2 The Changing Environment Humans have only lived on earth for <0.5 million yearsHow old is earth?How did earth form?Earth has been changing since it formedDo you know some ways that earth is changing?Most natural changes are so slow that you don’t see them in a lifetimeSome rapid changes have taken place from human activities
4 Changes in the Lithosphere ***Remember – the lithosphere is the layer of land on earth***The lithosphere is made of several large moveable tectonic platesMolten (liquid) rock from inside earth oozes out through the cracks between the platesThe molten rock hardens (as it cools) pushing apart the plates – this may cause earthquakesMountain chains form when the plates cause the Earth’s surface to buckle
6 Earthquakes:Vibrations caused by the Earth’s crust “slipping” along a fault line (break in the Earth’s crust)Richter Scale – scale used to measureearthquake intensityRanges from 1 – 10(9.5 is most powerful to ever be recorded)Most earthquakes take place on or near faultlinesThe biggest faults are near the boundaries where tectonic plates meetThis is why California has more earthquakes than NJ
9 Volcanoes:A mountain built from magma (melted rock) that rises from the Earth’s interior to its surface.Often located near tectonic plate boundaries.On land or under sea.“Ring of Fire” contains 75% of world’s active volcanoes that are on land.
12 Other Lithospheric Changes Weathering – the breaking down of rock by heat, water, ice, wind, and pressure – no movementErosion – the broken down rock is then carried off by water, wind, ice, and gravity - movement
13 Changes in the Hydrosphere ***Remember – the hydrosphere includes all parts of earth made up of water***As the continents have changed, so have the bodies of waterMost water changes occur slowly and steadily over timeOther water changes occur in a series of cycles:Ice ages – millions of yearsEl Nino – every 4-7 years
14 Ice AgesLong periods of cooling, when glaciers move from poles and cover much of EarthGlaciers - huge masses of ice form calledAfter the ice age, the glaciers retreat back to the polesEvidence of five ice ages in the Earth’s history (most recent ended 12,000 to 10,000 years agoWhen glaciers move, they scrape across earth moving rocks and water to new places
15 El NinoEvery December, a warm, nutrient-poor water current flows southward along the coast of South AmericaNormally this warm current is quickly replaced by a cold, nutrient rich current during an upwellingEvery 4-7 years, the upwelling doesn’t occurThe nutrient poor water cannot support fish life
16 Changes in the Atmosphere Early Earth’s atmosphere was mostly water vapor, carbon dioxide & sulfur from volcanic eruptions.Bacteria evolved that could perform photosynthesis and released first oxygen into atmosphere.For the past 3.5 billion years, the atmosphere consists of recycled nitrogen, oxygen, carbon dioxide & water vapor
17 Changes in the Atmosphere Much of earth’s carbon is cycled through the carbon cycleSome is stored in the bodies of organisms – dead or aliveFossil fuels (coal, natural gas) – formed by breakdown of dead organismsWhen we burn fossil fuels, we release carbon dioxide
18 Greenhouse Effect-release of stored carbon into atmosphere by burning organic matter, which influences the temperature of the Earth.
19 Check for Understanding: 1. Through what process does weather affect the shape of land?2. In what ways does El Nino affect the economy?
20 Needs of OrganismsAn environment should provide an organism with everything it needs to liveEvery organism has a different set of needs and has evolved to fit its environmentAll organisms have certain needs in common:WaterSource of energyLiving spaceSuitable climate
21 WaterFresh water is one of the most important abiotic factors in support of lifePlants need water to growAnimal populations need plants and waterOcean organisms are affected by water qualityWarm water contains less dissolved oxygen than cold water – can’t keep organisms alive
22 Food and EnergyAll energy used by organisms comes from the sun and is stored as foodPlants capture energy from sun and make food through photosynthesisAnimals eat plants and get energyFood contains energy, minerals, and vitaminsNutrients-all the substances that an organism requires from food.
23 Living Space All organisms need space to live and obtain materials Plants need space between them to get sunlight and waterAnimals need space to get food, water, matesTerritory – area claimed as a living space by an individual animal (mark their territory)Size of territory – determined by animalThey will compete till DEATH!
24 ClimateClimate – the temperature and weather that an organism is adapted to live in – it produces varied responses in organismsRange of tolerance – acceptable range of temperature for an organism’s survivalMost organisms’ body temperatures are determined by the environment (cold blooded)Many organisms become dormant to survive cold temperatures
25 ClimateDormant – all metabolic life processes slow down in an organism [ex: plants in winter bacteria in refrigerator]Other organisms (warm blooded) use energy to maintain a high body temperatureWarm blooded animals need 10 X as much food!Some animals also become dormant (hamsters, worms)Hibernation – heart rate and breathing slow, body temperature drops, enters a sleep-like state
26 Hedgehogs: Usually, hedgehogs maintain a constant body temperature, i Hedgehogs: Usually, hedgehogs maintain a constant body temperature, i.e 35 degree centigrade, during summer but at the onset of winter, their temperature drops to 6 degree centigrade in order to cope with the scarcity of food. Hedgehogs go into hibernation for about 2 to 5 months with the males hibernating before the females.
27 Badgers: They are torpors or temporary hibernators and in winters they store enough food in their burrows, so that they may wake up, eat and go back to sleep again. Badgers are omnivores, that is they eat both plants and animals. Honey badgers, one of the types of badgers are nocturnal animals.
28 Frogs and Toads: Frogs living in colder climates, hibernate in winter in small creeks, cracks in logs and in rocky places. They store glucose in their bodies that keeps them from getting frozen. Some of the species of frogs even hibernate under water. Toads are cold blooded and nocturnal creatures. Their hibernation period begins from October and some toads are known to hibernate for as long as three to four years. They survive on body fat that has been stored in their bodies during the warm months.
29 Moths: Moths are a species of insects that closely resemble a butterfly. Moths hibernate in clusters and during the winters they sleep in creeks or cracks in the wood.
30 Check for Understanding: 1. In what ways does the behavior among territorial animals differ?2. How does hibernation help animals to survive?3. Do you think that the amount of water used by each person in the United States has changed over time? If so, in what way? Explain your answer.4. Suppose a particular area was to experience a sudden change in rainfall and temperature that lasts a long time. Do you think the area would lose its ability to support life?
31 The Mississippi Flood Read page 41 in your textbook “The Mississippi Flood – Who should pay for property damage on a floodplain?”Answer the decision questions fully and hand in.
32 The EcosystemEcosystem is a highly organized, structured environment that is delicately balancedEcosystems can be studied on many levels, from individual species to the interactions within the entire ecosystem.Includes all the biotic and abiotic factors in an area.
33 SpeciesA group of organisms similar to one another, able to breed and produce fertile offspringAll members have similar needsRange of toleranceSize of territoryType of foodMembers often compete with each other for resources
34 Habitat The type of environment in which a particular species lives Describe the habitat of a birdDescribe the habitat of a fishDescribe the habitat of a pandaProvides appropriate food, shelter, temperature, etc that a species needs for survivalDestruction of habitat is a serious threat to the survival of many species
35 Geographical Range The total area in which a species can live Depends on the size of the area where the habitat is suitableMountain LionRequires habitat with diverse plants, large hunting territory, variety of prey animalsUsed to roam all of continental U.S.Humans took over their rangeNow restricted to western mountains
36 Populations and Communities Population - all the members of a species that live in the same areaFor example:Ants in an ant hillDandelions in a fieldCommunity - all the populations that live and interact in the same environmentFoe example:The ants and the dandelions
37 EcosystemIncludes all the communities that live in area as well as the abiotic factors in that environmentInclude water, soil, climateHealthy ecosystem contains a wide variety of organisms
38 Biodiversity The variety of species in an environment If enough of a habitat is destroyed, the species that live there can become extinctThis decreases biodiversity and stabilityFor example – tropical rainforests
39 Check for Understanding: 1. What factors are included in an ecosystem?2. What do you think is the geographical range for human beings?3. Some ancient cultures, such as the societies that live in rain forests, are shrinking as a result of the destruction of their habitat. Do you think human societies should be protected, as are endangered species of plants and animals? Explain.