Biology 1106 Exam 4

proximate causation

- mechanisms that produce the behavior within the animal

- what is happening in the brain that is making a fish school vs not school?

ultimate causation

- adaptive value of a behavior

- why is it beneficial for fish in one environment to school, while it is not beneficial in another environment

type of proximate causation

physiology and ontogeny

physiology

how behavior is influenced by an animal's current internal states and processes

ontogeny

how the behavior develops in an animal

types of ultimate causation

phylogeny and adaptive significance

phylogeny

why the behavior originally developed in the group of animals

adaptive significance

why is one behavior adaptive for one species but not another?

ethology

- study of animal behavior

- most ethologists use proximate causation

behavioral ecology

- study of how animals use behavior to survive and reproduce

- most behavioral ecologists use ultimate causation

associative learning

when an animal modifies its behavior because it learns to associate two stimuli or a behavior and a reward

classical conditioning

association of two stimuli (Pavlov's dogs)

operant conditioning

association of behavior and reward (Skinner boxes)

communication

when actors use signals or displays to modify the behavior of the reactors

types of communication

- acoustic

- visual

- chemical

- electric

- vibrational

- tactile (touching)

uses of communication

- mate attraction

- communication within a species

- communication across species

reproductive isolation

- prevent individuals of closely related species from mating with each other

- ex/ different species of fireflies use different light patterns and the females will only respond to the patterns of males from her own species

communication within a species

this is done to alert to the presence of food or predators, to indicate status within society, or to signal territory border

communication across species

this is done between predator and prey (prey shows predator they've seen them) or with shared vigilance between prey (prey animals warn the rest of the prey that a predator is near)

how does natural selection shape communication?

shapes displays to be as beneficial as possible; can lead to repetition, rituals, honesty, and deception

example of deceptive signal

when a blue jay imitates a hawk to drive competitors away from a food source

female mate choice

females want a few high quality mates

male mate choice

males want as many mates as possible regardless of quality

intrasexual selection

competition within one sex for the other

intersexual selection

mate choice based on desired characteristics from the opposite sex

(leads to exaggerated traits such as a peacock's tail)

what animals need to fight to win a mate

only evenly matched competitors need to fight to win a mate

sexual dimorphism

secondary sexual characteristics are traits that develop in only one of the sexes once they reach maturity that enable the to attract a mate (ie. differences between sexes)

monogamy

one male mates with one female

polygyny

one male mates with several females

polyandry

one female mates with several males

promiscuity

both males and females mate several times with different individuals

altruism

acting to increase another individual's lifetime number or offspring at a cost to one's own survival and reproduction

manipulation

recipient manipulates the donor into providing benefit (cuckoo lays egg in nest of another bird)

reciprocity

requires repeated interactions and recognition in a mutually beneficial cycle where on repays the other for help and so on

kin selection

acts that benefit blood lines thus ensuring the survival of your genes

direct fitness

fitness gained by ones own survival and reproduction

indirect fitness

fitness gained by aiding the survival and reproduction of non-descendant kin

Hamilton's rule

- c < rb

- c is cost to donor

- r is relatedness to donor and receiver

- b benefit to receiver

what does Hamilton's rule state

states that the altruistic act will be favored by natural selection as long as the cost to the donor is less than the benefit to the receiver, depending on how closely related the recipient is

aggregations

no social structure; basically just a group of animals living together

social groups

have social organizations where the individuals have stable relationships

colonies

have both social and physical structures

key stimulus/sign stimulus

a signal from the environment that triggers a stereotyped behavior

ecology

the study of how organisms interact with each other and their environment

individual adaptation (aka phenotypic plasticity)

helpful change within an individual (ex/ study schedule)(in response to unique environment)

evolutionary adaptation

inherited trait that improves the ability of individuals to survive and reproduce (ex/ cheetah's tail)

population

group of individuals of a species that are separate from other groups of that species because of factors like distance

metapopulation

group of populations that have some limited exchange between them

uniform population distribution

individuals are evenly spaced

random population distribution

result of individuals having no strong interaction with each other

clumped population distribution

usually occurs when resources are clumped

population density

the number of individuals within an area

demographics

- sex ratio

- age structure

- fecundity (birth rate per year)

- mortality (death rate per year)

generation time

average interval between the birth of an individual and the birth of its offspring

population growth rate equation

(birth rate + immigration rate) - (death rate - emigration rate)

exponential growth model

exponential growth model assumptions

assumes that there isn't any immigration or emigration and that there is no population limit

logistic growth model

has carrying capacity, or the number of individuals that can be sustained by the environment

density independent factors

- exert the same force on population regardless of the population density

- ex/ weather, catastrophes

- has negative feedback

density dependent factors

- exert greater force on growth when population is more dense

- ex/ food, predators

- has positive feedback

Allee effect

where increased population densities have increased population growth (only occurs in very small populations where its hard to find a mate

K-selected species

individuals are good survivors and competitors (humans)

R-selected species

individuals are good reproducers

rectangular population graph

even birth rate and death rate

triangular population graph

higher birth rate than death rate

inverted triangular population graph

higher death rate than birth rate

community

all the organisms that live in one place

what are communities characterized by?

they are characterized by the species within them or the species richness, species diversity, and primary productivity

ecological niche

total of all the ways that an organism uses the resources of its environment (food consumption, temperature range, moisture requirements)

fundamental niche

entire niche a species is capable of using if no other species were present

realized niche

the niche actually used by species due to the presence of other animals such as predators (deer only feed in forest because if out in the open field, predators could spot them)

two ways interspecies competition can happen

- interference competition

- exploitative competition

interference competition

two species fighting for resources

exploitative competition

one species using up all of the resources which means the second species doesn't have access to it

competitive exclusion

the inevitable elimination from a habitat of one of two different species with identical needs for resources

resource partitioning

two species can subdivide the niche by one of both of them evolving so they can coexist

resource partitioning example

when different species of lizards must share a tree, each species occupies a different area of the tree and feeds on a specific insect to allow options for the other lizards

character displacement

an advanced resource partitioning that occurs when two species evolve so they are less similar to each other; decreases niche overlap

character displacement example

Darwin's finches beaks were more similar in shape when they lived in different areas (allopatric), but were very different in shape when they lived in the same area (sympatric)

plant adaptations against herbivores

- morphological defenses

- chemical defenses

morphological defenses

thorns, spikes, small hairs, sticky secretions, toughness

evolutionary responses of herbivores to plants defenses

caterpillar evolves to be the same color as the leaf of the plant it feeds on so it is less likely to be preyed upon

animal adaptations against predators

- secondary compounds in diet

- chemical defenses

animal use of secondary compounds in diet

ex/ monarch butterfly eats milkweed so its body is filled with toxins to avert predators from eating it

animal use of chemical defenses

ex/ poison dart frogs

- warning coloration: bright colors and patterns

batesian mimicry

organism without defensive chemicals resembles a species that has them

mullerian mimicry

when two or more species with defensive chemicals look similar to one another

symbiosis

species that have evolved to live together

mutualism

both species benefit from interaction

parasitism

one species benefits, the other is harmed

three kinds of parasites

- endoparasites (internal - worms)

- ectoparasites (external - ticks)

- parasitoids: lay their eggs in or on other organisms so their young can hatch and feed on the host

commensalism

one species benefits, the other is not affected

effects of predation and parasitism

reduced competition in prey species by lowering the number of individuals competing for a resource

what is an indirect effect?

when two species affect each other through another species

ex/ presence of rodents decreases the amount of large seeds, which increases the amount of small seed for ants to feed on

keystone species

species whose effect on the the composition of communities are greater than expected for the abundance of said species (beavers)

ecological succession

tendency of communities to change from simple to complex over time

primary succession

when a community develops from nothing (ex/ where volcanoes lay down new rock)

secondary succession

when a community is disturbed but organisms remain

three components of an ecosystem

- non living things

- producers

- consumers

the water cycle steps

1. evaporation

2. condensation

3. precipitation

4. transpiration

5. groundwater