com http://www.amnh.org/exhibitions/dinosaurs/extinction/ mass.php http://www.amnh.org/exhibitions/dinosaurs/extinction/ mass.php Park, M. (2002). Biological anthropology. 3 rd edition. Boston:McGraw-Hill.
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The Great Apes: Their Battle Against Extinction By: Angela Rodrigues
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What is the Status of the Great Apes? Chimpanzees: 150, 000 Bonobos: 50,000-100,000 Gorillas: 130,000 (wild), 350 (captive) Orangutans:12,000-15,000 remaining in Borneo Chimps, Bonobos, and Gorilla Distribution: Africa Orangutan Distribution: Asia
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Chimpanzees/Bonobos: Status: Endangered 1. Habitat Loss: Human population increase; Africa has highest growth rate in world! 2. Biomedical Research: Used as “models” for human diseases; 99% similar DNA 3. Disease: HIV Ebola 4. Hunting: Bushmeat Trade Fact: The only true threat to Great Apes are humans
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Gorillas: Gorilla gorilla Status: Critically Endangered 1. Habitat Loss: Deforestation-Competition for natural resources 2. Disease: Ebola 3. Poaching: Not for food Traps for other animals Threats:
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Orangutan: Pongo pygmaeus Status: Critically Endangered 1. Habitat Loss: Palm Oil Plantations: “Slash and Burn”-a process of clearing areas for agriculture by setting it on fire. Logging: 80% is done illegally 2. Pet Trade Infant’s mother killed to obtain baby. 4-5 orangutans die for every baby reaching the market 3. Poaching Bushmeat
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Bushmeat Trade: #1 Threat Over 1 million metric tons of bushmeat are distributed per year in Africa—not all are Great Apes, however. No longer is this done just by poor locals needing food/income; it is becoming a commercial business 40-60% of Africans rely on bushmeat for source of protein Not just a Great Ape problem; many endangered animals, such as leopards and elephants, are also killed yearly.
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What Does Their Future Hold? Some Statistics: For every 20,000 humans, there is one chimpanzee It is estimated that apes may become extinct within the next generation Some estimates even say that some species may be extinct as soon as 5-10 years! The bottom line: People need to be educated about the seriousness of the Great Ape Extinction We started this extinction: it is up to us to end it. If we don’t help, who will?
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References: 1. Great Apes in Peril (2001). BBC World News. Retrieved May 1, 2006, from http://news.bbc.co.uk/1/hi/sci/tech/1341609.stm 2. The BushMeat Trade (2005). Retrieved May 1, 2006, from http://www.rainforestlive.org.uk 3. Chimpanzee Conservation (2006). The Jane Goodall Institute. Retrieved April 27, 2006, from http://www.janegoodall.org/default.asp 4. Primate Info Net (2005). Retrieved April 26, 2006, from University of Wisconsin- Madison: http://pin.primate.wisc.edu/about.htmlhttp://pin.primate.wisc.edu/about.html 5. Orangutan Conservancy (2006). Retrieved April 26, 2006, from http://www.orangutan.com/orangutans_threats.html http://www.orangutan.com/orangutans_threats.html 6. Great Ape Project (2006). Retrieved May 1, 2006, from http://en.wikipedia.org from Wikipedia.http://en.wikipedia.org 7. Threats to Gorillas (n.d.). Retrieved May 26, 2006, from http://www.mountaingorillas.org/gorillas/gorillas_threats.htm http://www.mountaingorillas.org/gorillas/gorillas_threats.htm 8. Park, M. (2005). Biological Anthropology (4 th ed.). New York: McGraw-Hill Companies.
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