Conservation+and+Biodiversity

__**4.1 Biodiversity in ecosystems**__ There are three kinds of biodiversity: species diversity, the genetic diversity, and the habitat diversity. Species diversity is the most commonly referred to.

Species biodiversity is a measure of both the number of species in an area and their relative abundance. Species diversity arises through adaptations to differing environments, and the need for each species to avoid competition by finding it's own ecological niche **//(an ecological niche is the unique way that a species survives)//**

Darwin's theory of natural selection states that over time a species becomes better adapted to its environment. This occurs because only the 'fittest or better adapted' survive and reproduce, forming the next generation.

Speciation means the formation of new species. Speciation tends to occur when two groups can no longer breed together and share their genes. They start to separate into different species. Speciation occurs because of: -plate tectonics (eg. islands forming from volcanoes)

Speciation causes biodiversity. Rainforests are the land biome with the highest biodiversity. Coral reefs are the oceanic biome with the highest biodiversity. Biodiversity loss today is a major world issue.

Three factors determining how vulnerable an ecosystem is to a disturbance: -inertia (ability to resist change) -resilience (ability to recover from change) -diversity (number of species and their relative abundance