1 / 31

Chapter 4 Ecosystems and Living Organisms

Chapter 4 Ecosystems and Living Organisms. Overview of Chapter 4. Evolution Natural Selection Domains and Kingdoms Biological Communities Primary & Secondary Succession Symbiosis Mutualism, Commensalism, Parasitism Predation & Competition Resource Partitioning Keystone Species

mea
Download Presentation

Chapter 4 Ecosystems and Living Organisms

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chapter 4Ecosystems and Living Organisms

  2. Overview of Chapter 4 • Evolution • Natural Selection • Domains and Kingdoms • Biological Communities • Primary & Secondary Succession • Symbiosis • Mutualism, Commensalism, Parasitism • Predation & Competition • Resource Partitioning • Keystone Species • Species Richness & Community Stability

  3. Evolution • The cumulative genetic changes that occur in a population of organisms over time • Current theories were proposed by Charles Darwin, a 19th century naturalist • Evolution occurs through natural selection • Natural Selection • Individuals with more favorable genetic traits are more likely to survive and reproduce • Frequency of favorable traits increase in subsequent generations

  4. Natural Selection • Based on four observations about the natural world • Overproduction • Each species produces more offspring than will survive to maturity • Variation • Individuals in a population exhibit variation • Limits on Population Growth • Resource limitations will keep population in check • Differential Reproductive Success • Individuals with most favorable traits are more likely to reproduce

  5. Natural Selection • Darwin’s finches exemplified the variation associated with natural selection

  6. Domains and Kingdoms of Life

  7. Biological Communities • Communities vary greatly in size and lack precise boundaries • They are often nestled within each other

  8. Succession • The process where a community develops slowly through a series of species • Earlier species alter the environment in some way to make it more habitable by other species • As more species arrive, the earlier species are outcompeted and replaced • Two types of succession • Primary succession • Secondary succession

  9. Primary Succession • Succession that begins in a previously uninhabited environment • No soil is present! • Ex: bare rocks, cooled lava fields, etc. • General Succession Pattern • Lichen secrete acids that crumble the rock (soil begins to form) Lichen mosses grasses shrubs forests

  10. 1 2 • Primary Succession • Bare rock with lichen • Grasses and shrubs • Forest community 3

  11. Secondary Succession • Succession that begins in an environment following destruction of all or part of the earlier community • Ex: abandoned farmland, open area after fire • Does NOT follow primary succession! • Even though name may imply this • Generally occurs more rapidly than primary succession

  12. Secondary Succession of an abandoned farm field in North Carolina

  13. Interactions Among Organisms • Symbiosis • An intimate relationship between members of 2 or more species • Participants may be benefited, harmed or unaffected by the relationship • Results of coevolution is the interdependent evolution of two interacting species. Flowering plants and their animal pollinators have a symbiotic relationship that is an excellent example of coevolution. • Three types of symbiosis • Mutualism • Commensalism • Parasitism

  14. Mutualism • Symbiotic relationship in which both members benefit • Ex: Mycorrihzal fungi and plant roots • Fungus grows around and into roots providing roots with otherwise unavailable nitrogen from soil • Roots provide fungi with food produced by photosynthesis in the plant Left: root growth without fungi Right: root growth with fungi

  15. Commensalism • Symbiotic relationship where one species benefits and the other is neither harmed nor helped • Ex: epiphytes and tropical trees • Epiphytes anchors itself to the tree, but does not take nutrients from the tree • Epiphyte benefits from getting closer to sunlight, tropical tree is not affected

  16. Parasitism • Symbiotic relationship in which one species is benefited and the other is harmed • Parasites rarely kill their hosts • Ex: Varroa mites and honeybees • Mites live in the breathing tubes of the bees, sucking their blood and weakening them

  17. Predation • The consumption of one species by another • Many predator-prey interactions • Most common is pursuit and ambush • Plants and animals have established specific defenses against predation through evolution

  18. Pursuit and Ambush • Pursuing prey simply means chasing it down and catching it • Ex: Day gecko and spider (see picture) • Ambush is when predators catch prey unaware • Camouflage • Attract prey with colors or light

  19. Plant Defenses Against Predation • Plants cannot flee predators • Adaptations • Spikes, thorns, leathery leaves, thick wax • Protective chemicals that are poisonous or unpalatable

  20. Animal Defenses Against Predation • Fleeing or running • Mechanical defenses • Ex: quills of porcupines, shell of turtles • Living in groups • Camouflage • Chemical defenses- poisons • Ex: brightly colored poison arrow frog

  21. Competition • Interaction among organisms that vie for the same resource in an ecosystem • Intraspecific • Competition between individuals in a population • Interspecific • Competition between individuals in 2 different species

  22. Ecological Niche • The totality of an organisms adaptations, its use of resources, and the lifestyle to which it is fitted • Takes into account all aspect of an organisms existence • Physical, chemical, biological factors needed to survive • Habitat • Abiotic components of the environment • Ex: Light, temperature, moisture

  23. Ecological Niche • Fundamental niche • Potential idealized ecological niche • Realized niche • The actual niche the organism occupies • Ex: Green Anole and Brown Anole

  24. Ecological Niche • Green Anole and Brown Anole • Fundamental niches of 2 lizards initially overlapped • Brown anole eventually out-competed the green anole- reduced the green anole’s realized niche

  25. Limiting Resources • Any environmental resource that, because it is scarce or at unfavorable levels, restricts the ecological niche of an organism

  26. Interspecific Competition

  27. Competitive Exclusion & Resource Petitioning • Competitive Exclusion • One species excludes another from a portion of the same niche as a result of competition for resources • Resource Partitioning • Coexisting species’ niche differ from each other in some way

  28. Keystone Species • A species that exerts profound influence on a community • More important to the community than what would be expected based on abundance • The dependence of other species on the keystone species is apparent when the keystone species is removed • Protecting keystone species is a goal to conservation biologists

  29. Species Richness • The number of species in a community • Tropical rainforests = high species richness • Isolated island = low species richness • Related to the abundance of potential ecological niches

  30. Ecosystem Services • Important environmental benefits that ecosystems provide, such as: • Clean air to breathe • Clean water to drink • Fertile soil in which to grow crops

More Related