EcologyEcologyEcologyEcology

Environmental ScienceEnvironmental ScienceEnvironmental ScienceEnvironmental Science

Levels of OrganizationLevels of Organization

Species A group of similar organisms that are able to

interbreed Population

All the members of a species living in one area at one time

Community All the populations of organisms living in one area

at one time Ecosystem

A community and its physical (non-living) environment

Species A group of similar organisms that are able to

interbreed Population

All the members of a species living in one area at one time

Community All the populations of organisms living in one area

at one time Ecosystem

A community and its physical (non-living) environment

Ecological InteractionsEcological InteractionsEcological InteractionsEcological Interactions

There are two types of factors There are two types of factors within an ecosystem.within an ecosystem.

Abiotic - Non-living factorsAbiotic - Non-living factors Biotic - Living factorsBiotic - Living factors Both can control what organisms Both can control what organisms

are found where. are found where.

There are two types of factors There are two types of factors within an ecosystem.within an ecosystem.

Abiotic - Non-living factorsAbiotic - Non-living factors Biotic - Living factorsBiotic - Living factors Both can control what organisms Both can control what organisms

are found where. are found where.

Ecological InteractionsEcological InteractionsEcological InteractionsEcological Interactions

The cycling of energy and The cycling of energy and compounds link all organisms compounds link all organisms within an ecosystem.within an ecosystem.

Affecting one organism in the web, Affecting one organism in the web, can affect organisms above, below, can affect organisms above, below, and beside it in the system.and beside it in the system.

DQ - Discuss an example where DQ - Discuss an example where changing one thing has effects changing one thing has effects on many others.on many others.

The cycling of energy and The cycling of energy and compounds link all organisms compounds link all organisms within an ecosystem.within an ecosystem.

Affecting one organism in the web, Affecting one organism in the web, can affect organisms above, below, can affect organisms above, below, and beside it in the system.and beside it in the system.

DQ - Discuss an example where DQ - Discuss an example where changing one thing has effects changing one thing has effects on many others.on many others.

Energy in EcosystemsEnergy in EcosystemsEnergy in EcosystemsEnergy in Ecosystems

First Law of Thermodynamics - Energy First Law of Thermodynamics - Energy cannot by created nor destroyed.cannot by created nor destroyed.

Second Law of Thermodynamics - Second Law of Thermodynamics - With each energy transfer in a system With each energy transfer in a system less energy is available.less energy is available.

What does this mean?What does this mean? DQ - Where does the energy go?DQ - Where does the energy go?

First Law of Thermodynamics - Energy First Law of Thermodynamics - Energy cannot by created nor destroyed.cannot by created nor destroyed.

Second Law of Thermodynamics - Second Law of Thermodynamics - With each energy transfer in a system With each energy transfer in a system less energy is available.less energy is available.

What does this mean?What does this mean? DQ - Where does the energy go?DQ - Where does the energy go?

Energy in EcosystemsEnergy in EcosystemsEnergy in EcosystemsEnergy in Ecosystems DQ - Where does energy come DQ - Where does energy come

from in eco systems?from in eco systems? Sun is major source for most but Sun is major source for most but

not all!not all! PhotosynthesisPhotosynthesis - Using light to - Using light to

make energy for the organismmake energy for the organism Chemosynthesis - using chemicals Chemosynthesis - using chemicals

to make energy for the organismto make energy for the organism DQ - How does energy get DQ - How does energy get

through the rest of the through the rest of the ecosystem?ecosystem?

DQ - Where does energy come DQ - Where does energy come from in eco systems?from in eco systems?

Sun is major source for most but Sun is major source for most but not all!not all!

PhotosynthesisPhotosynthesis - Using light to - Using light to make energy for the organismmake energy for the organism

Chemosynthesis - using chemicals Chemosynthesis - using chemicals to make energy for the organismto make energy for the organism

DQ - How does energy get DQ - How does energy get through the rest of the through the rest of the ecosystem?ecosystem?

Energy in EcosystemsEnergy in EcosystemsEnergy in EcosystemsEnergy in Ecosystems

Energy is transferred by organisms consuming Energy is transferred by organisms consuming other organismsother organisms The food chainThe food chain

1 min ACTIVTY - Come up with a food chain1 min ACTIVTY - Come up with a food chain There are several different levels to a food There are several different levels to a food

chainchain ProducersProducers Primary ConsumersPrimary Consumers Secondary ConsumersSecondary Consumers Tertiary ConsumersTertiary Consumers Quaternary ConsumersQuaternary Consumers DecomposersDecomposers

Energy is transferred by organisms consuming Energy is transferred by organisms consuming other organismsother organisms The food chainThe food chain

1 min ACTIVTY - Come up with a food chain1 min ACTIVTY - Come up with a food chain There are several different levels to a food There are several different levels to a food

chainchain ProducersProducers Primary ConsumersPrimary Consumers Secondary ConsumersSecondary Consumers Tertiary ConsumersTertiary Consumers Quaternary ConsumersQuaternary Consumers DecomposersDecomposers

Trophic LevelsTrophic LevelsTrophic LevelsTrophic Levels

Each of the levels is called a trophic Each of the levels is called a trophic levellevel

The amount of energy available The amount of energy available decreases as you move up each leveldecreases as you move up each level 2nd law of thermodynamics2nd law of thermodynamics

DQ - Why are there so many more DQ - Why are there so many more insects than tigers in the world?insects than tigers in the world?

Law of 10% - only 10% of energy is Law of 10% - only 10% of energy is passed to next level.passed to next level.

Each of the levels is called a trophic Each of the levels is called a trophic levellevel

The amount of energy available The amount of energy available decreases as you move up each leveldecreases as you move up each level 2nd law of thermodynamics2nd law of thermodynamics

DQ - Why are there so many more DQ - Why are there so many more insects than tigers in the world?insects than tigers in the world?

Law of 10% - only 10% of energy is Law of 10% - only 10% of energy is passed to next level.passed to next level.

Trophic LevelsTrophic LevelsTrophic LevelsTrophic Levels

Can be expressed in energy Can be expressed in energy pyramidspyramids

Page 64Page 64

Can be expressed in energy Can be expressed in energy pyramidspyramids

Page 64Page 64

Trophic LevelsTrophic LevelsTrophic LevelsTrophic Levels

Example problem - If the producer Example problem - If the producer started with 25,000 cal, how many started with 25,000 cal, how many would the primary consumer would the primary consumer obtain?obtain?

2,500 cal2,500 cal Tertiary consumer?Tertiary consumer? 25 cal25 cal DQ - What does this mean for DQ - What does this mean for

humans?humans?

Example problem - If the producer Example problem - If the producer started with 25,000 cal, how many started with 25,000 cal, how many would the primary consumer would the primary consumer obtain?obtain?

2,500 cal2,500 cal Tertiary consumer?Tertiary consumer? 25 cal25 cal DQ - What does this mean for DQ - What does this mean for

humans?humans?

Food WebFood WebFood WebFood Web

A food chain is useful in A food chain is useful in determining trophic levels, but not determining trophic levels, but not in showing interdependence.in showing interdependence.

For that we use For that we use food webfood webThis shows us several organisms This shows us several organisms

within an ecosystem.within an ecosystem. Shows that organisms are not Shows that organisms are not

always the same level in every always the same level in every chainchain

A food chain is useful in A food chain is useful in determining trophic levels, but not determining trophic levels, but not in showing interdependence.in showing interdependence.

For that we use For that we use food webfood webThis shows us several organisms This shows us several organisms

within an ecosystem.within an ecosystem. Shows that organisms are not Shows that organisms are not

always the same level in every always the same level in every chainchain

Food WebFood WebFood WebFood Web

AssignmentAssignmentAssignmentAssignment

Create an example food web with Create an example food web with at least 10 individual organisms. at least 10 individual organisms.

Then explain, if one organism were Then explain, if one organism were removed from the web how would removed from the web how would it effect the rest of the organisms.it effect the rest of the organisms.

Create an example food web with Create an example food web with at least 10 individual organisms. at least 10 individual organisms.

Then explain, if one organism were Then explain, if one organism were removed from the web how would removed from the web how would it effect the rest of the organisms.it effect the rest of the organisms.

Other factors to Other factors to interactionsinteractions

Other factors to Other factors to interactionsinteractions

DQ - What other types of interactions DQ - What other types of interactions are there within an ecosystem?are there within an ecosystem?

CompetitionCompetition Symbiotic RelationshipsSymbiotic Relationships

Commensalism, Mutualism, Parasitism Commensalism, Mutualism, Parasitism Predator-PreyPredator-Prey Keystone SpeciesKeystone Species Spatial DistributionSpatial Distribution MatingMating

DQ - What other types of interactions DQ - What other types of interactions are there within an ecosystem?are there within an ecosystem?

CompetitionCompetition Symbiotic RelationshipsSymbiotic Relationships

Commensalism, Mutualism, Parasitism Commensalism, Mutualism, Parasitism Predator-PreyPredator-Prey Keystone SpeciesKeystone Species Spatial DistributionSpatial Distribution MatingMating

ActivityActivityActivityActivity

Divide into groups of threeDivide into groups of three In your groups you will have one of In your groups you will have one of

the relationships listed on the the relationships listed on the previous slide to research and will previous slide to research and will present to the rest of the class.present to the rest of the class.

Divide into groups of threeDivide into groups of three In your groups you will have one of In your groups you will have one of

the relationships listed on the the relationships listed on the previous slide to research and will previous slide to research and will present to the rest of the class.present to the rest of the class.

PopulationsPopulationsPopulationsPopulations

Individuals of a species live in Individuals of a species live in populationspopulations

Population Population – consists of all the – consists of all the individuals of a species that live individuals of a species that live together in one place at one timetogether in one place at one time What is the reason for a definition like this?What is the reason for a definition like this?

So scientists can talk about all sorts of So scientists can talk about all sorts of populations with similar termspopulations with similar terms

Examples of populations?Examples of populations?

Individuals of a species live in Individuals of a species live in populationspopulations

Population Population – consists of all the – consists of all the individuals of a species that live individuals of a species that live together in one place at one timetogether in one place at one time What is the reason for a definition like this?What is the reason for a definition like this?

So scientists can talk about all sorts of So scientists can talk about all sorts of populations with similar termspopulations with similar terms

Examples of populations?Examples of populations?

PopulationsPopulationsPopulationsPopulations

Human population has tripled since 1930Human population has tripled since 1930 DQ - What could stop a population DQ - What could stop a population

from growing?from growing? Limited resources is #1 reasonLimited resources is #1 reason As well as other factorsAs well as other factors Thing to remember:Thing to remember: Populations are Populations are

constantly changingconstantly changing What do we mean by this?What do we mean by this?

Human population has tripled since 1930Human population has tripled since 1930 DQ - What could stop a population DQ - What could stop a population

from growing?from growing? Limited resources is #1 reasonLimited resources is #1 reason As well as other factorsAs well as other factors Thing to remember:Thing to remember: Populations are Populations are

constantly changingconstantly changing What do we mean by this?What do we mean by this?

PopulationsPopulationsPopulationsPopulations

Every population has features that Every population has features that help determine it’s future:help determine it’s future:

1. Population size1. Population size 2. Population density2. Population density 3. Dispersion3. Dispersion Each one can effect a populations Each one can effect a populations

in different ways.in different ways.

Every population has features that Every population has features that help determine it’s future:help determine it’s future:

1. Population size1. Population size 2. Population density2. Population density 3. Dispersion3. Dispersion Each one can effect a populations Each one can effect a populations

in different ways.in different ways.

PopulationsPopulationsPopulationsPopulations Population sizePopulation size – the number of individuals in a – the number of individuals in a

populationpopulation DQ - How could this determine the future?DQ - How could this determine the future? Small populations are affected by disturbances Small populations are affected by disturbances

more than large populationsmore than large populations Inbreeding is a big problem with a small Inbreeding is a big problem with a small

populationpopulation DQ - Why would this be?DQ - Why would this be? Inbreeding causes the population to be Inbreeding causes the population to be

genetically identical, meaning one disease can genetically identical, meaning one disease can wipe out entire populationwipe out entire population

Population sizePopulation size – the number of individuals in a – the number of individuals in a populationpopulation

DQ - How could this determine the future?DQ - How could this determine the future? Small populations are affected by disturbances Small populations are affected by disturbances

more than large populationsmore than large populations Inbreeding is a big problem with a small Inbreeding is a big problem with a small

populationpopulation DQ - Why would this be?DQ - Why would this be? Inbreeding causes the population to be Inbreeding causes the population to be

genetically identical, meaning one disease can genetically identical, meaning one disease can wipe out entire populationwipe out entire population

Estimating PopulationEstimating PopulationEstimating PopulationEstimating Population Within ecosystems, scientists have to have an Within ecosystems, scientists have to have an

idea of the population of an organism.idea of the population of an organism. This helps them understand how organisms will This helps them understand how organisms will

interactinteract DQ - How do they do that?DQ - How do they do that? Most popular is the capture-recapture methodMost popular is the capture-recapture method Uses a formula:Uses a formula:

Marked organism recapturedMarked organism recaptured = = total markedtotal marked

Total organisms captured (rnd 2) pop. sizeTotal organisms captured (rnd 2) pop. size

Within ecosystems, scientists have to have an Within ecosystems, scientists have to have an idea of the population of an organism.idea of the population of an organism.

This helps them understand how organisms will This helps them understand how organisms will interactinteract

DQ - How do they do that?DQ - How do they do that? Most popular is the capture-recapture methodMost popular is the capture-recapture method Uses a formula:Uses a formula:

Marked organism recapturedMarked organism recaptured = = total markedtotal marked

Total organisms captured (rnd 2) pop. sizeTotal organisms captured (rnd 2) pop. size

ActivityActivityActivityActivity

We are going to demonstrate this We are going to demonstrate this method and practice using the method and practice using the formulaformula

Toothpick estimation labToothpick estimation lab Individual labIndividual lab

We are going to demonstrate this We are going to demonstrate this method and practice using the method and practice using the formulaformula

Toothpick estimation labToothpick estimation lab Individual labIndividual lab

PopulationsPopulationsPopulationsPopulations

Population DensityPopulation Density – the number of – the number of individuals that live in a given areaindividuals that live in a given area

DQ - How is this different than DQ - How is this different than population?population?

DQ - How would this effect a DQ - How would this effect a population?population?

If individuals are very spread out, they may If individuals are very spread out, they may rarely meet, meaning reproduction is sparserarely meet, meaning reproduction is sparse

DQ - What might happen if too close DQ - What might happen if too close together?together?

Population DensityPopulation Density – the number of – the number of individuals that live in a given areaindividuals that live in a given area

DQ - How is this different than DQ - How is this different than population?population?

DQ - How would this effect a DQ - How would this effect a population?population?

If individuals are very spread out, they may If individuals are very spread out, they may rarely meet, meaning reproduction is sparserarely meet, meaning reproduction is sparse

DQ - What might happen if too close DQ - What might happen if too close together?together?

PopulationsPopulationsPopulationsPopulations

DispersionDispersion – the way the individuals of – the way the individuals of the population are arranged in spacethe population are arranged in space

There are three main patterns of There are three main patterns of dispersion:dispersion: ClumpedClumped RandomRandom UniformUniform

DQ - How would this effect the DQ - How would this effect the population?population?

DispersionDispersion – the way the individuals of – the way the individuals of the population are arranged in spacethe population are arranged in space

There are three main patterns of There are three main patterns of dispersion:dispersion: ClumpedClumped RandomRandom UniformUniform

DQ - How would this effect the DQ - How would this effect the population?population?

Scientist use models to predict how Scientist use models to predict how populations will growpopulations will grow

Three types of growth rateThree types of growth rate 1. Stage I model1. Stage I model

Rate of growth = birthrate – death rateRate of growth = birthrate – death rate 2. Exponential growth curve2. Exponential growth curve

Also called the stage II modelAlso called the stage II modelComplicated equationComplicated equationSet interval of reproduction Set interval of reproduction

(example – bacteria)(example – bacteria)

Scientist use models to predict how Scientist use models to predict how populations will growpopulations will grow

Three types of growth rateThree types of growth rate 1. Stage I model1. Stage I model

Rate of growth = birthrate – death rateRate of growth = birthrate – death rate 2. Exponential growth curve2. Exponential growth curve

Also called the stage II modelAlso called the stage II modelComplicated equationComplicated equationSet interval of reproduction Set interval of reproduction

(example – bacteria)(example – bacteria)

PopulationsPopulationsPopulationsPopulations

The third type of Growth Rate:The third type of Growth Rate: 3. Logistic Growth3. Logistic Growth

Also called Stage III modelAlso called Stage III modelAnother complicated equationAnother complicated equationTakes into account the limited Takes into account the limited

amount of resources amount of resources Best one for natureBest one for natureCan cause frequency of changes within Can cause frequency of changes within

populationpopulation Carrying CapacityCarrying Capacity – population size – population size

that the environment can sustain.that the environment can sustain.

The third type of Growth Rate:The third type of Growth Rate: 3. Logistic Growth3. Logistic Growth

Also called Stage III modelAlso called Stage III modelAnother complicated equationAnother complicated equationTakes into account the limited Takes into account the limited

amount of resources amount of resources Best one for natureBest one for natureCan cause frequency of changes within Can cause frequency of changes within

populationpopulation Carrying CapacityCarrying Capacity – population size – population size

that the environment can sustain.that the environment can sustain.

PopulationsPopulationsPopulationsPopulations

PopulationsPopulationsPopulationsPopulations

Real populations exhibit a range of Real populations exhibit a range of growth patternsgrowth patterns

DQ - Why might this be?DQ - Why might this be? Many times organisms overshoot Many times organisms overshoot

then die offthen die off DQ - What would this look like DQ - What would this look like

on a graph?on a graph?

Real populations exhibit a range of Real populations exhibit a range of growth patternsgrowth patterns

DQ - Why might this be?DQ - Why might this be? Many times organisms overshoot Many times organisms overshoot

then die offthen die off DQ - What would this look like DQ - What would this look like

on a graph?on a graph?

PopulationsPopulationsPopulationsPopulations Population pyramids:Population pyramids: Population pyramids:Population pyramids:

Population ChangesPopulation ChangesPopulation ChangesPopulation Changes Populations have factors that help Populations have factors that help

determine life expectancy and determine life expectancy and survivorship.survivorship.

Life expectancyLife expectancy - the probable - the probable number of years of survival for an number of years of survival for an individualindividual

SurvivorshipSurvivorship - % of a population - % of a population that survives to a certain age.that survives to a certain age.

Environmental resistanceEnvironmental resistance - - environmental factors that cause environmental factors that cause the carrying capacitythe carrying capacity

Populations have factors that help Populations have factors that help determine life expectancy and determine life expectancy and survivorship.survivorship.

Life expectancyLife expectancy - the probable - the probable number of years of survival for an number of years of survival for an individualindividual

SurvivorshipSurvivorship - % of a population - % of a population that survives to a certain age.that survives to a certain age.

Environmental resistanceEnvironmental resistance - - environmental factors that cause environmental factors that cause the carrying capacitythe carrying capacity

DQ - What are some of DQ - What are some of these factors?these factors?

DQ - What are some of DQ - What are some of these factors?these factors?

Factors that influence populations:Factors that influence populations: PredationPredation Amount of resourcesAmount of resources Human interactionHuman interaction Gene flowGene flow DiseaseDisease Natural disastersNatural disasters OthersOthers

Factors that influence populations:Factors that influence populations: PredationPredation Amount of resourcesAmount of resources Human interactionHuman interaction Gene flowGene flow DiseaseDisease Natural disastersNatural disasters OthersOthers

Survivorship curvesSurvivorship curvesSurvivorship curvesSurvivorship curves 4 main types of survivorship4 main types of survivorship Each curve represents different types Each curve represents different types

death rates.death rates. Each curve has several animals that Each curve has several animals that

can be used for examplescan be used for examples No fancy names just No fancy names just Type 1,2,3, Type 1,2,3, andand

44 Easier to identify with the animals Easier to identify with the animals

that follow the curve.that follow the curve. Pg. 123 in bookPg. 123 in book

4 main types of survivorship4 main types of survivorship Each curve represents different types Each curve represents different types

death rates.death rates. Each curve has several animals that Each curve has several animals that

can be used for examplescan be used for examples No fancy names just No fancy names just Type 1,2,3, Type 1,2,3, andand

44 Easier to identify with the animals Easier to identify with the animals

that follow the curve.that follow the curve. Pg. 123 in bookPg. 123 in book

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Survivorship CurvesSurvivorship CurvesSurvivorship CurvesSurvivorship Curves Type 1 -Type 1 - What is going on? What is going on? Most organisms survive to old age, then Most organisms survive to old age, then

die off quicklydie off quickly Example organisms?Example organisms?

Humans, most top consumers in an Humans, most top consumers in an ecosystemecosystem

Type 2Type 2 - What is going on? - What is going on? Organisms die off at a pretty steady rateOrganisms die off at a pretty steady rate

Death not as related to ageDeath not as related to age Examples?Examples?

Many birds, including seagulls and hawks Many birds, including seagulls and hawks

Type 1 -Type 1 - What is going on? What is going on? Most organisms survive to old age, then Most organisms survive to old age, then

die off quicklydie off quickly Example organisms?Example organisms?

Humans, most top consumers in an Humans, most top consumers in an ecosystemecosystem

Type 2Type 2 - What is going on? - What is going on? Organisms die off at a pretty steady rateOrganisms die off at a pretty steady rate

Death not as related to ageDeath not as related to age Examples?Examples?

Many birds, including seagulls and hawks Many birds, including seagulls and hawks

Survivorship curvesSurvivorship curvesSurvivorship curvesSurvivorship curves Type 3 - What is going on?Type 3 - What is going on? High young mortality rate but if they survive, High young mortality rate but if they survive,

live very long liveslive very long lives Examples?Examples?

Fish, trees, most animals at the bottom of the Fish, trees, most animals at the bottom of the food chainfood chain

Type 4 - What is going on?Type 4 - What is going on? High mortality before maturity and after High mortality before maturity and after

reproductive agereproductive age Examples?Examples?

Humans (developing), deer, rabbitsHumans (developing), deer, rabbits

Type 3 - What is going on?Type 3 - What is going on? High young mortality rate but if they survive, High young mortality rate but if they survive,

live very long liveslive very long lives Examples?Examples?

Fish, trees, most animals at the bottom of the Fish, trees, most animals at the bottom of the food chainfood chain

Type 4 - What is going on?Type 4 - What is going on? High mortality before maturity and after High mortality before maturity and after

reproductive agereproductive age Examples?Examples?

Humans (developing), deer, rabbitsHumans (developing), deer, rabbits

Population ChangesPopulation ChangesPopulation ChangesPopulation Changes

Populations have trait frequenciesPopulations have trait frequencies These frequencies will stay the These frequencies will stay the

same as long as outside factors do same as long as outside factors do not influence the populationnot influence the population

What is wrong with this?What is wrong with this? There are always outside factors There are always outside factors

that influence populations!!!!that influence populations!!!! What are some of these factors?What are some of these factors?

Populations have trait frequenciesPopulations have trait frequencies These frequencies will stay the These frequencies will stay the

same as long as outside factors do same as long as outside factors do not influence the populationnot influence the population

What is wrong with this?What is wrong with this? There are always outside factors There are always outside factors

that influence populations!!!!that influence populations!!!! What are some of these factors?What are some of these factors?

Population ChangesPopulation ChangesPopulation ChangesPopulation Changes Another factor that can effect how a Another factor that can effect how a

population changes:population changes: Natural selectionNatural selection The organism that is best fit for its The organism that is best fit for its

environment will eventually environment will eventually dominate the population frequenciesdominate the population frequenciesSurvival of the fittestSurvival of the fittestOccurs when there is variation in a Occurs when there is variation in a

populationpopulation

Another factor that can effect how a Another factor that can effect how a population changes:population changes:

Natural selectionNatural selection The organism that is best fit for its The organism that is best fit for its

environment will eventually environment will eventually dominate the population frequenciesdominate the population frequenciesSurvival of the fittestSurvival of the fittestOccurs when there is variation in a Occurs when there is variation in a

populationpopulation

Population ChangesPopulation ChangesPopulation ChangesPopulation Changes Types of Selection:Types of Selection: Directional selectionDirectional selection – the form of – the form of

selection that causes the frequency selection that causes the frequency of a particular trait to move in one of a particular trait to move in one directiondirection

Causes the trait to become Causes the trait to become more or less common more or less commonExamples?Examples?

Types of Selection:Types of Selection: Directional selectionDirectional selection – the form of – the form of

selection that causes the frequency selection that causes the frequency of a particular trait to move in one of a particular trait to move in one directiondirection

Causes the trait to become Causes the trait to become more or less common more or less commonExamples?Examples?

Population ChangesPopulation ChangesPopulation ChangesPopulation Changes

Types of Selection:Types of Selection: Stabilizing selection – Stabilizing selection –

distribution of traits becomes distribution of traits becomes narrowernarrower

Eliminates the extremes Eliminates the extremes of the trait of the traitExamples?Examples?

More common in natureMore common in nature

Types of Selection:Types of Selection: Stabilizing selection – Stabilizing selection –

distribution of traits becomes distribution of traits becomes narrowernarrower

Eliminates the extremes Eliminates the extremes of the trait of the traitExamples?Examples?

More common in natureMore common in nature

AssignmentAssignmentAssignmentAssignment

Pg 129 PQ - 2,6,9 CT - 2, 4Pg 129 PQ - 2,6,9 CT - 2, 4 Bring a tube of M&M minisBring a tube of M&M minis Quiz tomorrowQuiz tomorrow

Pg 129 PQ - 2,6,9 CT - 2, 4Pg 129 PQ - 2,6,9 CT - 2, 4 Bring a tube of M&M minisBring a tube of M&M minis Quiz tomorrowQuiz tomorrow

ActivityActivityActivityActivity

Hunting M&Ms on FabricHunting M&Ms on Fabric Hunting M&Ms on FabricHunting M&Ms on Fabric

Ecosystem HealthEcosystem HealthEcosystem HealthEcosystem Health

Several ways to judge how healthy an Several ways to judge how healthy an ecosystem is.ecosystem is.

DQ - What do you think those DQ - What do you think those are?are?

ProductivityProductivity BiodiversityBiodiversity Cycling of materialsCycling of materials DQ - How do each of these affect DQ - How do each of these affect

how healthy the ecosystem is?how healthy the ecosystem is?

Several ways to judge how healthy an Several ways to judge how healthy an ecosystem is.ecosystem is.

DQ - What do you think those DQ - What do you think those are?are?

ProductivityProductivity BiodiversityBiodiversity Cycling of materialsCycling of materials DQ - How do each of these affect DQ - How do each of these affect

how healthy the ecosystem is?how healthy the ecosystem is?

BiodiversityBiodiversityBiodiversityBiodiversity

What is it?What is it? the number of different species living the number of different species living

within an eco-systemwithin an eco-system High Biodiversity = ??High Biodiversity = ?? Better healthBetter health Plays a HUGE role in determining Plays a HUGE role in determining

the complexity and resiliency of a the complexity and resiliency of a systemsystem

What are these?What are these?

What is it?What is it? the number of different species living the number of different species living

within an eco-systemwithin an eco-system High Biodiversity = ??High Biodiversity = ?? Better healthBetter health Plays a HUGE role in determining Plays a HUGE role in determining

the complexity and resiliency of a the complexity and resiliency of a systemsystem

What are these?What are these?

BiodiversityBiodiversityBiodiversityBiodiversity

Complexity - # of species at each Complexity - # of species at each trophic leveltrophic level

High complexity = Better healthHigh complexity = Better health DQ - Why?DQ - Why? Resiliency - Resistance to Resiliency - Resistance to

DisturbancesDisturbances There are always disturbances so There are always disturbances so

systems need a high resiliency.systems need a high resiliency.

Complexity - # of species at each Complexity - # of species at each trophic leveltrophic level

High complexity = Better healthHigh complexity = Better health DQ - Why?DQ - Why? Resiliency - Resistance to Resiliency - Resistance to

DisturbancesDisturbances There are always disturbances so There are always disturbances so

systems need a high resiliency.systems need a high resiliency.

ProductivityProductivityProductivityProductivity

What is it?What is it? The rate of biomass productionThe rate of biomass production Why would this be a big deal?Why would this be a big deal? DQ - Relates directly to the amount of DQ - Relates directly to the amount of

energy available to the system.energy available to the system. More productivity means more of the suns energy More productivity means more of the suns energy

is being converted.is being converted. DQ - Examples of consistently DQ - Examples of consistently

productive ecosystems?productive ecosystems? Forests, coral reefs, estuaries, agricultural Forests, coral reefs, estuaries, agricultural

land.land.

What is it?What is it? The rate of biomass productionThe rate of biomass production Why would this be a big deal?Why would this be a big deal? DQ - Relates directly to the amount of DQ - Relates directly to the amount of

energy available to the system.energy available to the system. More productivity means more of the suns energy More productivity means more of the suns energy

is being converted.is being converted. DQ - Examples of consistently DQ - Examples of consistently

productive ecosystems?productive ecosystems? Forests, coral reefs, estuaries, agricultural Forests, coral reefs, estuaries, agricultural

land.land.

Cycling of materialsCycling of materialsCycling of materialsCycling of materials

There is a cycle of materials within There is a cycle of materials within an ecosysteman ecosystem

The four most important ones:The four most important ones:carbon, nitrogen, phosphorus and carbon, nitrogen, phosphorus and waterwater

If something throws off the cycle, If something throws off the cycle, the eco-system loses materials, the eco-system loses materials, and becomes weakerand becomes weaker

There is a cycle of materials within There is a cycle of materials within an ecosysteman ecosystem

The four most important ones:The four most important ones:carbon, nitrogen, phosphorus and carbon, nitrogen, phosphorus and waterwater

If something throws off the cycle, If something throws off the cycle, the eco-system loses materials, the eco-system loses materials, and becomes weakerand becomes weaker

Eco-systems

Water cycle:

Eco-systems

Carbon Cycle:

Eco-systems

Nitrogen cycle

Changing EcosystemsChanging EcosystemsChanging EcosystemsChanging Ecosystems

Sometimes the disturbances can Sometimes the disturbances can destroy an ecosystem or part of it. destroy an ecosystem or part of it.

Sometimes this is beneficial to Sometimes this is beneficial to many speciesmany speciesForest Fires, Volcanoes, floodsForest Fires, Volcanoes, floods

How can it be beneficial?How can it be beneficial? Brings nutrients to the system, and Brings nutrients to the system, and

breaks up the dominant speciesbreaks up the dominant species Cause the community to changeCause the community to change

Sometimes the disturbances can Sometimes the disturbances can destroy an ecosystem or part of it. destroy an ecosystem or part of it.

Sometimes this is beneficial to Sometimes this is beneficial to many speciesmany speciesForest Fires, Volcanoes, floodsForest Fires, Volcanoes, floods

How can it be beneficial?How can it be beneficial? Brings nutrients to the system, and Brings nutrients to the system, and

breaks up the dominant speciesbreaks up the dominant species Cause the community to changeCause the community to change

Communities changingCommunities changingCommunities changingCommunities changing

As communities changes new types of As communities changes new types of species can take overspecies can take over

This is called successionThis is called succession Two Types:Two Types:

Primary succession - land that is bare of Primary succession - land that is bare of soil. (nothing lived there before)soil. (nothing lived there before)

Secondary succession - existing Secondary succession - existing community is disturbed and a new one community is disturbed and a new one develops.develops.

As communities changes new types of As communities changes new types of species can take overspecies can take over

This is called successionThis is called succession Two Types:Two Types:

Primary succession - land that is bare of Primary succession - land that is bare of soil. (nothing lived there before)soil. (nothing lived there before)

Secondary succession - existing Secondary succession - existing community is disturbed and a new one community is disturbed and a new one develops.develops.

SuccessionSuccessionSuccessionSuccession

As time goes on, the system As time goes on, the system becomes more complicated.becomes more complicated.

Pioneer species - first colonistsPioneer species - first colonistsCan survive on few resourcesCan survive on few resourcesLichens, mosses, microbesLichens, mosses, microbes

They create organic material and They create organic material and nutrients for later speciesnutrients for later species

Ends with Climax Community that Ends with Climax Community that lasts until the next large disturbancelasts until the next large disturbance

As time goes on, the system As time goes on, the system becomes more complicated.becomes more complicated.

Pioneer species - first colonistsPioneer species - first colonistsCan survive on few resourcesCan survive on few resourcesLichens, mosses, microbesLichens, mosses, microbes

They create organic material and They create organic material and nutrients for later speciesnutrients for later species

Ends with Climax Community that Ends with Climax Community that lasts until the next large disturbancelasts until the next large disturbance