1	Levels of Biological Organization Organ system Multicellular organism Population Community Ecosystem Biosphere
2	Population A group of individuals of the same species living in the same area Population Characteristics Size number of individuals (gene pool) Age Structure Distribution in the environment
3	Characteristics of Populations Size Density Distribution Age Structures Life Histories Strategies
4	Density The number of individuals in a given area or volume of a habitat Crude Density number per unit area Ecological Density number per area of ‘useable’ habitat resources and energy flow
5	Three Patterns of Dispersion
6	Nearly Uniform
7	Clumped
8	Age Structure populations characterized by specific age categories Often separated by reproductive potential Pre-reproductive Eggs, Larvae Reproductive Adults Post-reproductive Or Size classes seedling young mature ancient usually DBH for trees
9	Population Size Regulation New members (Increases) births immigration Members removed (Decreases) death emigration Migration Net =0
10	Exponential Growth J-shaped curve Larger ‘r’ values Unlimited Resources N= e^rt
11	Exponential Movie
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14	Limiting Factors Nutrient supply Competition for space Predatation Parasitism Disease Weather
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20	Strategies r strategists short-lived ‘relatively’ early reproduction rapid development smaller size large numbers of offspring little parental care Disturbed habitats/ ephemeral habitats Good colonizers “weedy species”
21	Strategies k strategists delayed reproduction fewer offspring slower development larger body sizes high parental investment lower mortality Stable habitats Good competitors
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24	Species Interactions Neutral Symbiotic Competition Predation/Parasitism
25	Symbiosis Commensalism one benefits Mutualism both benefit Parasitism one benefits one is reduced
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27	Species Interactions
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29	Interspecific Competition Principle of competitive exclusion GF Gauss For 2 species competing for the same resources, 1 will survive, the other will be driven to extinction
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31	Resource Partitioning
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35	Defenses Physical structures Horns, antlers, shells, thorns
36	Defenses Physical structures Chemicals Skunks, garter snakes – smell Ants – taste Toxins ex. poison oak, milkweed
37	Defenses Physical structures Chemicals
38	Defenses Physical structures Chemicals Coloration Camouflage
39	Defenses Physical structures Chemicals Coloration Camouflage
40	Defenses Physical structures Chemicals Coloration Warning
41	Defenses Physical structures Chemicals Coloration Mimicry
42	Defenses Physical structures Chemicals Coloration Mimicry
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45	Primary Succession Starts from scratch Soil needs to be formed
46	Secondary Succession Starts with soil Recovery from disturbances (Fire)
47	Biodiversity Why are there so many species?
48	Class Discussion