Transcript AP Biology Ecology Unit

AP Biology
Ecology Unit
Chapters 50 - 54…55
Ch. 50 Review
 Unit
has separate ppt.
 You should know/understand:
– Scope of ecology is huge, it
encompasses chemistry, biology,
geology and evolution ( adaptations,
natural selection, mutations/rates, etc)
– Living organisms are interconnected and
connected to their environments
– The environment has living and
nonliving components
50 continued
 Climate
– The longer term, prevailing weather
patterns.
– Earth has perfect conditions for life ( as
we know it) to exist
– Biomes, and their vegetation are
defined by the climate
– Oceans (position, volume, temperature)
are responsible for air and water
currents  global weather.
Biomes
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Terrestrial Ecosystems
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Tropical rain forests
Temperate rain forests
Savanna
Desert
Chaparral
Temp. grassland
Temp.deciduous forests
Coniferous forests
Tundra
Taiga
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Aquatic Ecosystems
– Marine (salt)
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Intertidal
Coral reef
Open ocean
Benthos
– Freshwater
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Oligotrophic lake
Eutrophic lake
Mesotrophic lake
Wetland
River/ stream
estuary
50 – last review
 Principle
of Allocation
– Finite amount of energy (calories) to
accomplish all life processes
– These resources must be divided up to
meet needs of the individual species
 Do
you invest a lot in growth or in nest
building? Are your flowers showy or do you
have many seeds?
 Regulators vs. conformers
Ch. 51 – Behavioral Biology
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Bird species find mates and defend territories
with specific songs – how do they “know” how to
do this…. Are behaviors genetic and how have
they evolved?
Much of behavior is “act-reaction”, some
behaviors also appear to be learned.
– Some components are physiological and therefore
obviously genetic
– Other behaviors lend themselves to questions such as
‘why did ancestral species start doing this’ – ‘ how do
they know?’
Human Context
Recent discoveries of “genes for”
depression, alcoholism and violence
 Chemistry within cells and chemistry of
environment while egg is developing and
interactions of chemistry involved in
nervous system…. All interrelated
 “Research into heritability (of behavior) is
the best demonstration I know of the
importance of environment. They (genes
and nongenetic environmental factors)
build on each other”
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– Robert Plomin, Pennsylvania State University
Ethology – study of
behaviors
 Innate – born with
 Developmentally
fixed – all
individuals have
regardless of their
environment
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– All new birds open
mouth and cheep
– Range of innate
behaviors
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See bird pictures
Adaptive nature of behavior
Fixed action
pattern – behavior
that is
unchangeable
 Triggered by sign
stimulus
 Examples
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– Pine cones = nest
– Red = aggression
Evolution of behaviors

Having a larger
repertoire –
increases your
fitness
– See
– Hear
– forage
Learning

Modification of behavior based on prior
experiences
– Language; ability to learn a language is innate
(genetic)
– Which language (or song bird dialect0 you
learn depends on environment and exposure
Innate behaviors can also be expressed
because of maturation
 Habituation – loss of response if stimulus
has no information
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Imprinting
 Learning
is limited to a specific time
period in the animals life and is
generally irreversible
 Critical period
– Imprinting of geese
– Song bird repertoire
Learning associated with stimuli
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Associative learning
– Learn to associate one behavior with another behavior
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Classical conditioning
– Pavlov’s dogs = hear bell get food, learn to salivate at
sound of bell
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Operant conditioning
– Trial and error/ reward and punishment
– Skinner’s rat box
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Play
– Animals often play, with the goal of learning to associate
a behavior with a result.
– Cats playing “tackle” are learning to hunt
– Can potentially be dangerous results to “horsing around”
– May be more adaptive in terms of building muscle
strength and coordination
Cognition
 Ability
of the nervous system to
perceive, process and store
information gathered by the senses.
– Problem solving of birds and chimps
– Sophisticated behaviors
– Dogs catching Frisbees
– Kinesis (rate of behavior) Taxis
(movement to or from stimulus)
– Migration; regular/ predictable
movement over long distances
Social Behavior
William Hamilton and E.O. Wilson
 Agonistic; threatening and submissive
 Ritual; symbolic activity
 Dominance hierarchy; pecking order
 Territoriality; establish and defend
 Courtship; displays and parental
investment
 Mating systems; promiscuous,
monogamous, polygamous
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Social Behavior
Altruism
 Animals
usually act in ways that
minimize competition and are
therefore “selfish”
 Altruistic behaviors actually reduce
your individual fitness to benefit the
group.
– Sterile worker bees
– Sentry prairie dogs
“help your kin”
Inclusive fitness = total effect an
individual has on proliferating its genes
and aiding close relatives
 Coefficient of relatedness = altruism
seems proportional to percentage of genes
that are similar between an individual and
its relatives…. Helping gene pool if aid a
cousin
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– Seen in colonial animals
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Reciprocal altruism
– The favor is usually returned in social animals,
so is there really any true altruism???
Ch. 52 – Population Ecology
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Population is all the organisms of the same
species that simultaneously occupy the same
general area.
Human population explosion
Demography is the study of factors that affect
the growth and decline of populations
Biodemography relates to factors that influence
the distribution of a species over its range.
Density  individuals per unit volume
Dispersion  pattern of space between
individuals
– Clumped; schooling fish
– Uniform; each bird as a certain territory
– Random; trees in the forest
Demography
Age structure- results from coexistence of
generations, are male and female ratios
consistent? Is percentage surviving in
each generation consistent?
 Birthrate – also called fecundity, number
of offspring per time.
 Death rate – effected by maturity and
predation
 Life tables, survivorship curves and age
structures
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Diversity of Life Histories
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PRINCIPLE OF ALLOCATION (again)
Number of eggs per nest matches the amount of
food parents can expect to find/ number of
hatchlings that can be fed.
First age of reproduction also varies , what are
chances of surviving to be more (biologically)
mature at time of mating…. Healthier, better
parent
Number of reproductions per lifetime
– Lots of mice, frequently, all with low survival rates
– One spawning per salmon lifetime with millions of eggs
– only 1-2 will survive to reproduce
Population Growth Models
 DN/Dt
=B–D
 Change in population size over time
= the birth rate – death rate
 B is absolute births, b is births per
capita--- 34 births in population of
1000 is 0.034
 Zero population growth is when birth
rates and death rates are equal.
 2 parents, 2 children to replace them
Population curves
 Logistic
– Increases then levels off
– Idea of carrying capacity
 Exponential
– Point in time when a population is
increasing exponentially
– Bacterial growth
– Invasive species without predator
Population Limiting Factors
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Intraspecific competition
– individuals rely on the same resources
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Density dependent factors
– Food, habitat, territory, predation, disease,
toxins
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Density independent factors
– Early frost, natural disaster like flood, fire or
tornado
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Mixed situations
– Colder temps and a lack of food
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Boom or bust
– Some species have regular cycles of growth
and decline
Human Population Growth
 Exponential
growth since Plague
 Over all increase
 Many countries with actual decreses
 Age structures vary greatly –
 CARRYING CAPACITY
 Limiting factors ????
Ch. 53 – Community Ecology
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Species richness
– how many different species
– Oak, maple, hickory, aspen and pine vs. oak
and hickory only
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Relative abundance
– Ratio of species to each other
– 50:50 oak and hickory or 80:20
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Species diversity
– Species richness and relative abundance
– There are many species and each is well
represented = Good Biodiversity
Interspecific Interactions
Predator – Prey
 Competition
 Commensalism
 Mutualism
 Parasitism
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Animals
– Camouflage
– Warning colors
– mimicry
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Plants
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Thorns
Toxins
Taste
coloration
Niche
 Ecological
niche is defined as the
sum total of the organisms use of
biotic and abiotic resources
– Habitat = address
– Niche = occupation
 Fundamental
niche
– Resources it could theoretically use
 Realized
niche
– Resources it actually uses
Resources
Competitive exclusion: 2 species with
similar requirements won’t live in same
area
 Sympatric species: in same area, must
interact
 Allopatric species: populations in dif.
geographic areas
 Resource partitioning: 2 species use
resources in slightly different ways
 Key stone species: vital to maintaining
species richness
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Succession
 Succession
 transition in species
composition over time
 Primary succession  start with
lifeless soil (volcanic island)
 Secondary Succession  “starting
over” after fire or tornado
Biogeography
 Study
of why species are found
where they are found and why they
are successful there.
Chapter 54