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What is Ecology?What is

Ecology?

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What is Ecology??What is Ecology??

• The study of interactions between organisms and their environment.

• Tells how living organisms affect each other and the world they live in.

• The study of interactions between organisms and their environment.

• Tells how living organisms affect each other and the world they live in.

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Habitat & NicheHabitat & Niche• Habitat- where a plant or animal lives

• Niche-an organism’s way of life (what it does)

• Habitat- where a plant or animal lives

• Niche-an organism’s way of life (what it does)

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The Nonliving EnvironmentThe Nonliving Environment

• Abiotic factors- nonliving parts of an environment.

• Examples: air currents, temperature, moisture, light, and soil.

• Abiotic factors affect an organism’s life.

• Abiotic factors- nonliving parts of an environment.

• Examples: air currents, temperature, moisture, light, and soil.

• Abiotic factors affect an organism’s life.

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The Living EnvironmentThe Living Environment

• Biotic factors- all the organisms in an environment.

• All organisms depend on others directly or indirectly for food, shelter, reproduction, or protection.

• Biotic factors- all the organisms in an environment.

• All organisms depend on others directly or indirectly for food, shelter, reproduction, or protection.

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Abiotic or Biotic?Abiotic or Biotic?

Biotic

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Abiotic or Biotic?Abiotic or Biotic?

Abiotic

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Abiotic or Biotic?Abiotic or Biotic?

Abiotic

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Abiotic or Biotic?Abiotic or Biotic?

Biotic

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Levels of Organization

Levels of Organization

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What are the Simplest Levels?

What are the Simplest Levels?

• Atom• Molecule• Organelle• Cell• Tissue• Organ• System

• Atom• Molecule• Organelle• Cell• Tissue• Organ• System

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Levels of OrganizationLevels of Organization• Interactions of an organism

are placed into levels by complexity.

• Interactions of an organism are placed into levels by complexity.

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1st Level of Organization1st Level of Organization• Organism:

An individual is• made of cells, • uses energy,• reproduces,• responds, • grows and

develops

• Organism:An individual is

• made of cells, • uses energy,• reproduces,• responds, • grows and

develops

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2nd Level of Organization2nd Level of Organization• Population:

group of organisms, of the same species, living in the same place at the same time that interbreed

• Population:group of organisms, of the same species, living in the same place at the same time that interbreed

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PopulationsPopulations• Population Size

–Number of individuals in a population• Affects population’s ability to survive

• Ex. Smaller populations may be endangered by random events like natural disasters.

• Population Density–Number of individuals living

in a given area.

• Population Size–Number of individuals in a

population• Affects population’s ability to survive

• Ex. Smaller populations may be endangered by random events like natural disasters.

• Population Density–Number of individuals living

in a given area.

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Population GrowthPopulation Growth

• Populations grow when more individuals are born than die in a given period.

• Exponential Growth Curve- Rate of population growth is steady, so population size increases

exponentially.

• Populations grow when more individuals are born than die in a given period.

• Exponential Growth Curve- Rate of population growth is steady, so population size increases

exponentially.

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Exponential Growth Curve

Exponential Growth Curve

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Resources and Population Size

Resources and Population Size• Carrying Capacity

–maximum population (as of deer) an area can support without causing deterioration

• Density-dependent factors–resources that may be depleted by over population

• Carrying Capacity–maximum population (as of deer) an area can support without causing deterioration

• Density-dependent factors–resources that may be depleted by over population

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Logistic Model Logistic Model • Model that account for declining

resources effect on populations–When population is BELOW

carrying capacity, growth is RAPID.

–When population nears carrying capacity population growth slows down

–When population reaches carrying capacity, equilibrium is reached

• Model that account for declining resources effect on populations–When population is BELOW

carrying capacity, growth is RAPID.

–When population nears carrying capacity population growth slows down

–When population reaches carrying capacity, equilibrium is reached

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Logistic GrowthLogistic Growth

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Growth PatternsGrowth Patterns• R-strategists

–Populations grow rapidly

–Population size drops rapidly in poor conditions

–Short life spans–Many offspring–Little/no parental

care

• R-strategists–Populations grow

rapidly–Population size

drops rapidly in poor conditions

–Short life spans–Many offspring–Little/no parental

care

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Growth PatternsGrowth Patterns• K-strategists

–Population grows slowly

–Density near carrying capacity

–Long life span–Few offspring–Long term

parental care

• K-strategists–Population

grows slowly–Density near

carrying capacity

–Long life span–Few offspring–Long term

parental care

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Hardy-Weinberg Principle

Hardy-Weinberg Principle

• Frequencies of alleles in a population don’t change unless evolutionary pressures act on the population– These pressures are:

• Mutation• Gene Flow• Genetic Drift• Natural Selection

• Frequencies of alleles in a population don’t change unless evolutionary pressures act on the population– These pressures are:

• Mutation• Gene Flow• Genetic Drift• Natural Selection

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MutationMutation• Any change in DNA

–Does not change allele frequencies

–Not all mutations affect phenotype

–Some mutations change a protein & how it works

–Others don’t…–Mutation rates are slow but

may make evolution possible.

• Any change in DNA–Does not change allele

frequencies–Not all mutations affect

phenotype –Some mutations change a

protein & how it works–Others don’t…–Mutation rates are slow but

may make evolution possible.

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Gene FlowGene Flow

• The movement of alleles in or out of a population

• Caused by migration of individuals in or out of a population gene pool

• This adds or removes alleles

• The movement of alleles in or out of a population

• Caused by migration of individuals in or out of a population gene pool

• This adds or removes alleles

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Non-Random MatingNon-Random Mating• Individuals mate with others

nearby or of their own phenotype– Ex. Female peacocks prefer

male peacocks with best tail plumage • Alleles for very full tails

tend to increase in a population

• Inbreeding– Choosing to mate with

relatives– Increases the number of

homozygous individuals in a population

• Individuals mate with others nearby or of their own phenotype– Ex. Female peacocks prefer

male peacocks with best tail plumage • Alleles for very full tails

tend to increase in a population

• Inbreeding– Choosing to mate with

relatives– Increases the number of

homozygous individuals in a population

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Genetic DriftGenetic Drift

• Any change in gene frequency, especially due to disaster– Happens more often in small

populations– Ex. A fire breaks. Survivors carry

the polydactyl (multiple fingers and toes) allele.

– Soon, almost the entire population is polydactyl.

• Any change in gene frequency, especially due to disaster– Happens more often in small

populations– Ex. A fire breaks. Survivors carry

the polydactyl (multiple fingers and toes) allele.

– Soon, almost the entire population is polydactyl.

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Natural SelectionNatural Selection

• A change in the frequency of an allele due to its effects on survival and reproduction.

• Ex. Individuals that survive a malaria outbreak carry a gene for mutated hemoglobin- the sickle cell gene.

• The frequency of this allele will increase due to repopulation.

• A change in the frequency of an allele due to its effects on survival and reproduction.

• Ex. Individuals that survive a malaria outbreak carry a gene for mutated hemoglobin- the sickle cell gene.

• The frequency of this allele will increase due to repopulation.

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3rd Level of Organization3rd Level of OrganizationBiological Community:All the different populations living in the same place at the same time.

Biological Community:All the different populations living in the same place at the same time.

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SymbiosisSymbiosis

Interactions between closely associated, interdependant species. These are• PARASTISM• COMMENSALISM• MUTALISM

Interactions between closely associated, interdependant species. These are• PARASTISM• COMMENSALISM• MUTALISM

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ParasitismParasitism

One species benefits but the other is harmed (+/-)

• Ex. Leech sucking your blood!!!

One species benefits but the other is harmed (+/-)

• Ex. Leech sucking your blood!!!

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CommensalismCommensalism

One species benefits; the other is unaffected (+/o)

• Ex. Epiphytes grow on trees. They don’t harm or help the trees they live on.

One species benefits; the other is unaffected (+/o)

• Ex. Epiphytes grow on trees. They don’t harm or help the trees they live on.

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MutualismMutualismBoth species

benefit• Ex. Insects and

birds eat nectar from flowers. Pollen gets attached to their feet. At the next flower, they leave some, helping the reproduction of the plant.

Both species benefit

• Ex. Insects and birds eat nectar from flowers. Pollen gets attached to their feet. At the next flower, they leave some, helping the reproduction of the plant.

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4th Level of Organization4th Level of OrganizationEcosystem:

Populations of organisms that interact with each other and with the abiotic parts of that area. (terrestrial or aquatic)

Ecosystem: Populations of organisms that interact with each other and with the abiotic parts of that area. (terrestrial or aquatic)

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BiomesBiomes

• A major biological community that occurs over a large area of land.– Examples

• Tropical Rainforest• Savannas• Deserts• Taiga• Tundra• Temperate Grasslands• Temperate Deciduous Forest• Temperate Evergreen Forest• Freshwater Communities• Wetlands• Shallow Ocean Waters• Surface of the open Sea• Ocean Depths

• A major biological community that occurs over a large area of land.– Examples

• Tropical Rainforest• Savannas• Deserts• Taiga• Tundra• Temperate Grasslands• Temperate Deciduous Forest• Temperate Evergreen Forest• Freshwater Communities• Wetlands• Shallow Ocean Waters• Surface of the open Sea• Ocean Depths

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Cycles in EcosystemsCycles in Ecosystems

• Elements are recycled through the environment– Carbon– Water– Nitrogen

• Elements are recycled through the environment– Carbon– Water– Nitrogen

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Water CycleWater Cycle

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Carbon CycleCarbon Cycle

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Nitrogen CycleNitrogen Cycle

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5th Level of Organization5th Level of Organization

• Biosphere:The portion of Earth that supports life.

• Biosphere:The portion of Earth that supports life.

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The BiosphereThe Biosphere

• Life is in the air, land, fresh water and salt water.

• The BIOSPHERE is the part of Earth that supports living things.

• Life is in the air, land, fresh water and salt water.

• The BIOSPHERE is the part of Earth that supports living things.

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What level of organization?What level of organization?

Organism

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What level of Organization?What level of Organization?

Community

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What level of Organization?What level of Organization?

Population