Module 1: Ecology Flashcards
What is the Method of Ruling Theory?
- intellectual attachment to a “ruling theory”
- starting with an explanation, then looking for the data to support pre-conceived ideas
- giving the illusion of strength to a theory
What is the Method of Working Hypothesis?
- not the ideal
- they come up with a hypothesis and then a conclusion is made before looking at the data
- intellectual attachment/interpretation that favors the hypothesis
The Method of Multiple Working Hypothesis
- effort is distributed among various hypotheses (the researcher is not attached to a single group of data-less intellectual attachment)
- allows for multiple factors to be a part of the explanation
- promotes thoroughness in research
What is the difference between sequential and simultaneous causes?
- sequential: happens in chronological order, with one state moving to another because of a certain factor
- simultaneous: multiple factors move one state to another at the same time, some might have more of an impact than others
What are the limits of human studies?
- bias in experiments causes a lot of problems
- random assignment, stratified (age and severe risk for covid is consistent across all participants), observer-blind, placebo-controlled
What are the criteria for something to be considered living?
- cellular organization = all cells are surrounded by a membrane and have organization within that enclosure
- metabolism = cells are able to take in energy and process it and turn it into a form of usable energy
- homeostasis = cells are able to maintain internal conditions (ex. cooling/heating)
- growth and reproduction
- heredity = cells are able to pass on traits to the next generation
- response to stimuli = cells are able to respond to their environment
What is the correct Binomial Nomenclature?
genus (larger taxonomic group) THEN species (smaller, more related group that can interbreed)
biological species concept
groups of interbreeding natural population that are reproductively isolated from other groups
morphospecies concept
groups that are identified based on size shape or other morphological features
phylogenetic species concept
groups are identified based on the evolutionary relationships that they have; a smallest diagnosable group contains descendants of a single common ancestor
biodiversity
the number, variety, and variability of living organisms in the biosphere
Population
a group of organisms of the same species living in the same place
Community
all populations of different species living in the same place
Ecosystem
all populations of different species living in the same place
Biome
ecosystems that share major similarities
Biosphere
the global ecosystem (the largest classification
Ways to calculate population size and density
- quadrat
- mark and recapture
- indirect methods (looking at things that the animal has left behind)
Quadrats
- best for slow-moving or immobile organisms
- count individuals within the borders
- multiple quadrants are used for the most accurate estimate
- based on a small area and then multiplied
- assuming equal distribution may not be a good estimate
mark and recapture
- animals with higher levels of mobility
- capture a certain number of individuals within the population
(number marked first catch x total number of second catch)/number marked second catch = N
limits:
- too small
- harm to animals
- the animals that are captured = the most likely to be captured
clumped species distribution
nearest neighbors are nearer, on average, than a random dispersion pattern would predict
used for:
- safety
- social function
- resource distribution
random species distribution
nearest neighbors are as near as predicted if all individuals were randomly placed within the focal boundaries
used for:
- not common in animals
- most likely seen in wind-dispersed seeds
uniform species distribution
nearest neighbors are further away, on average, than a random dispersion pattern would predict
- even spacing
- nesting/territorial behavior
- aggression based on distance
Type I survivorship curve
- most likely to die of old age (low juvenile death)
- large animals without predators
- stable environments (no competition for resources
k-selection = parental investment in offspring
Type II survivorship curve
- the probability of dying is the same at every age
- straight, diagonal line
type III survivorship curve
- very young have the greatest probability of during
- produce many offspring
- little to no care from parent
- surviving into adulthood = surviving into old-age
Energy Budget
balancing energy intake with use of energy for metabolism
- obtaining food for energy (dependant on the size of the organism)
- growth (dependant on stage of life)
- reproduction (dependant on strategy)
- care of offspring
- energy storage
Semelparity
- species that reproduce once in a lifetime
- usually the individual will die soon after the event
- produce more offspring per event
- all resources are devoted to the reproductive event
Iteroparity
- species that reproduce repeatedly during their lifetime
- lifetime offspring production repeat
- longer care for offspring (if the species provides parental care)
demographic model
- low adult survival rates favor withholding resources for future reproduction
- if we have a species that is only reproducing once = high die-off rates
bet-hedging
- variable adult survival favors multiple reproductive events
- various chances for the species as a whole to reproduce
The Lack Clutch
- David Lack (1947)
- birds should optimize the number of their offspring by optimizing their number of surviving offspring
- too many offspring = parents unable to take care of the offspring, some will die
- too few offspring = fewer than can be taken care of, lower total number of offspring
K-Selected Species
- fewer offspring = more parental support
- selected by stable, predictable environments
- close to carrying capacity
Characteristics:
- mature late
- greater longevity
- increased parental care
- increased competition
- fewer offspring
- larger offspring
R-Selected species
- unpredictable or changing environments
- live below carrying capacity
Characteristics:
- mature early
- lower longevity
- decreased parental care
- decreased competition
- more offspring
- smaller offspring
density-dependent factors
- food availability
- availability of nesting sites/space
- aggression
- stress due to overcrowding
- predators
- diseases
positive density-dependent factors
- species growth rate benefits from increasing densities
Example: - obligate parasites
- wildebeest use it for herd protection
negative density-dependent factors
- population growth is negatively impacted
Examples: - crowding
- predators
- competition
density-independent factors
- the effect is not based on the number of individuals in a population
examples: - weather (natural disasters like a forest fire)
- random disturbances
What caused the extinction of the Wolly Mammoth?
- climate change (warming at the end of the last ice age)
- human hunting
- other environmental changes (lack of water or food)
- low genetic diversity
What influences the change in the total fertility rate?
- early marriage/age at birth of a first child
- education
- voluntary family planning (availability of birth control)
- government policies
Changes in the death rate
declined from 1.95% to 0.85%
life expectancy
- increased from 55.43 (1968) to 72.57 (2018)
- improvements in the production of food and distribution
- cleaner water
- advances in medicine and health care
Covid Trend
decline in birth rate - gradual increase - “baby boom”
biotic potential
the maximum growth rate that a population can achieve in an unlimited environment
environmental resistance
difference between biotic potential and the actual rate of increase
carrying capacity
the maximum number of individuals that an environment can support
defense mechanisms
- physical: camouflage-coloration and body shape
- behavioral: playing dead, schooling/flocking
- mechanical: thorns, shells
- chemical: toxicity
aposematic coloration
- warning coloration
- usually very bright or easy to see
- warns of unpleasant taste or toxicity
Batesian mimicry
- a harmless species imitates a harmful one by mimicking their warning coloration
- benefit for the species that does not produce the toxin without the cost of energy expenditure
Mullerian mimicry
- multiple species share the same warning coloration
- all have defenses
emsleyan/mertensian mimicry
- deadly organism mimics a less dangerous one
- extremely rare
niche
the way that an organism occupies an area and used the resources therein (space, water, temperature, and mating)
fundamental niche
entire niche that the species is capable of using
realized niche
actual niche that the species occupies
principle of competitive exclusion
- no 2 species can exist in the same niche if that niche has limited resources
symbiosis
close interaction between individuals of different species
commensalism
- a type of symbiosis
- one species benefits
- other neither benefits or is harmed
mutualism
- a type of symbiosis
- two species benefit from the interaction
parasitism
- a type of symbiosis
- organism that lives in or on another living organism and derives nutrients from it
- host is harmed
amensalism
- a type of symbiosis
- one species is harmed
- other species neither benefits or is harmed
keystone species
a species that has a much greater impact on the distribution and abundance of the surrounding species than its abundance and total biomass would suggest
foundation species
a species that has a strong role in structuring the community (often primary producers)
top-down influence
- top predators
- an important role in the trophic cascade
bottom-up influence
the presence of a species at the bottom of the food web that has a major effect on the community structure.
intermediate disturbance hypothesis
- moderate levels of disturbance can foster greater diversity than either high or low levels of disturbance
primary succession
where no soil exists when succession begins (eruption of volcanoes)
secondary succession
begins in an area where soil remains after a disturbance (forest cleared by a wild fire)
pioneer species
annual plants grow and are succeeded by grasses and perennials (the earliest species)
intermediate species
shrubs, then pines, and young oak and hickory begin to grow
climax community
- mature
- establishing themselves
facilitation
- prepare the ecosystem for later species
- early arrivals to the community facilitate the appearance of later species
- change the environment to make it more favorable
inhibition
- physically blocking/changing the environment to make it inhospitable
toleration
- species tolerate the current conditions but don’t have an impact on the establishment of later species
how do we distinguish between innate and learned behaviors?
- observation
benefits of innate behaviors
- no risk for mistakes (come by environmental ques)
- hard-wired into the system (if an animal is able to do the behavior, it will always be the same)
- genetically programmed
benefits to learned behavior
- more flexible and dynamic
- can change and adjust based on the conditions
- also can change by the individual
reflex action
- involuntary, rapid stimulus
- animals with learned behavior can also have innate behaviors
kinesis
- undirected movement in response to stimulus
- random, non-directional
orthokinesis
increased or decreased speed in response to a stimuli (random movement gives less time in an unfavorable environment)
klinokinesis
-increased turning behavior
- randomly find a more hospitable environment
taxis
directed movement towards or away from a stimulus
phototaxis
movement towards or away from light
chemotaxis
moving towards are away from chemical signals
geotaxis
gravity (moving towards or away from)
fixed action pattern
- movement continues even after the stimulus is removed
- the fish experiment (the red belly is the stimulus that elcits the aggressive behavior of the fish)
migration
- long-range seasonal movement of animals
- evolved, adapted response to resource availability
obligate migration
species always migrates
facultative migration
species chooses whether to migrate or not
incomplete migration
same individuals in the population migrate while others do not
foraging
- searching for and exploiting a food resource
- optimal foraging behaviors maximize fain while minimizing energy expenditure
- favored by natural selection
imprinting
- occurs at a particular age or stage of life
- rapid and independent of species
habituation
animal stops responding to a stimulus after a period of repeated exposure (the stimulus offers no important information)
selfish behavior
- only one animal benefits
- makes evolutionary sense
altruistic behavior
- one animal’s actions benefit the other
- doesn’t make evolutionary sense
the selfish gene theory
- individual sacrifices may exist if the benefit goes to related individuals that share the same genome
- genes that are not selfish will disappear (be selected against)
- selfish behavior (genetically speaking) will be favored by natural selection
cooperative behavior
- both animals benefit
- makes sense evolutionarily
kin selection
- the lowering of individual fitness enhances the reproductive fitness of a relative
- protects shared genes (a bee protecting the hive)
reciprocal altruism
- the expectation of a return of altruism from the individual
- individuals in the group must repeatedly encounter each other (social interaction is a must)
- cheaters must be punished by a certain mechanism (fairness in animals)
