EEB2244E Final

fragmentation

asexual reproduction: organism splits into two mature individuals

adiabatic cooling

warm air rises, expands, cools holds less water vapor so it rains (equator/ITCZ)

tropical rainforest biome

- annual temp >20C

- ITCZ (equator)

- biodiverse

- poor soil (rapid cycling nutrients)

temperate rainforest biome

- annual temp 5-20C

- wet

boreal forest biome

- annual temp

climate envelope

suitable climate conditions constraining a species geographic range

sequential hermaphrodites

animals where one sex functions then switches to the other through physiological transformation; takes days, irreversible

Hermaphrodism occurs when

cost of reproductive failure > cost of producing male and female functions

monogamy

- one male, one female; serial or life long

- favored by equal parental contribution, even resource distribution, inability to monopolize >1 female

social behavior: altruism

(-,+) cost to donor, benefit to recipient; does not lead to direct fitness

apparent competition

impacts resembling competition but not due to shared resources

- shared predator or parasite

time delays in population cycles

- τ

- degree of cycling=r*τ

- period of cycle=4τ

- between breeding and offspring addition (gestation)

- storage of resources

- anything causing population growth to be impacted by density in the past

true predators

consume whole, live animals or plants: mostly carnivores, seed-predators, and filter feeders; short association, many victims

Batesian mimicry

harmless organism looks like harmful one; mimic benefits, model does not

Mullerian mimicry

two or more distasteful or poisonous species come to resemble one another; all poisonous

infection resistance

the ability of a host to prevent an infection from occurring

hydrologic cycle

movement of water through ecosystems and atmosphere, driven by evaporation, transpiration, precipitation

phosphate cycle: aquatic

- phosphate assimilated and excreted/decomposed

- phosphate precipitates and forms sediment

- sedimentary rock is later uplifted moving phosphate back to terrestrial systems

circulation in ponds and lakes

- summer stratification: surface water heats up and floats

- autumn overturn: surface water cools and sinks

- winter stratification: surface freezes and floats, 4C water densest at bottom

- spring overturn: surface water warms to 4C and sinks

*4C water densest

wetland biomes

- freshwater: swamps (emergent trees), marshes (emergent non-woody vegetation), bogs (acidic water, low nutrients)

- saltwater: marshes (non-woody vegetation, highly productive) and mangrove swamps (salt tolerant trees, roots in water, prevent erosion) estuaries

detrivores

break down dead organic matter (detritus)

microcosm

isolated community; manipulative study; has control and treatment

solar equator vs geographic equator

- solar equator: latitude receiving direct sun rays

- geographic equator: 0 degrees latitude

- solar equator at geographic equator on equinoxes, at 23.5N (Tropic of Cancer) on June solstice, at 23.5S (Tropic of Capricorn) on December solstice

adiabatic heating

cool air sinks, condenses, warms holds more water vapor so its dry (30*N/S)

Hadley cells

atmospheric convection cell in which air rises at the equator and sinks at 30° N/S

Intertropical Convergence Zone (ITCZ)

solar equator where Hadley cells meet

trade winds, westerlies, and easterlies

- global winds caused by Hadley cells, Ferrel cells, Polar cells

- wet at 0, dry at 30N/S

Coriolis effect

Causes moving air and water to turn left in the southern hemisphere and turn right in the northern hemisphere

ocean gyres

- gravity pulls water away from equator

- clockwise in N hemisphere, counterclockwise in S hemisphere

ocean upwelling

upward movement of ocean water where surface currents move away from western coastlines; cold high nutrient water brought to the surface of west coasts = high productivity

El Nino-Southern Oscillation (ENSO)

every 3-7 years trade winds reverse/oscillate causing warm water to move in opposite direction and cold water upwelling to be opposite

maritime vs continental climates

maritime more stabilized (less seasonal temp variation) and higher rainfall

continental more extreme variation and lower rainfall

rain shadow effect

wet, warm air moves up windward side of mountain causing cooling air and rain, air falls down leeward side of mountain absorbing moisture as it warms drying the land

tropical seasonal forest/savanna biome

- consistently >20C

- very seasonal precipitation

subtropical desert biome

- annual temp >20C

- dry

- not seasonal

- low plant life

woodland biome

- annual temp 5-20C

- dry summers

temperate seasonal forest biome

- annual temp 5-20C

- acidic soil

- trees lose leaves

- seasonal precipitation

cold desert/temperate grassland biome

- annual temp 5-20C

- dry season

tundra biome

- annual temp

soil determining factors

- climate

- organisms

- relief (topography)

- parent material (bedrock)

- time

soil layers

O: organic matter

A: broken down organic material, fine rock

E: leached inorganic material

B: weathered rock, inorganic materials

C: less weathered, large parent rock

R: bedrock

exponential growth model

- continuous population growth, unlimited resources

- Nt=N0e^rt

- r=growth rate=births-deaths

geometric growth model

- seasonal population growth, unlimited growth

- Nt=N0λ^t

- λ=e^r

- lnλ=r

- doubling time=time it takes to double population=t2=ln2/r

negative density dependence

increase in population density causes decrease in population growth

- due to competition

positive density dependence

decrease in population density causes decrease in population growth

- Allee effect

- due to not being able to find mate or poor foraging

optimal population growth

- K/2

- population growing at highest rate

logistic model

- population growth model with limited resources and competition

- dN/dt=rN(1-N/K)

- K=carrying capacity

- inflection pt=max dN/dt= when N=K/2

survivorship curves

- Type I: high mortality late in life

- Type II: constant mortality (birds)

- Type III: high mortality early in life (oak tree)

cohort approach

follow a group of same aged individuals through lives

- sessile organisms

static approach

count all individuals of all ages at a point in time

- mobile and long lived organisms

- must be able to identify organisms

competitive exclusion

species with same niche cannot coexist

fundamental niche vs realized niche

- fundamental niche: range of abiotic conditions species can exist

- realized niche: range of abiotic and biotic conditions a species can exist; includes competition

endemic

species that is only found in a small area

capture mark recapture

capture and mark a number of animals (M), release, recapture a number of animals (n), record number with marks (x)

- M/N=x/n

clustered dispersion

- due to clustered resources, social behavior, limited dispersal

- V/M>1

evenly spaced dispersion

- due to depleted resources, competition, territoriality

- V/M

random dispersion

- no deterministic processes

- position of organisms independent of each other

- V/M=1

dispersal

movement of individual from one area to another

dispersal limitation

species limited geographically because it cannot physically get to another suitable area and no other factors

population structure

subdivision of organisms into subpopulations living in suitable habitat patches of habitat surrounded by matrix

basic metapopulation model

suitable habitat patches of equal quality embedded within matrix

source-sink model

- source: high quality habitat, self sustaining, provides dispersers

- sink: low quality habitat, rely on dispersers

landscape model

variation in matrix quality and habitat conductivity

ideal free distribution

individuals distribute among different habitats in response to resources and competition

fast life history/r-selected

- early maturity

- short lifespan

- high number of offspring

- little parental care

- traits to increase population growth

slow life history/K-selected

- late maturity

- long lifespan

- small number of offspring

- high parental care

- traits to increase competitiveness

Grime's Plant Classification

- competitors: high competition, adjust resource allocation, fast growth, early reproduction, low energy to offspring, low stress and low disturbance environments (oak trees)

- ruderals: high disturbance, fast life history, fast growth, early reproduction, energy to producing more offspring, seeds long lived and well dispersed (weeds)

- stress tolerators: high stress, slow life history, slow growth, low energy to offspring, vegetative reproduction, resource conservation (tundra plants)

Lack's hypothesis

selection will favor the clutch size that produces the most surviving offspring

determinate growth vs indeterminate growth

- determinate growth: stops growing once it initiates reproduction

- indeterminate growth: continues growth after reproduction

senescence

gradual decline in fecundity and increase in mortality as an individual ages

semelparity

organisms reproduce only once during their life

- lots of energy required for reproduction, frequent catastrophic events

iteroparity

repeated reproduction throughout lifetime

phenological mismatch

climate change causing temperature rise before photoperiod change so species timing is out of sync

vegetative propagation

asexual reproduction: immature organisms from nonsexual organisms

spore formation

asexual reproduction: release of reproductive cells

binary fission

asexual reproduction: forms two daughter cells from one

advantages of asexual reproduction

- offspring assured without other organism

- adapted to parent's environment

- parent passes on all genes

budding

asexual reproduction: 1 mother (larger) and 1 daughter (smaller) organism (hydra and yeast)

parthenogenesis

asexual reproduction: parent produces embryo without fertilization

advantages and disadvantages of sexual reproduction

+ genetic variation

- sex organs and mating behavior costly

- mating behavior risky

- mating not guaranteed

- cost of meiosis: only half the genes passed on

red queen hypothesis

sex and genetic recombination provide moving targets for pathogen evolution

avoiding Muller's ratchet

asexual organisms cannot purge mutations, they accumulate

sexual organisms can avoid mutations: meiosis loses mutations

what biologically defines "male"?

size and mobility of the gamete- smaller, more mobile

sex determination

genetic determination: chromosomes

environmental determination: temperature dependent

dioecious

separate male and female plants

hermaphrodism

reproductive organs of both sexes in the same individual; most plants

monoecious

one plant, separate male and female flowers

perfect flowers

one flower: male and female parts

simultaneous hermaphrodites

animals with both male and female functions at the same time

self-fertilization

an individual's male gametes fertilize its own female gametes; build up of mutations, unfavorable

out-crossing

breeding with other individuals

promiscuity

- both sexes have multiple partners

- favored by inability to monopolize resources, unpredictable environment

polygamy

- having more than one mate at a time

- favored by patchy resources

polygyny

- 1 male, many females

- females prefer few best males, males w best territory

polyandry

- 1 female, many males

- female looks for superior sperm or mating gifts, unpredictable environment-> maximize egg production

polygyny threshold model

polygyny when territory variation so great that some females better off in polygyny than monogamy

sexual dimorphism

phenotypic difference between males and females

- need for larger/more offspring or eggs -> females larger

- males compete physically for mates -> males larger

sexual selection

individuals differentiate among potential mates based on traits; sex that makes larger investment will be more discriminating

- intrasexual: within sex competition for mates

- intersexual: mate choice

good genes hypothesis

choose a mate with superior genotype

good health hypothesis

choose the healthiest mate