Environmental Science - Lecture notes - dddeco - Lecture Notes, Lecture Chapter 1 - 3, 8 PDF

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Chapter 3 Evolution, Biodiversity, and Population Ecology Biodiversity and Related Terms -

Biodiversity: variety of life across all levels of biological organization Species: members share traits and can produce fertile offspring

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Population: group of individuals of a particular species living in an area

Diversity and Unity of Life -

Diversity in the millions of species of life on Earth, but also unity All life is composed of cells

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ATP is the universal energy currency All life uses DNA as genetic information

Evolution -

Evolution is change over time

Ex: dog breeding - Evolution explains diversity and unity of life -

Common ancestry with divergence over generations

Three Observations 1. Constant struggle to survive and reproduce 2. More offspring are produced than can survive 3. Individuals of a species vary in characteristics

Natural Selection -

Inherited traits that enhance survival and reproduction are passed on

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Mechanism of evolution causing directional change Proposed by Charles Darwin and Alfred Russel Wallace

Genetic Basics -

Evolution occurs at the genetic level

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Gene: region of DNA that codes for a protein Protein: molecules carry on all the work pf life

Ex: structure, speed reactions, transport, defense Gene  Protein  Cell work

Genetic Variation -

Traits must be coded by DNA to be passed on

Ex: eye color, hair color - Variation can be neutral, deadly, or beneficial - Sources of variation: 1. Through mutation (change in DNA) 2. Through sexual reproduction (new combinations of genes)

Environmental conditions -

Determine which traits will be favorable Conditions differ all the time

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Interactions between genes and environment create perpetual process of change

Similar environments can lead to similar traits.

Evidence of Selection -

Selective breeding

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Insecticide resistance Anatomical similarities

Evolution of insecticide resistance in insect populations

Anatomical Similarities

Speciation -

Speciation is the process by which new species are generated

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In allopatric speciation, populations are physical separated Over thousands of generations, each population accumulated its own set of mutations

Allopatric Speciation

History of Life’s Diversification -

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Phylogenetic tress: 1. Show relationships among species 2. Analyze patterns of similarity Fossils: 1. Imprints in stone of dead organisms

Phylogenetic Tree

Fossil Trilobite

Extinction -

Extinction: 1. Disappearance of species from Earth 2. On average, species go extinct in 1-10 million years 3. Most species that have ever lived are now extinct 4. Mass extinction events have occurred

Ecology -

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Ecology: 1. Study of interactions between organisms and their environment 2. Important to understand natural systems as part of environmental science Habitat: 1. Specific environment in which an organism lives 2. Survival depends on availability of suitable habitats

Population Ecology -

Population size: number of individuals present at a given time Population density: 1. Number of individuals per unit area 2. High rates- find mates, but competition and disease

Population Ecology -

Population dispersion: Spatial arrangement of organisms

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Age Structure: relative numbers of each age within population

 Most common

Population Growth -

Growth rate: rate of change in population size over time =(birth rate + immigration) – (death rate + emigration rate)

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Exponential growth : 1. Increases by fixed percentage (r) each year 2. J-shaped growth curve 3. New environments with abundant resources

Limits to Growth -

Limiting factors: constrain population growth 1. Physical, chemical, biological 2. Food, water, mates, shelter, breeding sites, disease, nutrients, light

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Carrying capacity(K): maximum population size that env’t can sustain Logistic growth: initial fast growth is slowed and brought to K

Logistic Growth

Reproductive Strategies -

Along with limiting factors, reproductive strategies also regulate growth

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K- selected species: 1. Few offspring with lots of care 2. Humans, elephant, giraffes

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R-selected species: 1. Lots of small offspring with no parental care 2. Plants, fish, frogs, insects

Golden Toads of Costa Rica -

Found only in Montverde cloud forest

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Documented 1964 Extinct 1990 Worldwide amphibians are declining more than other organisms

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Why? Chytrid fungus Also habitat loss, pollution, climate change

Cool ocean = cloud forests

Warmer Conditions

Conservation Biology -

Studies causes, protection, restoration of biodiversity

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Science and values help us develop solutions

Chapter 1 The Environment- Earth’s living and non-living things.

Ex: Humans

Environment Science- study of how we affects environment and how environment affects us. Natural Resources- energy and substances in environment 1. Renewable-Replenished over a short period of time. Ex: sun, wind. 2. Nonrenewable- formed very slowly, limited or finite amount Ex: oil, gas, coal

Natural Services- ecosystem services as part of normal functioning of natural area. Ex: air and water purification, nutrient cycling pollination

Marine Ecosystem Services

Human Impact- our interactions with the environment around us matter a great deal. - Impact results from: Population, affluence leading to consumption, technology - (IPAT model= impact, population, affluence, technology) Resource Consumption- Global affluence has led to higher consumption of resources Ecological footprint- Amount of land and water needed to sustain a person or population

Technology - Increase impact 1. Dig more minerals 2. Use more fossil fuels 3. Cut down old-growth forests 4. Harvest more fish 1. 2. 3.

Decrease impact Reduce smokestack emissions Harness renewable energy Improved manufacturing efficiency

Sustainable Solutions 1. Environment Science can help us avoid past mistakes 2. Move toward sustainable solutions Sustainability- how all organisms can live well within our one planet

Environment Science is interdisciplinary:

Environment vs. Environmentalism - Environment is a science- objective research - Environmentalism is a social movement dedicated to protecting the natural world Nature of Science 1. Science involves observing and asking questions about the world 2. Tests if ideas are supported by evidence 3. Uses critical thinking (high quality inquiry aimed at reaching a conclusion) 4. Can be applied to address social needs

Scientific Method

Experiment Terms 1. Independent variable- what is manipulated 2. Dependent variable- what is measured 3. Experimental control- natural or un-manipulated condition Scientific Process

Environmental Ethics 1. Ethics involves moral principles or values 2. Tells us how we ought to behave Ex: treat others as what to be treated (golden rule) 3. Can be applied to relationship between humans and surroundings= envt’l ethics Ethical Perspectives

Conservation vs Preservation Preservation: protect env’t pristine, unaltered state. John Muir

Conservation: use natural resources, but with wise management. Gifford Pinchot Environmental Justice- Fair and equitable treatment of all people in relation to environmental policy and practice Ex: nonhuman, poor, or minority groups should not be exposed to greater share of pollution Sustainability 1. Living within our planet ’s means 2. Conserve resources 3. Maintain fully functioning ecosystems 4. Develop long-term solutions

Sustainable solutions: 1. Renewable energy 2. Soil conservation, improved irrigation 3. Reduced pollution from industry and cars 4. Habitat protection 5. Reduce, reuse, recycle Sustainable development: 1. Combination of environmental protection, economic development, social justice 2. ‘’ leapfrogging’’ to sustainable conditions as countries develop 3. Skip intermediate, resource-intensive stages Ex: from no phones to cell phones, skipping poles and landlines Ex: local, small-scale electricity vs. power lines

Chapter 2 Environmental Systems: Matter, Energy, Ecosystems Environmental Systems - Earth has a complex network of interlinked systems: 1. Interactions of organisms 2. Chemical cycling 3. Geological processes - Systems approach is large-scale System Interactions - System components interact and influence one another - Feedback loop: circular process in which output loops back to input - Negative feedback: restores balance to systems - Positive feedback: moves system further to extreme

Boundaries of Systems - People divide env’t into systems to study, but overlap and interact - Also, identifying boundaries of system depends on study questions Ex: Chesapeake Bay study of runoff - System= watershed(land area that funnels water to a given river) -

Chesapeake Bay dead zones (Red and Orange color) - System of study= watershed and bay - Dead zones results from process called eutrophication - Starts with high levels of nitrogen(N) and phosphorous(P) - Mostly from agriculture

Dead zones - High N and P causes proliferation of phytoplankton - Microscopic algae, protists, cyanobacteria that drift near surface - Algal bloom - Eventually die and decomposers use up oxygen - Suffocation of oysters, grasses, fish, shrimp - Dead zone due to eutrophication

Environmental Systems’ Components or Levels of Organization

Chemistry and the Environment - Environmental systems are ultimately operating at the chemical level - Chemistry plays a key role in env’tl issues. Ex: How high N and P lead to low oxygen How air pollutants cause acid rain How synthetic chemistry thin the ozone layer How env’tl chemicals affect health Chemistry Basics - Matter: has mass and takes up space - Solid, liquid, gas - Conservation of matter: it cannot be created or destroyed, only transformed - Explains nutrient cycles (N and P) - Explains persistence of nuclear waste and toxic pollutants - Element: fundamental substance that cannot be simplified (C, H, O, N, P, S etc.) - Atom: smallest amount of an element - Molecule: 2+ atoms bonded together( ) - Compound: contains more than 1 element ( ) - Solution: mixed without bonding, usually liquid (air, blood, ocean water, etc.)

Organic compounds- contain C Hydrocarbons- contain only C and H

Energy - Intangible phenomenon that can change matter - Energy is conserved, but changes to lower quality - Organisms get energy - From sun= autotrophs or producers - Form other organisms= heterotrophs or consumers Ecosystems - All organisms and nonliving entities that occur and interact in a particular area - Can be small or large (puddle / lake) - Generally moderate size and somewhat self-contained - Energy flows through ecosystem in 1 direction - Matter cycles back within ecosystem

Ecosystem Productivity

Ecosystem Productivity - Productivity: rate at which autotrophs convert energy to biomass (leaves, stems, roots) - Which ecosystems have high productivity (consider what helps plants grow) Ecosystems and Landscape Ecology - Landscape ecology includes multiple ecosystems in larger geographic scales - Studies how landscape structure affects organisms Ex: bird migration, salmon swimming upriver

Ecosystem Services

Nutrient Cycles - Elements circulate through ecosystem Ex: water cycle - Human activities affect cycles - 2 examples here: N and P

Solutions for N and P Enrichment - Minimize nutrient runoff from agriculture 1. Reduce or change timing of fertilizer 2. Trap nutrients with vegetation buffers or artificial wetlands - Minimize atmospheric inputs - Improve sewage treatment - Use fewer phosphate detergents

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The Environment- living and non-living things Environment Science- how we affects environment and how environment affects

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us Natural Resources 1. Renewable- replenished over a short time -> sunlight wind

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2. Non-renewable- formed very slowly, limited or finite amount -> gas, oil, coal Natural Services- ecosystem services -> air and water purification, nutrient

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cycling pollination Human impact- interactions with the environment Impact results- IPAT model- impact, population, affluence, technology

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Ecological footprint- amount of land and water needed to sustain a person or population

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Environment- science- objective research Environmentalism- social movement dedicated to protecting the natural world

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Sustainability- how organisms can live well within our one plant Environment Ethics- relationship between humans and surroundings = Anthropocentric -> Biocentric -> Ecocentric

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Preservation- protects environment pristine, unaltered state. John Muir Conservation- uses natural resources with wise management. Gifford Pinchot

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Sustainable development- Environment protection + Economic development + Social justice

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Leapfrogging- countries develop Feedback loop 1. Negative feedback- restores balance to systems

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2. Positive feedback- moves system further to extreme Boundaries of systems- watershed Dead zones results from eutrophication- high level of nitrogen (N) and phosphorous (P)- mostly from agriculture 1. High N and P results to proliferation of phytoplankton 2. Algal boom 3. Die and decomposers use up oxygen 4. Suffocation of fish and shrimps 5. Dead zone due to eutrophication

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Chemistry Basics 1. Atom- smallest amount of an element 2. Element- fundamental substance that cannot be simplified 3. Molecule- 2+ atoms bonded together 4. Compound- mixed without bonding

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Energy- conserved, but changes to lower quality 1. From sun- autotrophs or producers 2. From other organisms- heterotrophs or consumers Ecosystems- all living and non-living 1. Energy flows through ecosystem in 1 direction 2. Matter cycles back within ecosystem Productivity- autotrophs convert energy to biomass (leaves, stems, roots). Have highly productive Solutions1. Minimize nutrient runoff from agriculture a. Reduce or change timing of fertilizer b. Trap nutrients with vegetation buffers or artificial wetlands 2. Minimize atmospheric inputs a. Improve sewage treatment

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b. Use fewer phosphate detergents Biodiversity- variety of life across all levels of biological organization Species- members share and can produce fertile offspring

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Populations- group of individuals of a particular species living in an area Evolution- diversity and unity of life

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Natural Selection 1. Inherited traits that enhance survival and reproduction are passed on

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2. Mechanism of evolution causing directional change 3. Charles Darwin and Alfred Russel Wallace Genetic Basics 1. Evolution occurs at the genetic level 2. Gene: region of DNA that codes for a protein

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3. Protein: molecules carry on all the work of life 4. Gene -> Protein -> Cell work Genetic Variation 1. Traits must be coded by DNA to be passed on Sources of Variation 1. Through mutation (change in DNA) 2. Through sexual reproduction (new combinations of genes ) Environmental Conditions 1. Interactions between genes and environment create perpetual process of change 2. Similar environments can lead to similar traits

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Evidence of Selection 1. Selective breeding 2. Insecticide resistance 3. Anatomical similarities

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Speciation 1. In the process by which new species are generated 2. In allopatric speciation, populations are physical separated

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3. Over generations, each population accumulated its own set of mutations Phylogenetic Trees

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1. Show relationships among species 2. Analyze patterns of similarity Ecology

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1. Study of interactions between organisms and their environment Population Size- number of individuals present at a given time

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Population density 1. Number of individuals per unit area 2. High rates find mates, but competition and disease Population dispersion- spatial arrangement of organisms Age structure- relative numbers of each age within population

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Growth rate- (birth rate + immigration) –( death rate+ emigration rate) Exponential rate 1. J shaped growth curve 2. New environment with abundant resources

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Limiting factors- constrain population growth Carrying Capacity (K)- maximum population size that environment can sustain Logistic Growth – initial fast growth is slowed and brought to K

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K- selected species – few offspring but with lots of care R – selected species- small offspring with no parental care

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Community- set of populations of different species living together in a particular area

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Competition 1. Competitive exclusion- one takes over resources 2. Resources partitioning- use slightly different resources or in different ways

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Feeding Hierarchy 1. Trophic level: rank in feeding hierarchy 2. Producers 3. Consumers 4. Decomposer and Detritivores

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Energy 1. Most energy lost as heat 2. About 10% of energy passes 3. Energy Pyramid Energy pyramid 1. Applies to numbers and biomass 2. Key implication- eating at lower trophic level Species Impact 1. Keystone species- have wide impact even though not abundant Community Disturbance 1. Primary succession- no life (volcano, glacier) 2. Secondary succession- some life remains (fire, hurricane, logging, farming) Biomes- major regional complex of similar communities 1. Recognized by characteristic plants 2. Determined by temperature and rain Phytoplankton (algae and cyanobacteria) -> trophic level is autotrophs and producers

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Certain cyanobacteria produces toxins -> microcytic. Makes humans and animals sick

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What causes algal bloom? Which leads to eutrophication 1. Optimal conditions for algal to grow

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2. Large inputs of phosphorus (P) and nitrogen (N) 3. Warmer waters form climate change Where do P and N come from?- Agricultural 1. N- atmosphere (N ), nitrogen is fixed by bacteria in soils 2. P- sedimentary rock, phosphorous is weathered from sedimentary rock

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Solutions 1. Top priority- reduce all forms of P and N going to lake Erie 2. Agricultural practice 3. Reduce sewer overflow problems 4. Research bacteria that might detoxify water

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5. Use chemical engineering to detoxify microcytic water Human can do 1. Use less fertilizer on lawns 2. Pushing for stricter Biodiversity- variety of life all levels of biological organization (members who

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share traits and can produce fertile offspring) How are species ...