1. California Life Science Standards Test Prep. Ecology&Evolution

2. Outline Ecology Ecology Food WebsFood Webs Categorizing PopulationsCategorizing Populations Carrying CapacityCarrying Capacity BiodiversityBiodiversity Changes in EcosystemsChanges in Ecosystems Population SizePopulation Size Abiotic CyclesAbiotic Cycles Producers and DecomposersProducers and Decomposers Energy PyramidEnergy Pyramid

3. Outline Evolution Evolution DiversityDiversity Natural SelectionNatural Selection Theory of EvolutionTheory of Evolution Natural Selection acts on PhenotypesNatural Selection acts on Phenotypes Lethal GenesLethal Genes MutationsMutations Variation & DiversityVariation & Diversity EvidenceEvidence

4. Ecology Food Webs Food Webs show how energy and matter is transferred from one organism to another and the physical environment.

5. Ecology Functions of Organisms

6. Ecology Carrying Capacity Carrying Capacity is the number of each type of organisms that an ecosystem can support. Carrying Capacity is the number of each type of organisms that an ecosystem can support. Depends on: Depends on: Abiotic Factors:Abiotic Factors: Light Light Water Water Temperature Temperature Soil Composition Soil Composition Biotic FactorsBiotic Factors Prey Prey Predators Predators

7. Ecology Biodiversity Biodiversity – the sum total of the different kinds of organisms which is affected by alterations of habitats.

8. Ecology Changes in Ecosystems Ecosystems can be changed by: Ecosystems can be changed by: Climate ChangesClimate Changes Human ActivityHuman Activity Introduction of Non-native speciesIntroduction of Non-native species Changes in population sizeChanges in population size

9. Ecology Population Sizes Population size is affected by: Population size is affected by: Birth Rate (+)Birth Rate (+) Immigration (+)Immigration (+) Emigration (-)Emigration (-) Death Rate (-)Death Rate (-) Population Change = Birth Rate + Immigration – Emigration – Death Rate Population Change = Birth Rate + Immigration – Emigration – Death Rate

10. Ecology Cycles The Carbon Cycle The Water Cycle The Nitrogen Cycle Oxygen / Carbon Dioxide Cycling

11. Ecology Producers & Decomposers Producers – Organisms that convert CO2, water, and energy (sunlight) into organic compounds. [Photosynthesis] (Plants, Phytoplankton) Producers – Organisms that convert CO2, water, and energy (sunlight) into organic compounds. [Photosynthesis] (Plants, Phytoplankton) Decomposers – Organisms that break down complex organic compounds into simple compounds for producers to use. (Bacteria, Fungi, Molds) Decomposers – Organisms that break down complex organic compounds into simple compounds for producers to use. (Bacteria, Fungi, Molds) It is vital that for an ecosystem that there is a stable population of Producers and decomposers. It is vital that for an ecosystem that there is a stable population of Producers and decomposers.

12. Ecology Energy Pyramid At each link in a food web Some energy is stored in newly made structures. Much energy is dissipated into the environment as heat

13. Evolution Diversity Genetic VariationEnvironmental Factors Affect evolution and diversity of organisms

14. Evolution Natural Selection Natural selection is the mechanisms of evolution. Since an environment cannot support all of the organisms that could be produced, only those organisms who have characteristics that allow them to survive and reproduce will. Future generations will tend to have a greater proportion of these characteristics.

15. Evolution Evidence Geology Fossils Comparative Anatomy

16. Evolution Natural Selection Natural Selection acts on the Phenotypes (observable characteristics) rather than Genotypes (genetic combination) of an organism. Environmental conditions can only act on the characteristics that an organism displays.

17. Evolution Lethal Alleles in the Gene Pool Most lethal alleles are recessive. Most lethal alleles are recessive. Only expressed when an individual has two of the recessive alleles (homozygous recessive)Only expressed when an individual has two of the recessive alleles (homozygous recessive) When an individual has a dominant and a recessive (heterozygous), the dominant is expressed. When an individual has a dominant and a recessive (heterozygous), the dominant is expressed. The recessive is hidden by the dominant.The recessive is hidden by the dominant. This allows lethal recessives to be maintained in a gene pool. This allows lethal recessives to be maintained in a gene pool.

18. Evolution Mutations New mutations are constantly being generated in a gene pool. New mutations are constantly being generated in a gene pool. Random mutationsRandom mutations Environmental influencesEnvironmental influences Lethal mutations tend to be eliminated quickly. Lethal mutations tend to be eliminated quickly. Advantageous mutations tend to increase quickly. Advantageous mutations tend to increase quickly. Neutral mutations tend to stay fairly constant. Neutral mutations tend to stay fairly constant.

19. Evolution Variation The more variation there is within a species, the more likely that at least some members will survive under changed environmental conditions. The more variation there is within a species, the more likely that at least some members will survive under changed environmental conditions.

20. Evolution Differential Survival

21. Evolution Diversity The more diversity there is within a geographic area, the more likely that at least some organisms will survive under changed environmental conditions. The more diversity there is within a geographic area, the more likely that at least some organisms will survive under changed environmental conditions.

22. Evolution Fossil Evidence Biological Diversity – Different types of organisms over time. Episodic speciation – New species develop over time. Mass extinction – Periodic episodes of large scale loss of species.