California Science Content Standards

1. California Science Content Standards Today's lecture and activity will cover the following content standards: 5d)Students know different kinds of organisms may play similar ecological roles in similar biomes. (Grade 6) 5e)Students know the number and types of organisms an ecosystem can support depends on the resources available and on abiotic factors, such as quantities of light and water, a range of temperatures, and soil composition (Grade 6) 7b) Select and use appropriate tools and technology (including calculators, computers, balances, spring scales, microscopes, and binoculars) to perform tests, collect data, and display data. (Grade 6)

2. California Science Content Standards Today’s lecture and activity will cover the following content standards: 7c) Construct appropriate graphs from data and develop qualitative statements about the relationships between variables. (Grade 6) 6a)Students know biodiversity is the sum total of different kinds of organisms and is affected by alterations of habitats. (Grades 9-12)

3. Communities, Ecosystems and Biomes Community: all the populations in a specific area or region. Studies of communities include examining interactions between different species Ecosystem: refers to the biological community and the associated abiotic environment.

4. Biomes Def: major regional complex of plant (and animal) communities; largest scale community types Are identified by climax vegetation, which is influenced by temperature and rainfall

5. Distribution of Biomes

6. Within communities, ecosystems and biomes, scientists are concerned with studying: BIODIVERSITY

7. What is Biodiversity? def: biodiversity = biological diversity = the variety of life and their habitats There are three components: Genetic Diversity Habitat Diversity Species Diversity

8. Losses in Biodiversity Past extinction rates = 2-25 spp./yr. Current extinction rates = up to 10,000+ spp./yr. * past extinctions due to natural phenomena * present extinctions due to human-caused phenomena

9. Genetic Diversity Def: amount of genetic variation present: * within individuals * between individuals within a population * between populations

10. Habitat Diversity Def: variety of ecosystems in an area Includes: * communities * functional properties *physical properties

11. Species Diversity Def: the variety of species in an area Two subcomponents: species richness species evenness

12. Species Richness vs. Evenness Species Richness: measurement of the number of species in a given area Species Evenness: measurement of how evenly distributed organisms are among species Community A Community B species 1 25 1 species 2 0 1 species 3 25 1 species 4 25 1 species 5 25 96

13. Determining Species Diversity Scientists may want to: * get an estimate of # of species in an area * compare species diversity of two communities To be accurate, need to: * take both species evenness and species richness into account

14. Species Diversity Indices Shannon-Weiner (Shannon-Weaver) Index Diversity = (p spp 1 - ln(p spp 1)) + (p spp 2 - ln(p spp. 2) + … (p spp N - ln(p spp. N) Simpson Index Diversity = 1 (pspp1)2 + (pspp2)2 + … (psppN)2

15. Why should we care about measuring biodiversity (species diversity)?

16. Biodiversity Factoids ~ 2,000,000 spp. have been described ~ 10-30,000,000 species actually exist (est.) ~ 8,000,000 – 22,000,000 spp. unidentified ~ 40 – 60% of all spp. occur in two areas: * tropical rainforests * coral reefs

17. Losses in Biodiversity Past extinction rates = 2-25 spp./yr. Current extinction rates = up to 10,000+ spp./yr. * past extinctions due to natural phenomena * present extinctions due to human-caused phenomena

18. Human-Caused Factors of Biodiversity Loss Loss of biodiversity caused by: Introduction of Habitat Destruction Exotic Species

19. Human-Caused Factors of Biodiversity Loss Biodiversity loss caused by: Overharvesting/ Pollution Overhunting

20. Extinction • There have been 5 mass extinction events • during the history of the earth Are we on the verge of a 6th?