AP Bio Unit 8: Ecology

Ethology

the study of how evolutionary processes shape inherited behavior and the ways that animals respond to a specific stimuli

behavior

an organisms response to a stimulus (internal or external)

proximate cause

how a behavior occurs or how it is modified

What was the stimulus to cause the behavior (nurture)

ultimate cause

why a behavior occurs in the context of natural selection

how does the behavior help the animal survive and reproduce (nature)

innate behaviors

developmentally fixed - instictive; experience during growth has no obvious effect

learned behavors

depend on environmental influence; experience does affect these behaviors

fixed action patterns (FAPs)

a sequence of unlearned acts directly linked to a stimulus

sign stimulus

external cue

signal

a stimulus generated and transmuted from one organism to another

visual, auditory, tactile, electrical, chemcial

examples of signals

stimulus response chains

when a response to a stimulus serves as the next stimulus for a behavior

directed movements

movements toward or away from a stimulus

kinesis

a change in the rate of movement or frequency of turning movements in response to a stimulus

taxis

directional movement towards (positive) or away from (negative) a stimulus

phototaxis

movement in response to light

chemotaxis

movement in response to chemical signals

geotaxis

movement in response to gravity

learning

the modification of behavior based on specific experiences

inprinting

a long lasting behavior response to an individual

happens during a sensitive period of development

spacial learning

establishing routines based upon the special social structure of the animals surroundings

associative learning

the ability to associate 1 environmental factor with another

social learning

learning through observation and imitations of observed behaviors

foraging

food obtaining behavior; searching for, reaching and capturing food items

alturism

selfless behavior - reduces the individuals fitness but increases the fitness of the entire population

phototropism

a directional response that allows plants to grow towards or away a source of light

photoperiodism

allows plants to develop in response to day length; plant only flowers at certain times of the year

metabolic rate

the total amount of energy an animal uses in a unit of time

can be mesured in calories, heat loss, or amount of O2/CO2 used/produced

ecosystems

the sum of all the organisms living in a given area an the abiotic factors they interact with

biotic factors

living or once living components of the environment

abiotic factors

non-living physical and chemical properties of the environment

endotherms

use thermal energy from metabolism to maintain body temperature

ectotherms

use external sources to regulate body temp (ie sun/shade)

primary producers (autotrophs)

use light energy to synthesize organic compounds

hetrotrophs

rely on autotrophs because they cannot make their own food

primary production

the amount of light energy that is converted to chemical energy

gross primary production (GPP)

total primary production in an ecosystem

net primary production (NPP)

GPP - the energy used by primary producers for resp.

secondary production

the amount of chemical energy in a consumers food that is converted to new biomass

transfer is at about 10% efficienty

population

a group of individuals of the same species living in an area

dispersion

the pattern of spreading among individuals in a population

clumped dispersion

individuals gather in patches

uniform dispersion

evenly spread individuals in a population

random dispersion

unpredictable spacing

demography

the study of vital statistics of a population and how they change overtime

life table

an age specific summary of the survival pattern of a population

type I curve

low death rate during early/middle life, and a high death rate later in life

type II curve

constant death rate over the lifespan of the organism

type III curve

high death rate early in life lower death rate fro those that survive

exponential growth model

a population living under ideal conditions grows rapidly (J-shaped curve)

logistic growth model

the per capita rate of increase approaches 0 as population size nears its carrying capacity (S shaped curve)

life history

the traits that affect an organisms schedule of reproduction (when, how often, how many)

k-selection (density-dependent selection)

selection for life history traits that are sensitive to population density

seen in high density population that are close to carrying capacity (K)

r-selected (density-independent selection)

selection for life history traits that max reproductive success

seen in low density population with little competition

density-dependent regulation

as a population increases, factors can slow or stop growth by lowering BR and raising the death rate

density-independent regulation

factors that exert their influence on population size but the birth and death rate does not change

competition

\-/- relationship where individuals of different species compete for limited resources

predation

\+/- relationship where species kills and eats other species

herbivory

\+/- relationship where an organism eats parts of a plant or alge

symbiosis

where 2 or more species live in direct contact with one another

facilitation

\+/+ or +/0 where 1 species has a a positive affect on the survival and reproduction of another species

biodiversity

the variety of life in the world or in a particular habitat or ecosystem.

species richness

the number of different species

relative abundance

the proportion of each species of all the individuals in the community

Simpson’s diversity index

calculate diversity based on species richness and relative abundance and relative abundance

keystone species

not usually abundant, but other species in the ecosystem rely on them because of their important ecological niches

disturbance

an event that changes a community by removing an organism from it or by altering resource accessibility

ecological succession

the gradual process by which the species composition of a community develops overtime after a disturbance

primary succession

a series of changes on an entirely new (previously lifeless) habitat that has been colonied

secondary succession

a series of events that clears an existing community but leaves the soil intact

invasive species

a non-native species that can occupy a wide range of habitats and complete exclude native species from these habitats

biogeographical factors

large scale factors that can contribute to a range of diversity observed