4.7+Extinct+Species+pd3

 

THREATENED, ENDANGERED AND EXTINCT SPECIES  (Discovery)  In the United States Alone... 150 Species Threatened, 540 Endangered, Countless

GONE FOREVER

**R** media type="file" key="Endangered_Species3.mov" width="386" height="362" (United Streaming Videos) = = = = = = = = = = = = = = =__What is a threatened species? __= A threatened species is any species that is vulnerable to extinction in the near future.

=__<span style="display: block; color: rgb(52, 243, 43); font-family: Verdana,Geneva,sans-serif; text-align: left">What is an endangered species? __= <span style="display: block; color: rgb(52, 243, 43); font-family: Verdana,Geneva,sans-serif; text-align: left">An endangered species is any species that is at risk of becoming extinct because it is losing its number of individuals or being threatened by a changing environment. =__<span style="display: block; color: rgb(52, 243, 43); font-family: Verdana,Geneva,sans-serif; text-align: left">What is an extinct species? __= <span style="display: block; color: rgb(52, 243, 43); font-family: Verdana,Geneva,sans-serif; text-align: left">An extinct species is a species that has become extinct, or no longer exists.

= = = = =General=

The most famous example of extinction is the mass extinction of the dinosaurs. This took place in the cretaceous period and is known as the Cretaceous-Tertiary extinction event. The most widely accepted theory of what caused this extinction is the event of multiple meteors colliding with the Earth. This would cause immediate deaths of many individuals, but the long term damage is more substantial. The meteors would kick up much debri and dust covering the Earth's atmosphere and preventing the majority of sunlight from ever reaching the ground. This would kill off many of the plant species that inhibited the world at the time. This would cause the upper ladder of the food chain to suffer immensely, and undergo extinction as well. These surviving organisms would also have to deal with climate changes. Although certain species can adapt to these changes, many cannot and will die off. Other scientists believe that this mass extinction took a more gradual outlook and died off due to changing sea-level and/or climate change.

(discovery)

(discovery)

A certain number of species survived by adapting and usually downsizing. Here the tyrannosaurus rex downgraded and adapted into some of the species we are know very familiar with such as the chicken or ostrich.

(discovery)

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<span style="color: rgb(255, 0, 31)"> =<span style="color: rgb(255, 0, 31)"><span style="font-family: Verdana,Geneva,sans-serif">__IUCN Red List__ = <span style="font-family: Verdana,Geneva,sans-serif"><span style="color: rgb(255, 0, 0)">"The IUCN Red List is the world's most comprehensive inventory of the global conservation status of plant and animal species. It uses a set of criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity" (IUCN, 2007). <span style="color: rgb(15, 16, 235)">* <span style="color: rgb(15, 16, 235)"><span style="font-family: Verdana,Geneva,sans-serif">  <span style="font-family: Verdana,Geneva,sans-serif"><span style="color: rgb(15, 16, 235)">In the 2008 issue, it was estimated that 1,226 species of birds are considered threatened with extinction. Out of the total 9,856 bird species, that means that a total of 12.4% of the known species are in danger of becoming extinct. <span style="color: rgb(47, 5, 250)"><span style="font-family: Verdana,Geneva,sans-serif">* On May 14, 2008, it was announced that the polar bear has become a threatened species. This topic had been being disputed for the past three years but was resolved due to the loss of Arctic Sea ice. =<span style="color: rgb(255, 0, 31)"> =

= = = = =<span style="font-size: 140%; color: rgb(54, 165, 29)">STANDARDS = **4.7.10.A./4.7.12.A.** Explain the significance of diversity in ecosystems./Analyze biological diversity as it relates to the stability of an ecosystem. **4.7.10.B.** Explain how structure, function and behavior of plants and animals affect their ability to survive. **4.7.12.B****.** Examine the effects of extinction, both natural and human caused, on the environment. **4.7.10.C.** Identify and explain why adaptations can lead to specialization. **4.7.12.C.** Analyze the effects of threatened, endangered or extinct species on human and natural systems.