| The Earth's species are
dying out at an alarming rate, up to 1000 times faster than their natural rate of
extinction. By carefully examining fossil records and ecosystem destruction, some
scientists estimate that as many as 137 species disappear from the Earth each day, which
adds up to an astounding 50,000 species disappearing every year.
Tropical rainforests contain at least half of the Earth's species. In Panama, scientists discovered fully 80% of the world's currently known beetle species on only 19 trees. The incredible diversity of the rainforests means that most species have evolved to inhabit very specialized niches in their environment; when humans disrupt that environment, many species cannot survive. Because species depend on each other in a complicated web of relationships, changing just one part of that web harms the entire ecosytem: as people destroy or significantly change the rainforests, certain species die out, and as they go extinct, other species die out, which in turn leads to further breakdown of the ecosystem. This breakdown of rainforest ecosystems will likely lead to the disappearance of up to 10% of the world's species within the next 25 years unless we act to stop it.
Species extinction is a natural part of evolution; why, then, should accelerated extinction rates concern us?
Many indigenous people survive directly off of the resources found in the rainforests.
They eat wild game, use the plants for food and medicine, and may identify certain species
as a sacred and essential part of their heritage. When these resources are destroyed, the
people lose their homes, their food, and their very culture. And they may be forced to
look to protected, endangered areas of forest for shelter and food, leading to further
destruction and extinction.
|Causes of Extinction
Why are species vanishing at such an alarming rate? Habitat destruction ranks as the leading cause - especially logging, mining, clearing trees for cattle grazing and building dams and highways where rainforests once existed. As the ecosystem shrinks, more and more species lose the resources that they need to survive.
Over-consumption and international trade further endanger certain species. In Africa, commercial hunting is responsible for putting 1/3 of the currently threatened primary forest at risk. Species populations can also shrink when local people are forced by habitat destruction to rely on a smaller area for their food needs, or when a certain species becomes popular on the international market. People trap or kill animals and ship them to other countries, where they are taken as pets or used to make other products. Once a species becomes rare or protected, the profit in smuggling can increase.
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