AP Bio Unit 8

Behave

• A response to stimuli from enviroment

• contruibutes to homeostasis

• Essential to fitness of a species

• Individual contribution to gene pool

• Essential to aquiring nutrients; use of recources

• Essential to mating/ maintaning a speices

Innate Behavior

• Born with it (genetic component)

• Requires no learning

• Nearly all in a speices exhibit it

Learned Behavior

• Modifieed by experience

• Requires diff. stimuli

Causation

Is the “how” and “why” of behavior

Proximate causation

The “how” - Physiological component ( sex hormones adrenaline “fight or flight”) can include nature and nurture.

Ultimate causation

the “why”- evolutionary component. Natural selection at work (mating rituals, survival behavior).

Genetic Component

• Maze savvy rats mated with maze savvy rats yeild maze un-savvy rats ( opposite ture as well)

• Genetically identical twins have identical genome- separated at birth then reunited later in life: similar temoerment personalities, interests.

• In our lab- c. elegans & the genes for learning.

• Mice have gene responsible for maternal care. was isolated & disabled in lab: mice no longer cuddled & kept young warm.

Enviorment component (“nurture”)

cross-fostering studies: one species placed in care of another (much different) at very early age- as get older tent to display some of other species characteristics.

Fixed action patterns

sequences of unlearned acts directly linked to a simple stimulus called a sign stimulus (ex. geese egg rolling).

Migration

Long-range 2-way movements,

• celestial navagation (sun/ North Star)

• when day/ night may use circadian clock

• if cloudy may use earth’s magnetic field (homing pigeon/ magnet mangnetite in head of migrating species

Communication

Recognizable visual, auditory or chemical stimuli that elicit a response.

Speices recognition

courtship displays recognized by 1 species

• blue footed booby

• albatross

• helps prevent mating between species/ isolate genes with in a speices

• actions initiate stimulus- response chain

• Dancers & dialogue (honeybee dance laugage calling to warn of danger

Pheromones

Chemicals used to communicate location, danger, sex attractants during mating season

Learned Behavior

• Behavior modified by experiences

• 2 types: non-associative & associative

Non-associative learning

Habituation

(simplest type of learning)

ex. work at rocky quarry with frequent explosions jump at first eventually no reaction

Associative learning

Connection between a stimulus and a response

Imprinting

a mix between innate and learned behavior

• Learned social interactions between different species

• Has a critical period where attachment forms

Classical conditioning

• Ivan pavlov & pavlov’s dogs

• a paired association between 2 diff. types of stimuli

• the animal forms association

the experiment:

1. meat powder presented to dog, dog salvates (unconditioned stimulus= meat powder, unconditions respond= salivates)

2. bell rung at time of presenting meat

3. eventually only the bell ringing caused dog salvation

Operant Conditioning

“Trial and error” learning B.F. Skinner & the “Skinner Box”

• animals learn to associate a reward with behavior

• very important learning for most vertabretes and in the “wild”- natural enviroment for feeding (training fog, bird, catching butterfly

Spatial Learning

Learning to use landmarks to help find food , nests, ect.

• Using the landmarks, a cognitive map is created

• prevents need from moving from landmark to landmark

• ex. Ground bee nest

• Honey bee waggle dance (a combination of behaviors)

• Associations that animals make likely to be ones they come across and provide selective advantage

Pill Bugs

• Terestrial crustations (breathe with gills)

• decomposers

• example organisms for orientation movement

Taxis

Movement directly toward or away from a stimulus

• positive taxis= towards

• Negative taxis= away

Kinesis

Random movement in an enviorment- undirected “searching” for desired stimuli. If kenisis results in disired or undesired stimuli can become taxis.

Cognition and Problem solving

The most complex types of learning requires:

1. Awareness

2. Reasoning

3. Recollection

4. Judgement

This type of learning can be social

• Juvinials observing the experienced

• can involve a sensitive period where the learning is critical to take place

• if miss critical period wont learn properly

Foraging behavior

Not only finding food but energy expended finding it (distance to, battle to capture/ kill, risk of injury/ death in process)

Optimal foraging model

Natual selection favors behaviors minimizing cost & maximizing benefit.

• frruit fly gene analysis (forager gene) provides this low-density “siter” allele high density “rover” allele.

Mating behavior

More than a partner; also carring for offspring, competition for mates, most genetically “fit” partner

• most species promiscuous- no pair bonding, many partners

• ensures offspring/ survival of species; care of young may be compromise

if pair bonding occurs can be either:

• monogamous

• polygamous

• polygyny

• polyandry

Monogamous

One male & one female don’t generally display sexual dimorphism (size/ color/ ornamentation diff.)

Polygamous

1 individual of one sex mating with several of other sex

Polygyny

most common- one male many females

Polygandry

less common- one female many males. Morphologic diff. seen in females

Parental care

Young helpless & need constant food- often monogamous relationship (one guards other hunts)

Polygamy

Gets down to “certainty of paternity” or “whos your daddy”

• basically if you know they’re your offspring your more likely to care for them

Aitruism

Species can exhibit “selflessness”

• reduce an individuals fitness (passing his/her genes on to the next generation) by putting oneself in danger.

• increases fitness of other individuals in population

• ex. ground squirrle sees hawk stays above ground to warn others- risk of predation but others safe

Inclusive fitness

total effect individual has on sending its genes on to the next generation

Visual signals

color & mating behavior/ color and danger

Audible signals

warning call, mating song

Tactile signals

touch- part of mating rituals

Electrical signals

electric fishes- sharks/ rays others can generate weak electrical signals

Chemical signals

Pheromones- for locomotion/ mating/ teritory

Community

Assemblage of populations living close enough for possible interactions

Individualistic concept

nothing more than species living in the same space at the same time

• some recent research supports ( with global warming)

Holistic concept

many accept currently- speicies function as an integrated unit. Need all to function properly

Community Interactions

Interactions with in a community are interspecific.

• can do 3 things:

1. Help those involved (+ effect)

2. Harm those involved (- effect)

3. Have no effect on those invoulved (0 effect)

Commpetition

((-/-) both harmed in some way) species can coexist but commpetition for recourses will limit growth, survival, & space they occupy. (weeds, lawn)

Compettitive exclusion

if 2 species compete for the same limiting recource, both can NOT coexist

Niche

• All the ways an organism uses it’s recources (biotic & abiotic)

• Fundemental = what could occupy in perfect world

• realized=what it does occupy

Species can not coexist in a community of their niches are identical

Recource partitioning

enambles similar species to occupy same area using different set of recources.

predation

(+/-) predator kill & eats prey. Predation skills and prey avoidance skills refined through natural selection- need reproductive success.

Predator adaptations

acute senses, claws, teeth, poison, agility

Prey adaptations

cryptic coloration- camoflouge: aposematic coloration- bright colors associated with toxins produced or ingested & expressed by prey.

Mimmicry

two resemble each other

batesian= harmless mimics harmful

mullarian= 1 harmful mimics markings of another harmful

Herbivory

• (+/-)

• An herbivore eats plants of alge

• has led to evolution of plant mechanical (spines/ thorns) & chemical (toxins) defenses & adaptations by herbivores

Symbiosis

2 or more speices living in initmate contact (very close/ direct)

Parastitism

(+/-) 1 organism(parasite) derives nourishment from another organism (host) which is harmed in the process (ticks, tapeworms)

Mutualism

(+/+) interaction that benefits both species (lichen, mycorrhizae, termites & digestion)

Commensalism

(+/ 0) 1 species benefits & other is neither helped nor harmed - hitch hiker barnacles

Facilitation

(+/+) or (+/ 0) 1 species cna have positive effects on another species with out direct intimate contact (black rush in salt marshes)

Ecological succession

Trend in species & diversity of an area from simple to complex. Different speices alter the enviorment, allowing others to take hold.

Primary succession

occurs on bare, lifeless substrate ( rock, sandy beach, volcanic lava bed)

Pioneering species

Are first speices ot inhabit area

• must be very tolerant of harsh abiotic conditions

Secondary Succession

occurs in areas that have been disturbed - soil remainns intact (fire, clear- cutting for logging/ forestry)

Tolerance

(1st to inhabit) pioneering organisms must be hardy / able to withstand abiotic conditions

Facilitation (part of ecological succession)

Pioneering (or early species in case of secondary Succession) alter abiotic conditions (soil/ PH) facilitation growth of less tolerant organisms

Inhabition

1 speices that facilitated the growth of another may eventually be out- competed (growth inhabited) by another speices

Speicies Diversity

Speices diversity of a community is the variety of organisms that make up the community.

• 2 components: Speices richness & relative abundance

Speices richness

is the total number of different species in a community

Relative abundance

is the proportion each species represents of the total individuals in the community

Ecotone

2 ecosystems overlap.

communities with a higher diversity are:

• more productive & more stable in their productivity

• better able to withstand & recover from enviromental stresses

• more resistant to invasive species (not native) organisms that become established outside their native range

Trophic levels

shows feeding relationships between individuals with in a community

• Huge cey factor in community dynamics

• Decomposers “feed” on every trophic level

Food web

Is a branching food chain with complex trophic interactions

Energy Hypothesis

suggests that length is limited by inefficient energy transfer (about 90% lost at each level, supports 10%)

Dynamic stability hypothesis

long food chains are less stable than short ones.

• fluctuation at lower trophic levels are magnified at upper ones

Dominant Species

the most abundant or the most biomass in a community

• may be able to outcompete for limited recources

• may have afaptioms to better avoid disease / predation

Keystone species

Have profound effects on communities

• some construct their own ecosystems (beavers)

• some profound effects numbers at each trophic level

Bottom- up model

Proposed an undriectional influence from lower to higher trophic levels

• presence or absence of mineral nutrients determins primary producers which influence all other trophic levels

Top- down model

(AKA trophic Cascade) proposes that control comes from the trophic level alone

• predators control herbivores which in turn controls primary producers

Biomani Pulation

Human influence on speices at different trophic levels to help nestone polluted communities

Primary productivity

The rate at which photosynthetic organisms build organic compounds (fix atmospheric carbon into sugars) & synthesize oxygen.

Gross primary productivity (GPP)

total amount produced in any given period

Net primary productivity (NPP)

total amount produced minus what plants use for respiration

* Yes plants have a mitochondria & do cell respiration @ hight, low sun, and during points of hight ATP demand

Population Ecology

A population is a group of individuals of a single species living in the same general area

• populations are described by their boundaries & size

Density

Is the number of individuals per unit or voulume (if in liquid- bacteria or algae)

Dispersion

is the pattern of spacing among individuals withing the boundaries of the population

• Density is result of interplay between processes that add individuals to a population & those that remove individuals

Immigration

is the influs of new individuals dorm other areas

Emigration

is the movement of individuals ou of population

Population size

In most cases, impractical or impossible to count all individuals in population

• sampling techniques used to estimate densities & total population sizes

Mark- recapture method

• scientice capture, tag & release a random sample of individuals (s) in a population

• marked individuals are given time to mix back into the population

• Scientists capture a second sample of individuals (n) & note how many of them are marked (x)

• population size (N) is estimated by: N=(sn/x)

Clumped (dispersion)

• Individuals aggregate in patches

• common clumped dispersion may be influenced by recource availibity (uneven or scarce) and social behavior (travling together)

Uniform (dispersion)

• evenlu distributed

• may be influenced by social interactions such as territoriality the defense of a bounded space against other individuals (compettition for recourses)

• common when closely spaced plants compete for recources (water, sunlight)

• some plants (walnut) secrete toxin into soil to prevent others

Random (dispersion)

the position of each individual is independent of other individuals

• Not common unless verry little species interaction

Species survival

• can be influenced by biotic or abiotic factors

• Abiotic are “non-living” interactions- many times enviormental interaction

• Biotic are living interactions

Density Dependent

Result of more individuals in population is an example of negative feedback control over population.

• population increases

• mortality can increase

• reproduction rates can deline

Density Independent

Factors unrelated to population that affected growth

• often enviormental factors like drought, cold winter, hurricane, volcano.

• cause growth curve of population to appear erratic not a smooth curve

Exponential Growth Model

• An idealized situation with abundant recources & reproduction at Physiological capacity

• allows for understanding about a species potential capacity to increase & the conditions required for it

• immigration= emmigration

• R-selected speices

• Births exceed deaths

• J shaped curve

Logistic Growth Model

• Tru J-shaped curve unrealisitc in most cases

• immigration not equal emmigration

• Not infinite recources

• Population rate will decrease as pop. reaches carying compacity (denoted with a “k” on graphs)

Predator- prey interactions

many times speices populations interconnected

• snowshoe hare feeds on willowbark. if quantity decreases hare feeds on high fiber, birth rate reducing diet. this follows 10 year cycle (rise/ fall in pop. rates)