BIOL 2 EXAM 1: CH 43-47

State Tinbergen’s 4 questions that should drive studies of animal behavior

(developmental) how is the behavior acquired over time? (mechanistic) how is behavior caused? (evolutionary) where/how did behavior arise in the past? (adaptive) how does behavior enhance survival/reproduction of individuals?

explain how foraging involves trade-offs between nutrients acquired and the costs of energy required and risk

its a compromise of benefits of getting food & the energy spent getting it/risk of getting eaten

explain how differences in the reproductive strategies of males & females can foster sexual selection for certain characteristics in males

females produce many offspring to mate more & males produce limited offspring

determines who reproduces (struggle for mating success)

sexual selection

different mating systems

polygyny, polyandry, monogamy, promiscuity

males mate with multiple females

polygyny

females mate with multiple males

polyandry

one male & one female

monogamy

no pair bonds btwn sexual partners (multiple mating w/ multiple people)

promiscuity

costs of living in groups

inc. risk of being spotted by predators, inc. intraspecific competition for food & mates, inc. risk of parasitism/disease, inc. potential for inbreeding/inbreeding depression

benefits of living in groups

info transfer & access, foraging efficiency, reduced risk of predation, cooperative hunting, inc. likelihood of finding mates

explain how altruism could’ve evolved and its benefits to the individual as well as the group

altruism could’ve evolved for the return-benefits. the groups benefitted by helping individuals receive future help from others/contributing to the survival

group of individuals of the same species within a given area that have the potential to interbreed and interact with each other

population

organisms are clustered together in groups. this may reflect a patchy distribution of resources in the environment. this is the most common pattern of population dispersion (ex:wolves)

clumped

organisms have an unpredictable distribution. this is typical of species in which individuals don’t interact strongly. (ex: dandelions)

random

organisms are evenly spaced over the area they occupy

uniform

J-shaped curve, unlimited

exponential growth model

S-shaped curve; populations per capita growth rate gets smaller as population size approaches a maximum (carrying capacity)

logistic growth model

how does carrying capacity affect exponential growth?

the growth rate slows down and levels off, preventing the population from growing indefinitely at an exponential rate

can be affected by factors that affect birth & death rates such as biotic factors like competition and predation

density-dependent factors

can be affected by factors that affect birth & death rates such as abiotic factors and environmental factors (severe weather conditions/fires)

density-independent factors

curve in which there are few offspring born & there’s good parental care so that most of the individuals live to an old age (ex: elephants, humans, large mammals)

type I

organisms die at an equal rate at all ages; there is some parental care (ex: birds & rodents)

type II

many offspring are produces bc many don’t survive in the first few days; if they do survive they have few predators (ex: mussels, grasses, oysters)

type III

what growth is this?

rapid growth

what growth is this?

slow growth

what growth is this?

zero growth

what growth is this?

negative growth

produce one huge batch of offspring then die

semelparity

produce several smaller batches of offspring distributed over time

iteroparity

species with a capacity for a high rate of population increase

• high intrinsic rate of increase (r)

• small body size & short life span

• early reproduction & reproduce quickly

• many small offspring

• little to no parental care/protection

• type III survivorship curve

• semelparous

• inhabit unstable, unpredictable environments

r-selected species

reproduce later in life & have small number of offspring w/ fairly long life spans

• low intrinsic rate of increase (r)

• large body size

• late reproduction

• few large offspring

• high parental care

• type I or II survivorship curve

• iteroparous

• inhabit stable environments at/near carrying capacity

K-selected species

group of subpopulations that are separated by space but interact as individual members move from one subpopulation to another

metapopulation

inhabit relatively high quality habitat in terms of reproduction & survival & are viable without an influx of immigrants, positive population growth, net exporters

source subpopulation

inhabit relatively poor quality habitat & aren’t viable without an influx of immigrants; negative population growth without immigration, net importers

sink subpopulation

study of how different species within a specific habitat interact with each other

community ecology

how do biologists measure species richness?

count the number of different species present

how do biologists measure species evenness?

count the number of different species present & the number of individuals of each species

most abundant

dominant species

effect that far exceeds abundance

keystone species

non-native organisms that upset the balance

invasive species

complete description of the role a species plays in its environment & of its requirements, both abiotic & biotic

ecological niche

includes full range of climate conditions & food resources that permit individuals in a species to live

fundamental niche

actual range & habitats used by a species

realized niche

result of competitive interaction which one species is prevented from occupying particular habitat/niche

competitive exclusion

a process in which species w/ overlapping niches diverge over time to minimize the overlap

resource partitioning

competition between individuals of different species

interspecific competition

lions and cheetahs competing for the same prey

example of interspecific competition

competition between individuals of the same species

intraspecific competition

two oak trees growing too close, fighting for sunlight & nutrients

example of intraspecific competition

close interspecific relationship between 2 dissimilar species (includes parasitism, mutualism, & commensalism)

symbiosis

colonization of a new & previously un-inhabited area

primary succession

re-establishment of communities following disturbance

secondary succession

major events in water cycle

driven by the process by photosynthesis, respiration, exchange, sedimentation and burial, extraction, & combustion (can be fast or slow) human activities (burning fossil fuels, changing land use, & using limestone to make concrete) have a tremendous impact

major events in carbon cycle

fixation, ammonification, nitrification, & denitrification. human activities (making fertilizers & burning fossil fuels) have significantly altered the amount of fixed nitrogen in Earth’s ecosystem

major events in nitrogen cycle

weathering, fertilizer, excretion and decomposition, dissolved phosphates, geologic uplift. humans contribute to the excessive levels of phosphorus by their use of fertilizers & raising hogs

major events in phosphorus cycle

how does the coupling of photosynthesis & respiration result in the cycling of carbon?

in photosynthesis, light drives the reaction of CO2 and water to form carbs and O2. in respiration, the opposite happens, cycling carbon back to CO2

explain the problems when excess phosphorus & nitrogen make their way into ecosystems

too much nitrogen & phosphorus in the water causes algae to grow faster than ecosystems can handle. significant increases in algae harm water quality, food resources & habitats, & decrease the oxygen that fish & other aquatic life need to survive

explain where there’s typically less biomass and fewer individuals & species at the top of a food chain than at the bottom

the energy transfer from one trophic level to the next, up the food chain, is like a pyramid; wider at the base and narrower at the top, bc of this inefficiency, there’s only enough food for a few top level consumers, but there is a lot of food for herbivores lower down on the food chain

total primary productivity

gross primary productivity

GPP - R

net primary productivity

efficiency with which organism converts what it has eaten into its own biomass

ecological efficiency

refers to short-term changes in the atmosphere

weather

refers to atmospheric changers over longer periods of time & is affected by factors such as Latitude Elevation (Altitude) wind & ocean Topography

climate

describe how the Coriolis Effect deflects moving parcels of air in the Northern & Southern Hemispheres

due to the earths rotation, essentially making air currents curve as they travel across large distances

why do the Northern & Southern Hemispheres have opposite seasonal patterns?

because earths tilt on its axis as it orbits the sun

how do ocean currents affect climate?

currents regulate global climate, helping to counteract the uneven distribution of solar radiation reaching earths surface

elevated terrain often pushes air up in the atmosphere acting as a lifting mechanism, which aids in creating even more precipitation

effects of topography & altitude on climate

• layers

• biodiversity

• nutrient cycling

• temperate, tropical & boreal

forest biome

• grasses

• herbivores

• fire adaptations

• seasonal changes

grassland biome

• semi-arid

• regions of dense-spiny shrubs w/ tough evergreen leaves

• mild, rainy winters & long, hot dry summer (btwn 430-40 latitude)

• maintained by periodic fires

chaparral (scrubland)

• water scarcity

• xerophytic adaptations

• nocturnal activity

desert biome

• permafrost (permanently frozen layer on/under earth’s surface)

• migration & hibernation

• fragile balance

• less precipitation falls here than in deserts

tundra biome

• generally limited by temp & moisture

• classified by climatic factors & types of primary producers

terrestrial biome

• most __ organisms don’t have to deal with extremes of temp/moisture

• their main limiting factors are the availability of sunlight, concentration of dissolved oxygen, & nutrients in water

aquatic biome