Unit 8 APBIO important terms

proximate behavior

immediate, physiological cause of behavior

ultimate behavior

evolutionary advantage of the behavior for the species

fixed action patterns

instinctive, unlearned behavioral sequence that, once started by a specific stimuli, runs to completion regardless of changes in the environment

supernormal stimulus

artificial stimulus that elicits a stronger response

• bird’s egg falls from nest → bird sees bigger egg → bird tries to get bigger egg back into nest, not small egg

imprinting

a form of non-associative learning during a “critical period” that is generally irreversible

• newborn ducks will latch onto the first thing they see when they hatch

classical conditioning

animals that are trained to elicit a natural response to some artificial stimulus

• pavlov’s dog- drools when he hears a bell because he was always fed when he heard a bell

operant conditioning

when an animal learns to associate its own natural behavior with a consequence (reward/punishment)

(different from classical conditioning, which depends on developing associations between events — operant is learning from consequences of behavior)

• dog gets a treat every time it doesn’t do something stupid = dog learns to not do stupid thing

visual communication

examples: fireflies glow to attract mates, peacocks use their tails for courting rituals, cobras inflate their hood to scare creatures

auditory communication

examples: elephants use their trunks to talk to other herds, male whales use their songs to communicate, wolves howl to call others in a pack

tactile communication

examples: dogs lick their pups to bond, baboons use touch to show affection, horses kick other horses to establish dominance

chemical communication

examples: cats rub against objects to mark them w/ their scent, ants use pheromone trails to follow each other, skunks use their smell to deter predators

bisophere

global processes — encompassing all ecosystems and areas on Earth where life exists (land, water, atmosphere)

ecosystem

energy flux and cycling of nutrients — the community of organisms interacting with their non-living (abiotic) surroundings, such as air, water, and sunlight.

community

different populations (various species) living and interacting in a particular area (zebras, lions, grasses, and trees)

populations

group of individuals of the same species living in the same area at the same time (a herd of zebra)

organism

one single, distinct living entity (one zebra).

density

number of individuals per unit of area

distribution

pattern of dispersal of individuals within a population

resources

food, shelter, water, and space

limiting factors

factors which determine the maximum potential of a population

• resources, predation, disease, etc

carrying capacity

the MAXIMUM population that can exist in a location based on limiting factors

biotic potential (r_max)

number of offspring per mating, if there are unlimited resources

survivorship curves

show age at which most individuals die in a population

type 1: high early survival, elderly death (humans)

type 2: constant mortality (birds, rodents)

type 3: high early death, low adult mortality (fish, plants, bugs)

the J-curve population growth pattern

when there are UNLIMITED resources → EXPONENTIAL GROWTH, population grows by percentage

lag phase: slow initial grown

exponential phase: rapid growth

the S-curve population growth pattern

when a population reaches the CARRYING CAPACITY of the environment, growth levels off → LOGISTICAL GROWTH

declaration phase: population growth slows down

growth rate equation

dN/dt

exponential growth equation

dN/dt=r_max(N)

logistical growth equation

dN/dt=r_max(N)(K-N/K) (k= carring capacity) (N= total population)

density INDEPENDENT factors

: regulating factors that can limit a population size, not influenced by the density of the population (everyone is affected)

• fires, floods, catastrophes

density DEPENDENT factors

regulating factors which have a stronger effect as the population density grows (larger pops are more affected)

• predation, parasitism, disease outbreak, competition

factors that determine population variation

fecundity: # of births per mating

maturity: reproductive age

parity: frequency of reproduction

r-selecting populations

they have high reproductive rates, short lifespans, low survival

ex: bacteria, roaches, rats, plantsk

k-sleected populations

prioritize slow growth, longer lifespans, few offspring but high parental care

ex: humans, elephants

autotrophs

also known as producers

• capture energy and convert it into organic molecules — through photosynthesis or chemosynthesis

chemosynthesis

energy that is stored in INORGANIC molecules (ammonia, nitrates, sulfies)

• reduces carbohydrates from CO2 and mostly happens in places where light is limited

heterotrophs

also known as consumers

• obtain organic molecules/food from other sources

herbivores

heterotroph, eats plants

carnivores

heterotrophs, eats other animals

omnivores

heterotrophs, eats plants or animals

decomposers

heterotrophs, BACTERIA AND FUNGI that feed on organic matter, waste products

detritivores

heterotrophs, ANIMALS that eat dead organic matter, waste, dead organisms

flow of energy

starts off as sunlight → photosynthesis → energy into organic molecules/food → energy in food stored in chemical bonds of fats, proteins, carbohydrates → some lost as heat/kinetic energy

• transfer of energy occurs when one organism eats another

trophic levels

feeding levels where organisms get their nutrients

producers/autotrophs → makes food for the food chain

consumers/heterotrophs:

• primary eat producers

• secondary eat primary

  • tertiary eat secondary

photosynthesis

converts light energy to chemic energy

• endergonic (absorb energy, non-spontaneous/need a constant input of energy)

cell respiration

converts chemical energy to ATP, low quality heat, movement and sound

• exergonic (releases energy, spontaneous/only requires activation energy but then continues by itself)

sequestration

carbon containing compounds are stored, not decomposed

nitrogen cycle

cycle that puts nitrogen from the air into the ground, which helps with protein formation

• bacteria is very important in this

self-regulating trophic relationships

producer populations are regulated by the consumers above them, consumer populations are regulated by availability of food below them

law of 10%

only 10% of food energy of each level is passed on to the next level in ecological pyramids

• 90% is lost as heat, movement, waste

pyramid of biomass

shows the overall MASS of food available at each trophic level

factors that determine climate

• temperature: depends on altitude and latitude

  • precipitation: how close the region is the a body of water + prevailing winds (which carries that humidity)

5 climate types

polar- north or south pole (very top or very bottom)

temperate- middle latitudes, north and south of the equator

tropics- directly or near the equator

roles in the ecosystem

• producers: produce food in the ecosystem

• primary consumers: food for the secondary + tertiary consumers

  • predators: consume primary consumers as food

keystone species

the “glue” that holds a habitat together

• can be any organism

predator keystones

keep some prey species from overgrazing the producers → saving other prey species

• starfish, otters, wolves

prey keystones

resilient prey species that serve as food for a predator population

• wildebeest, plankton, krill

engineer keystones

create/modify the landscape in ways that other organisms find useful

• beavers build dams, prairie dogs build holds in the ground

mutualist keystones

different organism that mutually benefit each other and the community

• pollinators with flowers

plant keystones

generally trees; produces food but also shelter for other species

• oak trees, saguaro cactus

species diversity

#of different species and the abundance of each

• more diversity= stronger community

  • immigration and more resources increases diversity

Island Biogeography Model

by MacArthur and Wilson

• small islands- limited resources, low diversity

  • distant islands- reduce immigration/emigration, low diversity

ecological niches

the role of a species, what it eats, where it lives, how it effects other species in the community

fundamental niche

niche where the organism could POSSIBLY survive

• theoretical, very wide and full range (pre-competitive)

realized niche

organism’s actual niche in nature

• much narrower, post-competitive, limited resources, displacement

Gause’s Competitive Exclusion Principle

no two species can have the same niche as the same time

• they will compete, one will be eliminated or partition the resource

invasive species

species that are not supposed to be in an environment but are because of immigration - they might not have a predator in the new area, causing them to overpopulate, endangering native species

ex- zebra mussles, lion fish

resource partitioning

when species adapt to their niches in a way that avoids competition from other species that have the same niche

generalist species

broad range of habitats; not selective

• advantage: dgaf when the environment changes

• broader niches

specialist species

narrow range of habitats/picky

• advantageous in old, well-established and stable environments

  • narrower niches

predator-prey interaction

when one organism (predator) feeds on another (prey)

• rely on each other to keep a stable population (eating too much=both die)

prey defense: mimicry

coloration and markings on a prey that makes them look like another organism, usually one that is more dangerous to scare predators

symbiotic interactions: parasitism

one benefits, one is harmed

types of parasites

endoparasites: inside host body

ectoparasites: on the surface of the body

vectors

organisms that transmit/transport parasites

coevolution

when species evolve in response to one another

• usually happens with parasitic, commensalistic, or mutualistic relationships

symbiotic interactions: commensalism

one benefits while the other has no benefit or harm

• barnacles on whales

  • ramora fish with sharks

symbiotic interactions: mutualism

both benefit

• bacteria in the human gut (bacteria gives nutrients, we provide a home)

  • ants on acacia tree (ants get sap, acacia tree protected from giraffes)

Simpson’s diversity index:

measures community diversity

• high scores (close to 1) → high diversity

• low scores (close to 0) → low diversity

Simpson’s diversity index EQUATION

D= diversity index

N= total # of organisms in a community

n= # of organisms in each diff. population

sigma sign= add up multiple results

D= 1-∑n(n-1)/N(N-1)