Slide 1 / 125 Slide 2 / 125 New Jersey Center for Teaching and Learning Progressive Science Initiative AP BIOLOGY This material is made freely available at www.njctl.org and is intended for the non-commercial use of students and teachers. These materials may not be Big Idea 2 used for any commercial purpose without the written permission of the owners. NJCTL maintains its Part E website for the convenience of teachers who wish to make their work available to other teachers, participate in a virtual professional learning community, and/or provide access to course January 2013 materials to parents, students and others. www.njctl.org Click to go to website: www.njctl.org Slide 3 / 125 Slide 4 / 125 Big Idea 2: Part E Evolution of Ecosystems Click on the topic to go to that section · Evolution of Ecosystems · Implications of Ecological Evolution · The Evolution of Bioenergetics Return to Table of Contents Slide 5 / 125 Slide 6 / 125 Primary Succession Where Did it All Come From? We just surveyed the levels of life from population to Primary succession refers to the founding of new biosphere and saw that the basis for an ecosystem is the communities in environments that initially had no way in which energy is passed from life form to life form. living organisms, like rocks or new surfaces formed by movements of glaciers or volcanic eruptions. But how does such a system evolve? As with all systems that evolve it starts simply and increasing layers of complexity are added.
Slide 7 / 125 Slide 8 / 125 Primary Succession Primary Succession What would have to be the first step to producing a Before we could guess as to what specific organisms community in this sterile environment? Who would be would be able to inhabit this area we would need to the first inhabitants? know about the climate of this region and the resources available. The abiotic dictates the biotic . Autotrophs: Plants or Algae or some other organism capable of producing sugar. Slide 9 / 125 Slide 10 / 125 Ecological Succession Pioneer Species In primary ecological succession, the first organisms to populate an uninhabited environment are called the Ecological succession is the term used to describe the pioneer species . series of expected changes that occur within the community of an ecosystem over time. A good example is lichen - an organism formed by a symbiotic relationship between fungi and algae that can Change is inevitable within communities - older members grow on rocks. die, new organisms immigrate, sudden disturbances force change, etc. Lichens begin growing on the rock. As they die, the decaying matter is added to the eroding rock and the start of nutrient rich soil begins. Slide 11 / 125 Slide 12 / 125 Pioneer Species Pioneer Species Carnivores and omnivores can now move into the area to feed on Lichens act as a foothold for species like moss and they begin the small herbivores. The random chance process that leads to each new animal adds to the diversity of the area. A food web growing on the rock. The first heterotrophic animal life can begin to begins to form and habitats are defined. move into the area because small worms and caterpillar like creatures eat moss. As the mosses die, the decaying matter is added to the rock, producing thicker soil.
Slide 13 / 125 Slide 14 / 125 Primary Succession Habitat The term habitat describes the specific area - including biotic and Nutrients supplied by decaying organic matter support the abiotic factors - where an organism lives within an ecosystem. A growth of grasses and small plants. These add more organic habitat is an organism's home within an ecosystem. nutrients, which form deeper more fertile soil. Slide 15 / 125 Slide 16 / 125 Primary Succession Primary Succession The bigger producers attract bigger primary consumers. The larger herbivore brings larger carnivores and the complexity of the food web continues to grow. Slide 17 / 125 Slide 18 / 125 Primary Succession Climax Communities Finally, larger trees can grow, and climax communities As deeper soils formed by decaying organic matter form. Climax communities are groups of organisms that hold more water, small shrubs begin to grow. remain stable in an ecosystem over time. The food web may shift and evolution will continue, but the climax community will remain if no catastrophic event occurs.
Slide 19 / 125 Slide 20 / 125 Climax Communities Community Interactions Inside this community symbiotic relationships will form as evolution continues to act on the ecosystem. Variations will Communities interact in a variety of different ways that enable the give advantage to some plants or herbivores or carnivores organisms within them to establish a niche and shape the and the balance of inhabitants will shift. ecosystem in which they live. The following are types of interactions within communities: Competition Predation Mutualism Symbiosis Commensalism Parasitism Slide 21 / 125 Slide 22 / 125 Competition Predation When organisms try to obtain food, Predation occurs when one organism captures and feeds on water, space, sunlight, and other other organisms. The organism doing the eating is the resources in the same place at the predator and the organism being eaten is the prey . same time, competition occurs. Competition in nature drives biological evolution. The ability to compete for resources is dependent upon whether an organism has adaptations that enable it to thrive in its environment. Great white shark Ladybird beetle capturing prey Trees in this forest are in competition for light. The tall, broad-leafed eating aphid trees outcompete the smaller trees for sunlight. Cheetah stalking gazelle Slide 23 / 125 Slide 24 / 125 Symbiosis Predation and Co-evolution The term symbiosis means "living together." When two species live closely together they are said to be in a symbiotic Predation is a driving factor in co-evolution. The prey evolves to relationship. better escape the predator. In turn the predator evolves to better capture the prey. There are three main categories of symbiotic relationships: Mutualism Commensalism Parasitism
Slide 25 / 125 Slide 26 / 125 Commensalism Mutualism In commensalism , one species benefits from the relationship while the other is neither helped nor harmed by it. In mutualism , both species benefit from the relationship. In this example, the flower provides the hummingbird with nectar and the hummingbird helps the flower reproduce by transporting pollen from one flower to the next. Barnacles attach to the whale and The bird gets a free ride help themselves to small amounts from the cow and a vantage Mutualism: a win/win situation of plankton (whale food) with no point for spotting prey. harm done to the whale. Commensalism: a win/neutral situation Slide 27 / 125 Slide 28 / 125 Parasitism 1 Tapeworms live in the intestines of mammals and "steal" nutrients from them. This is an example of In parasitism , one organism lives on or inside another organism and harms it. A Competition B Mutualism Parasites are organisms that obtain all or most of their nutrients from other organisms, called hosts. The host-parasite C Commensalism relationship benefits the parasite at the cost of the host. D Parasitism Mosquitoes feed off of the blood of other organisms. Mosquitoes also carry various types of parasites and viruses that cause diseases like yellow fever and malaria. Parasitism: a win/lose situation Slide 29 / 125 Slide 30 / 125 2E. coli live in the human colon where they absorb nutrients and 3A relationship in which one organism is helped and another produce vitamin K and sodium that benefit their human hosts. organism is neither helped nor hurt is called This is an example of A Competition A Competition B Mutualism B Mutualism C Commensalism C Commensalism D Parasitism D Parasitism
Slide 31 / 125 Slide 32 / 125 4Which of the following types of community interactions leads to coevolution? Implications of Ecological Evolution A Predation B Mutualism C Parasitism D All of the above Return to Table of Contents Slide 33 / 125 Slide 34 / 125 Ecosystems Implication of Ecological Evolution As we have just seen, ecological systems arise by evolution. This means that the organisms that live within Ecosystems are the each ecosystem have adapted to the specific climate and functional units of the conditions of their habitat. biosphere. Any changes, especially sudden changes can be Healthy, productive detrimental to the health of the ecosystem residence. ecosystems result in a healthy planet. Slide 35 / 125 Slide 36 / 125 Ecosystem Productivity Available Reproductive Energy The primary productivity of an ecosystem The balance of carrying capacity is established by the is measured by the rate at which organic ecological residences' rate of reproduction. matter is created by producers. Reproduction and raising offspring requires free energy Biomass is the total amount of beyond that used for maintenance and growth. For some living tissue (organic matter) species this may be very high. within a given trophic level. The energy available within an ecosystem dictates how Productive ecosystems have many offspring any given species can produce. Different an optimal balance of organisms use various reproductive strategies in response to biomass in each energy availability. trophic level.
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