3.3 Biodiversity MMS, RAYEON, DANIEL, ALEX D, MIKU,GABRIEL

Key Concept: In what ways is biodiversity valuable?  Biodiversity is important to preserve, since wild organisms and ecosystems are a source of beauty and recreation.  Biodiversity: The number of different species in an area.  In addition biodiversity has both economic and ecological value within an ecosystem.

Economic Value  Ecosystem like rain forests, savannas, mountain ranges, provide companies locations for the wildlife tour. This also provides source of jobs and money for nations like Brazil, Costa Rica, and Kenya.

Ecological Value  Keystone Species: species that influences the survival of many other species in an ecosystem.  For example, the sea stars prey mostly on the mussels that live in tide pools.  Then when the researchers removed the sea stars from an area, the mussels began to outcompete many of the other species.

Key Concepts: What factors affect an area’s biodiversity?  Factors that affect biodiversity in an ecosystem include area, climate, and diversity of niches.

Area  Within an ecosystem, a large area can contain more types of species than the small areas.  For example, if you count the number of tree species, there would be way more types in the 100 square inches forest than the 10 square inches forest.

Climate  The number of species existing increases from the poles toward the equator.  For example, the tropical rain forests have no continuous changes in temperature, and large amounts of rainfall throughout the year.  And so, many plants grow in this area.

Niche Diversity What are Niche Diversity? Niche diversity refers to the evolutionary process in which species split in order to take advantage of open niches in their environment. This can be seen in areas where there are many very similar species that have brought down from a common ancestor.  Coral reefs are the second most diverse ecosystems in the world  Reefs are home to 20% of the world's saltwater species  A reef supports many different niches for organisms that live under, on, and among the coral.

Gene Pool Diversity  Genes are the structures in an organism's cells that carry its hereditary information.  Genes decide an organism's characteristics, from its size and appearance to its ability to fight disease.  In one species, they share a lot of genes, but they are all different from each other. And these differences make up the gene pool of that species

Extinction of species  Extinction is the disappearance of all members of a species from Earth.  Nowadays, more and more species are becoming extinct due to people's hunt.  Endangered Species: The species that are in danger of becoming extinct in the near future.  People hunted the birds, killing many hundreds of thousands.

Causes of Extinction  Human activities can also threaten biodiversity. These are some of the causes:  Habitat Destruction  Poaching  Pollution  Exotic Species

Habitat Destruction  The major cause of extinction is habitat destruction, the loss of a natural habitat.  Breaking larger habitats into smaller, isolated pieces, or fragments, is called habitat fragmentation.  Destructing where animals live, is the shortcut for killing all of them.

Poaching  The illegal killing or removal of wildlife from their habitats is called poaching.  A lot of animals are hunted by human, and they are hunted for a part of them. Then the hunters sell the animals they caught.  For example, Tropical fish, tortoises, and parrots are popular pets now, which makes them very valuable poachers.

Pollution  Some species are endangered because of pollution.  The pollutants reach animals through what they eat, breathe or in mud.  And the pollutant can kill organisms or cause birth effects.

Exotic Species  Introducing exotic species into a different ecosystem can cause a lot of problems.  For example, rats that were exposed into Hawaii, ate up eggs of the nene goose. People suggested bringing in rat-eating mongoose to Hawaii, and it ended up that mongoose prefer eating nene goose eggs than rats. So now, nene gooses are endangered.

Protecting Biodiversity  Three successful approaches to protecting biodiversity are captive breeding, laws and treaties, and habitat preservation.  Captive breeding is the mating of animals in zoos or wildlife preserves.  Laws can help protect individual species. In U.S.,the Endangered Species Act Prohibits trade in products made from threatened or endangered species.  Protecting whole ecosystems saves not only endangered species, but also the species they depend upon and those that depend upon them.