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Ecology: The scientific study of interactions among organisms and between organisms and their environment.
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Biotic Factors Living organisms Dead organisms Organisms’ waste
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Abiotic Factors Nonliving things in an ecosystem Ex.: Rocks, water, temperature, sunlight, oxygen, sand, climate
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Biodiversity The number of different species in an area
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Climate average weather conditions in an area over a long period of time determines kinds of species present
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Climatograph
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Abiotic factors affect biodiversity Temperature: very high or very low temp. limits biodiversity Water: amount limits biodiversity
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Is high or low biodiversity better?
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High biodiversity resists damage better! Ecosystem damage can come from –natural disasters (fire, flood, volcanic eruptions) –human impact
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Human activities can lead to Habitat Destruction
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Habitat The place where an organism lives
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Competition Species sharing limited resources must compete
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Invasive Exotic Species Species not native to a particular region. Can outcompete or prey on native species, threatening their survival Zebra mussels in Great Lakes
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Kudzu in Alabama
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Nutria in the Louisiana
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Sericea lespedeza in Kansas
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Cane Toads in Australia
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Levels of Organization Species Population Community Ecosystem Biome Biosphere
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Species: organisms that can breed and produce viable offspring.
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Population: individuals of the same species in the same area.
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Community: all populations of different species living together.
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Ecosystem: all organisms in an area and their abiotic environment.
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Biome: a region with specific communities and climate (temp. and precipitation).
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Evolution: Process by which species change over time. Descent with Modification
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Charles Darwin 1809-1882 English Naturalist HMS Beagle 1831-1836 Sailed around world gathering specimens and fossils and observing geology
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Galapagos Islands
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Darwin found unique animals Marine iguana Many other species that live no other place on earth.
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Galapagos Island Finches
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Darwin noticed that the finches on different islands were slightly different: Different beaks Different diets
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Galapagos Tortoises Darwin noticed that the giant tortoises on different islands had different characteristic. How would Lamarck explain these differences? Galapagos tortoise closeup!
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Why are the animals different? Each island has slightly different weather: lower islands are barren and dry, higher islands are wetter So, different islands have different vegetation, different habitat.
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Tortoises with longer necks could reach the higher vegetation in drier areas, so they survived and reproduced, passing their long-necked genes to their offspring. Tortoises in wetter areas had plenty to eat and didn’t need long necks to survive and reproduce. Galapagos tortoise
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Natural Selection: Individuals that have traits better suited to their environment are more likely to survive and reproduce. “survival of the fittest” http://www.uri.edu/cels/nrs/paton/spring_peeper/ sppe_camoflage2.JPG
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Darwin’s steps of natural selection : Variation –inherited variation in every population Overproduction – populations produce more offspring than can possibly survive (leads to competition for resources!) Selection – individuals with favorable traits leave more offspring Adaptation – over time, favorable traits become more common in a population
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Evolution: A change in an inherited characteristic of a population over time. Individuals DO NOT evolve!
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Adaptation: An Inherited trait present in a population because it helps individuals survive AND reproduce in a given environment. Individuals may have adaptations, but they DO NOT CREATE adaptations through use. (That’s Loser Lamarck!)
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Macroevolution (forming new species) is a slowww process! It takes many generations to develop adaptations!!!
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Microevolution is a change in the gene frequencies of a population. Can happen quickly Ex: antibiotic resistant bacterial colonies
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Coevolution Two species develop adaptations in response to one another Disea nivea Orchid and fly
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Darwin’s Artificial Selection When breeding livestock, humans choose the parents with traits they want in the offspring. Ex: dogs, cows, horses, pigeons
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Resistance The ability of an organism to tolerate a particular chemical designed to kill it. Ex: pesticide resistance
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Terrestrial Biomes Tropical - low latitudes, warm, water varies –rain forests - lots of rain –savannas - less rain, long dry season –deserts - little rain, lower biodiversity –http://www.bbc.co.uk/learningzone/clips/imag es-of-a-tropical-biome/3205.htmlhttp://www.bbc.co.uk/learningzone/clips/imag es-of-a-tropical-biome/3205.html
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Temperate - mid-latitudes, temp. varies grasslands - moderate water, cooler temps than savannas forests - plenty of rain, mild climate deserts - little rain, wide temp. range
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High Latitude –taiga - forests in cold, wet climates –tundra - little rain, mostly frozen http://www.bing.com/images/search?q=taiga&form=QBIR&qs=n&sk=&sc=8- 5#focal=21f2731d29856171ea9611a8694e4371&furl=http%3A%2F%2Fwww.johndrew.com%2FAlaska%2520Image s%2FTundra%2520Approaching%2520the%2520Alaska%2520Range1.jpg
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Aquatic Ecosystems Freshwater - lakes, ponds, rivers Wetlands - mix of land/water Estuary - fresh meets salt water Marine - salty water
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Biosphere: the part of the world in which life can exist
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Ecological Methods Observing – what, how many, what are they doing? Experimenting – test hypothesis Modeling – large problems or long time frames.
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