Transcript Biology
Biology Chapter 5.1 Biodiversity Quick Review • Name 3 ways populations are dispersed. – Uniform, clumped, or randomly • What are two ways to keep populations from growing too big, or bringing population size down. – Density-independent factors • Weather events; tornados, earthquake, tsunamis, droughts, – Density-dependent factors • Disease, predidation (one species killing another), parasites, and competition. I can… • Describe three types of biodiversity. • Summarize the direct and indirect value of biodiversity. • Explain the importance of biodiversity. • Imagine all the sudden all the rabbits on earth died. • What do you think would happen? Would it matter? • Extinction: the disappearance of a species from the biosphere through death. – When a species dies, the health of the biosphere reduces. • Biodiversity: The variety of life in an area, which is determined by the number of different species in an area. – Increases the health of the biosphere and stability of an ecosystem. Three types of Biodiversity • Genetic diversity • Species diversity • Ecosystem diversity Genetic Diversity • The variety of genes or inheritable characteristics that are present in a population. – The different colors of rabbits – A specific color may keep the rabbit safe from predators. – Interbreeding (breeding with a different race or species) can increase a species chance of survival. Species Diversity • The number of different species and the relative abundance of each species in a biological community – Species diversity isn’t equal across the biosphere. There are more of a variety of species in tropical zones than in arctic zones. Ecosystem Diversity • The variety of ecosystems that are present in the biosphere. – The different abiotic and biotic factors in an ecosystem and how species interact in an ecosystem is an example of ecosystem diversity. The Importance of Biodiversity • Why preserve biodiversity? – Direct Economic Value: provides plants and animals that give us food, clothing, medicine, and shelter. • Even those species we don’t use are important to the health of species we do. • May need genes from species we don’t use for those we do. For example, Teosinte is a relative of corn. It can withstand viral diseases that kill corn. The gene that resists disease was used to engineer corn that can now resists disease. • These combining of genes is called genetic engineering. • Indirect economic values: different plants and animals provide us with many important resources. – Oxygen, clean water, nutrients, fertile soil, • Aesthetic value: aesthetic means the beauty. Can we put a value on how a beautiful a grove of trees in the fall are, or the sun shining on a clear lake? • Scientific value: Can we put a value on studying something?