Populations and Populations and CommunitiesCommunities
Living Things and the Living Things and the EnvironmentEnvironment
A little vocab…A little vocab… EcologyEcology - the study of - the study of
how organisms interact how organisms interact with their environmentwith their environment
OrganismOrganism - a living - a living thingthing
HabitatHabitat - the specific - the specific environment that environment that provides the things an provides the things an organism needs to live, organism needs to live, grow, and reproducegrow, and reproduce
Living or Nonliving?Living or Nonliving?
Biotic FactorBiotic Factor - living parts of a - living parts of a habitathabitat
– ExamplesExamples - flowers, worm, frog - flowers, worm, frog
Abiotic FactorAbiotic Factor - nonliving part of - nonliving part of a habitata habitat
– ExamplesExamples - water, sunlight, oxygen - water, sunlight, oxygen
The Line-UpThe Line-Up SpeciesSpecies - group of organisms - group of organisms
that mate and reproducethat mate and reproduce
PopulationPopulation - all members of - all members of oneone species in a particular species in a particular areaarea
CommunityCommunity - all - all differentdifferent populations that live in an populations that live in an areaarea
EcosystemEcosystem - a community - a community including its surrounding including its surrounding environment (abiotic factors)environment (abiotic factors)
Populations and Populations and CommunitiesCommunities
Studying PopulationsStudying Populations
Types of ObservationsTypes of Observations
Direct ObservationDirect Observation - counting all - counting all individuals by onesindividuals by ones
Indirect ObservationIndirect Observation - counting the - counting the “signs” of an individual“signs” of an individual
Methods of StudyMethods of Study SamplingSampling - taking an - taking an
estimate of a type of estimate of a type of organism in an areaorganism in an area
Mark-and-Mark-and-Recapture StudiesRecapture Studies - catch an organism, - catch an organism, mark it, then releasemark it, then release
Population FluctuationPopulation Fluctuation Birth RateBirth Rate - # of births in a population - # of births in a population
during a specific timeduring a specific time
Death RateDeath Rate - # of deaths in a population - # of deaths in a population during a specific timeduring a specific time
If birth rate is > than death rate, then If birth rate is > than death rate, then population is ____________population is ____________
If birth rate is < than death rate, then If birth rate is < than death rate, then population is ____________population is ____________
Population FluctuationPopulation Fluctuation
ImmigrationImmigration - organisms moving - organisms moving intointo a a populationpopulation
EmigrationEmigration - organisms moving - organisms moving outout of a of a populationpopulation
Population Growth Equation:Population Growth Equation:
(B - D) + (I - E) = N(B - D) + (I - E) = N
*If N is a positive #, the population is increasing*If N is a positive #, the population is increasing
Population FluctuationPopulation Fluctuation
Population DensityPopulation Density - # of - # of individuals in a specific areaindividuals in a specific area
Population Density Equation:Population Density Equation:
# individuals# individuals
Unit areaUnit area
Population FactorsPopulation Factors Limiting FactorLimiting Factor - an environmental factor - an environmental factor
that causes a population to decreasethat causes a population to decrease– Examples:Examples: food and water, space and weather food and water, space and weather
Carrying Capacity (K)Carrying Capacity (K) - the largest - the largest population that an area can carrypopulation that an area can carry
Populations and Populations and CommunitiesCommunities
Interactions Among Living Interactions Among Living ThingsThings
The TheoryThe Theory Natural SelectionNatural Selection – –
individuals who have individuals who have the best characteristics the best characteristics are more likely to are more likely to survive and produce survive and produce offspringoffspring
– Charles DarwinCharles Darwin – (1809 – (1809 – 1882) father of – 1882) father of evolutionary biologyevolutionary biology
A Place in the WorldA Place in the World AdaptationsAdaptations – a physical – a physical
characteristic that helps an organism characteristic that helps an organism live in an area live in an area – Example:Example: cacti in the desert cacti in the desert
NicheNiche – the role of an organism in its – the role of an organism in its habitat, or how it makes its livinghabitat, or how it makes its living– type of food I eattype of food I eat– Who else eats youWho else eats you– Whether you need to surviveWhether you need to survive
The FightThe Fight
CompetitionCompetition – the struggle (fight) – the struggle (fight) between two organism to get the between two organism to get the same thingsame thing
Let’s Eat!Let’s Eat! PredationPredation – when one organism kills – when one organism kills
another for foodanother for food
– PredatorPredator – dominant organism – dominant organismPredator AdaptationsPredator Adaptations – help them catch – help them catch
and kill their preyand kill their prey
– PreyPrey – inferior organism – inferior organismPrey Defense StrategiesPrey Defense Strategies – certain – certain
adaptations to prevent being killed by adaptations to prevent being killed by predatorspredators
– Skunk, poison ivy, porcupinesSkunk, poison ivy, porcupines
RelationshipsRelationships MutualismMutualism – both species benefit – both species benefit
– ExampleExample – hippo and bird – hippo and bird
CommensalismCommensalism – one species benefits – one species benefits and the other is neither helped nor and the other is neither helped nor harmedharmed– ExampleExample – clown fish and sea anemone – clown fish and sea anemone
ParasitismParasitism – one species is benefited and – one species is benefited and the other is harmed. Doesn’t kill because the other is harmed. Doesn’t kill because it needs the host to liveit needs the host to live– ExampleExample – head lice, ringworm, tape worm, – head lice, ringworm, tape worm,
ticksticks
RelationshipRelationship Species OneSpecies One Species TwoSpecies Two
MutualismMutualism ++ ++
CommensalismCommensalism ++ OO
ParasitismParasitism ++ --
Populations and Populations and CommunitiesCommunities
Changes in CommunitiesChanges in Communities
Primary SuccessionPrimary Succession Where no soil or organisms existWhere no soil or organisms exist
– Example: rocks after volcano erupts or Example: rocks after volcano erupts or glaciersglaciers
Pioneer SpeciesPioneer Species – the very first – the very first organisms that inhabit an areaorganisms that inhabit an area– How do they get there?How do they get there?
wind, water, other organisms carry themwind, water, other organisms carry them
– What are they?What are they?Lichens and mossLichens and moss
Secondary SuccessionSecondary Succession
A series of changes in an area where A series of changes in an area where the ecosystem has been disturbed, the ecosystem has been disturbed, but the soil and organisms still existbut the soil and organisms still exist– Example – tornadoes, hurricanes, fires, Example – tornadoes, hurricanes, fires,
logging, and farminglogging, and farming– Faster rate of successionFaster rate of succession
Succession DiagramSuccession Diagram
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