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Chapter 10 Biodiversity. 10.1 Biodiversity at Risk. … In wilderness is the Preservation of the world. A mass extinction is the Extinction of many species during A relatively short period of time. The earth has experienced 5 mass extinctions, each Probably caused by some change
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Chapter 10 Biodiversity
10.1 Biodiversity at Risk … In wilderness is the Preservation of the world.
A mass extinction is the Extinction of many species during A relatively short period of time. The earth has experienced 5 mass extinctions, each Probably caused by some change In climate.
Many scientists believe that we Are living in another mass Extinction that would leave 25% of all species extinct By the year 2100. If this is true, it will be the First caused by an organism… Humans!
The term biodiversity refers To the number of variety Of species on Earth. Of the approximately 1.6 million Species on earth, most Are insects.
The human population is Increasing by about 220 000 People each day!! Because the human population Is growing so rapidly, we are Causing other species to Become extinct at an Accelerated rate.
As human populations grow, we Use more land to build homes And harvest resources. It is estimated that habitat loss Causes almost 75% of the Extinctions now occurring.
Most extinctions are Occurring in tropical rain forests When land is cleared for Farming or cattle grazing. Unregulated hunting can also Lead to species extinction.
In the early 1900’s the American Passenger pigeon was Legally hunted to extinction. Similarly, the American buffalo Was nearly hunted to extinction In the 1800’s.
In many countries, Poaching (illegal hunting), can threaten Animals with extinction. This happened to elephants In 1979 when poachers were Hunting the beasts to meet the demand for ivory tusks.
An exotic species is a species that Is not native to a particular Region. Even such familiar organisms Such as cats and rats, are Considered to be exotic when They are brought to regions Where they have never Lived before.
Species, along with abiotic Factors, are what make Up ecosystems. Each species plays a role In its ecosystem. Some species are so important To the functioning of an Ecosystem that they are Called keystone species.
When sea otters were hunted To near extinction on the Pacific coast, their entire Ecosystem was disrupted.
There are also practical uses For certain species. About 40% of all prescription Drugs were derived from Living things.
So scientists are concerned That the loss of biodiversity, Especially in the Rain forests, Will limit the development Of future medicines.
10.2 Public Policy The united states congress Passed the Endangered Species Act in 1973 and has amended It several times.
This law is designed to Protect plant and animal Species in danger of extinction. There are 4 main provisions… Under the 1st main provision, The US Fish and Wildlife Service must compile a list of All endangered and threatened Species.
To be considered endangered, A species numbers must have Fallen so low that it is likely To become extinct in the Near future. Threatened species are species That are likely to become Endangered if they are Not protected.
The second main provision states That endangered or threatened Animals may not be caught. None of the species, nor any Of their parts, can be sold Or traded.
According to the 3rd provision, The federal government May not carry out any project That jeopardizes an Endangered species. And the 4th provision says that A recovery plan for each Endangered or threatened Species.
There are also international Organizations to help species. The world wildlife fund works To protect biodiversity, Especially in rain forests. The Nature Conservancy Currently manages over 1500 nature sanctuaries.
Greenpeace International Stages dramatic protest to stop The killing of animals. The international union for the Conservation of nature and Natural resources is in the Forefront of efforts to protect Species and habitats.
10.3 The Future of Biodiversity It is possible to slow the loss of Species, but to do so we must Develop new approaches to Conservation and a sensitivity To human needs around the globe.
Additional ways to preserve Individual species include Captive-breeding programs, Botanical gardens, and Germ-plasm banks.
Germ-plasm banks store germ Plasm for future use in case Species become critically Endangered. Germ-plasm is the genetic material Contained within the reproductive Cells of organisms.
Zoos and wild-animal parks Can increase the population Of an endangered or Threatened species by Establishing captive-breeding Programs. Such programs involve breeding Animals under carefully Managed circumstances.
Botanical gardens worldwide House 90 000 species of plants. Even so, the gardens don’t have The space of the funds to Preserve most of the worlds Rare and threatened plants.
Recently, many Conservationists have begun To concentrate on protecting Entire ecosystems. This helps to save many organisms That can’t be placed on lists And these ecosystems can Help save the entire planet.
