Species Diversity

1. Species Diversity LT 3D: Describe the role species diversity plays in ecosystems.

2. Geologic Processes and Biodiversity • Tectonic plates: huge flows of molten rock within the earth’s interior that break its surface into a series of gigantic solid plates • Have drifted slowly over the earth’s mantle for hundreds of years

3. Geologic Processes and Biodiversity

4. Geologic Processes and Biodiversity • Tectonic drift has had two important effects on distribution of life: • Locations (latitudes) of continental and oceanic basins have greatly influenced the earth’s climate • Allowed species to adapt to new environments and form new species through natural selection

5. Geologic Processes and Biodiversity • Continental movement can occur in two main ways • Come together  often leads to spread of diversity • Split apart  can lead to species extinction. Think Box: How do you think that an area of land splitting apart could cause the extinction of a species?

6. Speciation and Biodiversity • Speciation: process by which one or more species splits into tow or more different species. Occurs in two phases: • Geographic Isolation: different groups of the same population become physically isolated from one another for a large period of time. • Reproductive Isolation: mutation and change by natural selection operate independently in the gene pools of geographically isolated populations.

7. Speciation and Biodiversity

8. Extinction and Biodiversity • Extinction: A process in which an entire species ceases to exist. • Endemic species: Species that are especially vulnerable to extinction because they are found in only one area. • http://www.cnn.com/video/?/video/world/2010/04/22/romo.earth.day.costa.rica.cnn#/video/world/2010/04/22/romo.earth.day.costa.rica.cnn

9. Species Diversity Think Box: Which of these two ecosystems do you think is most diverse? Explain

10. Niche • Ecological Niche: Each species has a specific role to play in the ecosystems where it is found • Includes everything that affects survival and reproduction of a species • Ex: water, sunlight, what it feeds on, what feeds on it, and temperatures it can tolerate

11. Types of Species • Generalist species: Have broad niches • Can live in many different places • Eat a variety of food • Tolerate a wide range of environmental conditions • Ex:

12. Types of Species • Specialist Species: occupy narrow niches • Live in only one type of habitat • Use just one or only a few types of food • Tolerate a narrow range of climatic or environmental conditions • Ex

13. Think Box • Which do you think is more prone to extinction, the generalist or the specialist? Why?

14. Roles of Species • Native species: species that normally live and thrive in a particular ecosystem. • Non-native species species that migrate into, or are deliberately or accidently introduced into an ecosystem.

15. Roles of Species

16. Roles of Species • Indicator species: provide early warnings of damage to a community or ecosystem. • http://vimeo.com/groups/conservation/videos/16839012 • Explain how the organisms in this video acted as indicator species.

17. Roles of Species • Keystone species: Species whose roles have a large effect on the types and abundance of other species in an ecosystem. • Ex: The American Alligator • Eat large numbers of gar, a predatory fish, which helps to maintain populations of game fish that gar like to eat

18. Role of Species • Foundation Species: Species that play a major role in shaping their species by creating and enhancing their habitats in ways that benefit other species. • Ex: Beavers: act as ecological engineers by building dams in streams to create wetlands and ponds that they and other species use.

19. Think Box • What is the difference between keystone species and foundation species?