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Biodiversity and Evolution Review • Biodiversity includes these components: – Functional diversity – Ecological diversity – Species diversity - Genetic diversity Functional Diversity • The variety of processes, including matter cycling and energy flow within ecosystems, that result from species interacting with one another in food webs Ecological Diversity • Variety of terrestrial and aquatic ecosystems found in an area or on the earth Species Diversity • The number and abundance of species present in different communities Genetic Diversity • The diversity that enables life on earth to adapt and survive environmental changes Natural Selection • Occurs when some individuals of a population have genetically based traits that enhance their ability to survive and produce offspring with the same traits. Evolution • A change in the genetic characteristics of a population from one generation to another Mutations • Random changes in the structure or number of DNA molecules in a cell that can be inherited by offspring. Evolution by Natural Selection Review • Genes mutate, individuals are selected, and populations evolve that are better adapted to survive and reproduce under existing environmental conditions. Human Success • Strong opposable thumbs • Upright walking • Complex brain Survival of the Strongest • Fitness – a measure of reproductive success Geological Processes • • • • • • • Volcanoes Earthquakes Mountains forming Fragmentation of forests Deforestation Construction Etc. Extinction • • • • Entire species cease to exist Endemic species are found in only one area This makes them very vulnerable Mass extinction is a significant rise in extinction rates above the background level • Large groups of species Species Diversity • Species richness – the number of different species vs… • Species evenness - relative abundance of individuals within each species • Higher the richness; the more sustainability Ecological Niche • The role a species plays in its ecosystem • Don’t confuse with the species habitat • Pattern of living General vs. Specific • Generalists have a broad niche • Specialists have a narrow niche Important Niche Roles • Native species – thrive in a particular ecosystem; equilibrium • Indicator species – provide early warning signs of damage • Keystone species – large effect on types and abundance of other species • Foundation species – shape and enhance habitats that benefit other species