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4.1.1 Biodiversity

Explore the concepts of biodiversity and evolution, including genetic diversity, species diversity, and habitat diversity. Understand the significance of biodiversity in ecosystems and its impact on human life. Discover ecological services provided by biodiversity and the importance of natural selection in species evolution.

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4.1.1 Biodiversity

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  1. 4.1.1 Biodiversity

  2. Important Terms • Biodiversity: The amount of different species living in an area. • Genetic Diversity: Different genetic characteristics of a species. • Cheetah populations have very low diversity, due to inbreeding

  3. Important Terms • Species Diversity: The number of species or organisms per unit area found in different habitats of the planet.

  4. Important Terms • Habitat Diversity: The amount of habitats or niches in a given area • Variety of forests, deserts, grasslands, lakes, oceans, coral reefs, wet lands, and other biological communities. Chaparral Coniferous forest dessert grasslands deciduous forest

  5. Biodiversity: Why should we care? • Diverse ecosystems are more stable and more healthy • More resistant to damage from factors like climate change and spread of disease • Provides important ecological services to humans • Biodiversity is useful to us as humans • Recreation • Food • Goods • Medicine

  6. Pre-Assessment Questions(Write on Loose leaf paper) • How do you think diversity changes during succession? • Do you think a more complex ecosystem is more or less stable? • How could human activities (agriculture, mining…) impact biodiversity? • What are the potential positive and negative results of human activities that reduce diversity? • How might habitat diversity impact species diversity and genetic diversity?

  7. Ecological Services of Biodiversity • Flow of material, energy in the biosphere • Photosynthesis • Pollination • Soil formation and maintenance • Nutrient cycling • Moderation of weather extremes • Purification of air and water

  8. Important “stuff” From biodiversity • Food, fuel, ecosystems, species, fiber, lumber, paper…. • 90% of all food crops • 40% of all medicines and 85% of all antibiotics Pacific Yew – Taxol (cancer drug) Willow Tree - Aspirin

  9. Biodiversity of Species

  10. 4.1.2-.5 Natural Selection

  11. Darwin Natural Selection • Important Terms • Evolution: A change in the gene pool of a population over time • Natural Selection: Process by which individuals that are better suited to their environment survive and reproduce more successfully. • Adaptation: An inherited characteristic that increases an organism’s chance of survival.

  12. Darwin's Research • Studies 13 species of finches on Galapagos Islands • Looked a beak size and shape: • Stout beaks for eating seeds • Short and sharp beaks for eating insects. • Woodpecker-like beak for eating insects from trees, but instead of a long tongue it uses a cactus spine held in its beak to remove its prey.

  13. Darwin’s Finches

  14. Darwin’s Theory • Based on his observations he proposed that the evolution of species occurs by Natural selection. • Occurred due to: • Variation within populations (Genetic Diversity) • Overproduction of offspring (J and S curves) • Struggle for existence (Competition/ Limited resources) • Unequal survival and reproduction rates (R and K)

  15. Population of Organisms Overproduction of Offspring Mutations & Sexual Reproduction produces variations among offspring. Limited resources leads to a struggle for survival between offspring. Survivors reproduce more successfully. Population changes over time.

  16. What is a species? • Species: A group of interbreeding populations, with a common gene pool, which are reproductively isolated. • It’s not all about looks! Different Species: They do not Interbreed, because they have different songs. Western Medowlark Eastern Medowlark

  17. What is a species… • Species definition was made by humans, and fails to fully define nature. • These two ants look different are the same species of ant fulfilling different roles in a colony. Pheidole barbata

  18. Species definition is not always black and whiteAre we the same? +

  19. ZONKEY

  20. Are we the same? +

  21. LIGER!

  22. Speciation due to isolation • The islands are close enough to allow migration and cause distinct island populations to arise. • But the distances between the islands is great enough to reduce interbreeding between islands • This has made possible the formation of distinctive species on the islands Speciation in grand canyon

  23. Speciation of salamanders due to geographic isolation

  24. Speciation occurred on the earth over a very long period of time when the continents slowly drifted apart. This leads to geographic isolation Continental Drift Animation

  25. Process of Natural Selection • Organisms became isolated on various continents which restricted interbreeding populations • Without the opportunity to interbreed and the slowly changing climatic conditions organisms “evolve” into a new species over time. • This leads to “survival of the fittest” • Fitness: Organisms that are better suited to survive and reproduce

  26. Discussion Question • Why does Australia have such strange animals??

  27. Evolutionary Timeline of mammals Platypus (Monotreme) Dingo (Placental Mammal) Kangaroo (Marsupial)

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