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Chapter 4. Ecosystems and Living Organisms. What was the situation of the gray wolves before their introduction? After their introduction in 1995?. Evolution. Overproduction. Variation. Struggle for existence. Differential reproductive success.
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Chapter 4 Ecosystems and Living Organisms What was the situation of the gray wolves before their introduction? After their introduction in 1995?
Evolution Overproduction Variation Struggle for existence Differential reproductive success • Evolution - Genetic changes in a population through time. • Occurs through the process of Natural Selection.
Evolution • Darwin’s Finches What evidence supports evolution?
Evolution What is the difference between prokaryotes and eukaryotes? • Kingdoms of Life - • Why Classify?
Biological Communities How are communities nested within one another? • What is a community? • Rotting Log Community
Biological Communities Rocks Lichens Mosses • Succession: • How Communities Change over Time • Primary succession –
Biological Communities Grasses Shrubs • Succession: How Communities Change over Time • Primary succession – Rocks Lichens Mosses
Biological Communities Grasses Shrubs Trees • Succession: How Communities Change over Time • Primary succession – Rocks Lichens Mosses
Biological Communities • Secondary Succession How does primary succession differ from secondary succession?
Interactions Among Organisms • Symbiosis – • one species living in or on another species • results from coevolution How have pollinators and pollinating coevoled?
Interactions Among Organisms With mycorrhizae Without mycorrhizae • Symbiosis – • Three types 1) Mutualism
Interactions Among Organisms Epiphytes 2) Commensalism
Interactions Among Organisms Tracheal mites - found in the breathing tubes of honeybees 3) Parasitism Why have wild and domestic honeybees in the United States been dying off? What is a solution?
Interactions Among Organisms • Predation – predators consuming prey • Most common method:Pursuit and Ambush
Interactions Among Organisms • Defenses against predators: • Plant defenses – • spines, thorns • leathery leaves • toxic chemicals
Interactions Among Organisms • Defenses against predators: • Animal defenses – • armor, spines • toxic chemicals • camouflage
Interactions Among Organisms • Competition – • individuals attempting to utilize common resources • Intraspecific competition • Interspecific competition What is the difference between habitat and niche?
The Ecological Niche Green Anole Brown Anole • An organism’s adaptations, use of resources, lifestyle, and habitat. • Fundamental vs. Realized Niche • Example: Tale of Two Anoles
The Ecological Niche Fundamental Niche of Green Anole Fundamental Niche of Brown Anole • Fundamental vs. Realized Niche Overlap Brown anole out-competes green anole, therefore . . .
The Ecological Niche Realized Niche of Green Anole Realized Niche of Brown Anole • Fundamental vs. Realized Niche Overlap
The Ecological Niche What are examples of limiting resources? • Limiting Resources
The Ecological Niche • Competitive Exclusion
The Ecological Niche • Competitive Exclusion
The Ecological Niche • Competitive Exclusion
The Ecological Niche • Resource partitioning
Keystone Species • Single species that strongly influences an entire community. • Example: figs • - fruit-eating vertebrates depend upon fruit • - usually avoid figs, but during certain times of the year, figs are only species bearing fruit • - if figs were eliminated, many frugivores would die out
Species Richness • Number of different species in a community How is the structural complexity of vegetation defined? What conclusion can you make based on this graph?
Species Richness What factors can determine the species richness in an area? Forest Grassland ECOTONE Where edge effect occurs Why is there greater species diversity in this area?
Species Richness Ecosystem services Ecosystem • Species Richness and Ecosystem Services Purify air / water Forests,Grasslands Produce / maintain soil Absorb CO2 Wildlife habitat Freshwater systems Moderate water flow Mitigate flooding Dilute / remove pollutants Drinking water Recreation
Species Richness • Species Richness and Community Stability • Greater the richness = Greater the stability • What happened and continues to happen in Lake Victoria?