All Flashcards
Low Virulence?
results in low mortality and usually asymptomatic
Heard immunity
negative pathogen population growth leads to pathogens going exctinct
mixotrophic
can consume compounds for energy as well as photosynthesize
Do parasites alter host behavior?
Yes, some parasites alter their behavior in ways that benefit transmission and reproduction of the parasite
disease
a typical condition in living organisms that cause some type of physiological impairment
Pathogens
parasites that cause disease
vectors
organisms that transmit pathogens without becoming infected themself
Does the transmission have to be direct?
It may be direct, or indirect
verticle transmission
parent to offspring
horizontal transmission
same generation
Three subpopulations of disease
susceptible (Uninfected), infected, and immune
predator satiation
a tactic used by prey species in which the prey reduces their individual probability of being eaten by occurring at very high densities
Batesian mimicry
nontoxic species exhibits coloration similar to that of a noxious species living in the same area
Mullerian mimicry
several species of toxic/noxious animals share similar warning colouration
aposematic colouration
bright colouration in prey that advises the fact that prey have toxins or are distasteful in some way
Animal display
many prey use camouflage to avoid predation
consumptive effects
direct effects of predation on prey populations throughout capture and consumption of prey
non-consumptive effects
changes as a consequence of predator presence even when prey is not killed
Plant defense - constitutive
produced continually regardless of environment
Plant defense - Induced
increase rapidly in response to herbivore damage
Chemical defense - Toxins
Toxins - chemicals that kill, impair or repel an animal
Chemical defense - Digestion
reducing substances - inhibit the breakdown of plant proteins by digestive enzymes
Plants C:N ration
Plants have a higher carbon ratio to nitrogen
Resisitance
makes the individual less likely to be eaten
Tolerance
reduce the harm associated with being eaten
exploitation
interaction between populations that enhances the fitness of one individual while reducing the fitness of the exploited individual
character displacement
competition between species living together can evolve differences between them even though they can be nearly identical living apart
do species always have the same competition?
no,
competition coefficient variables are not always fixed for each species
Competitive equivlence
species may be completely equal in their competitive abilities such that the outcome of competition is not predictable
incomplete exploitation of resources
two competing species fail to approach their carrying capacity for a variety of reasons
non - equilibrium conditions
competitive exclusion is not instantaneous it is a process that may take generations to occur. essentially saying two species who compete for a limited resource cannot coexist at constant population values
spatial heterogeneity in the strength of competition
if heterogeneity is in any of these factors (food availability, disease, predation, and climate conditions across landscapes) we can expect species coexistence in some locations
competitive exclusion principle state
that two species with identical niches cannot co-exist indefinitely
the Lotka - Volterra model predicts what?
that species co-exist when intraspecific competition is stronger for both species than interspecific competition
Exploitative competition
involves competition to secure resources first
interference competition
involves direct aggressive interactions between individuals
Intraspecific competition
competition among members of the same species
Interspecific competition
competition between two different species
density-independent
things related to chance, such as floods and fires.
density-dependent
factors that limit growth based on the density of the population (usually due to limited resources) this then hits carrying capacity (K) which is the maximum number of individuals an area can support
frequency-dependent selection
where the fitness of genotype depends on its relative abundance within a population
do population sex ratios change?
Yes, they can change depending on the relative fitness of different sexes within a population
what is a sex ratio
the relative frequency of each sex type in a population
what does the distribution of a population reflect?
this reflects its history of survival, reproduction, and potential for future growth
Survivorship curve 1
relatively high rate of survival among youth and middle-aged individuals, followed by a high rate of mortality among the aged
Survivorship curve 2
constant rate of survival throughout life producing a straight-line pattern of survival
Survivorship curve 3
extremely high rates of mortality among the young followed by a relatively high rate of survival
what is age distribution
calculates differences in the proportion of individuals in each age class (assumes differences In numbers from one age class to the next due to mortality and assumes the population is stable in size)
Static life table
Records age at death of many individuals over a narrow period of time (requires an accurate estimate of age at death)
Cohort life table
identifies individuals bort at the same time and keeps records from birth (easy to interpret but often difficult or impossible to collect this data)
Life table
is a table used in ecological bookkeeping, It is a device used to record the age-specific survival and death or mortality rates in a population
Why is the sex ratio kinda off sometimes
sex ratios are equal at birth, males may disperse more often and farther than females as adults. For some species, the sex of their offspring is dependent on habitat (reptiles with heat)
Species abundance
species abundance in the places they are generally occurring is widely distributed within a region, continent, or ocean. However, species living at low population densities generally have smaller restricted distributions
Who are the most abundant species
Species that are least threatened by extinction and typically have extensive geographic ranges, broad habitat tolernaces, and large local populations at least somewhere within their range
Habitat tolerances
This is related to the range of conditions in which a species can live
Three things that affect rarity
Geographic range (extensive vs restricted), habitat tolerance (broad vs narrow), and local population size (small vs large)
self-thinning
a natural process that occurs in plant populations with the average number of plants decreasing as the average plant size increases
when do species thrive
when they match optimum growth conditions described by a species niche. As well as with conditions near survival, one expects reduced growth and population size
Population declines with an increase in organism size
Smaller organisms have a larger population size, bigger organisms have a smaller population size
clumped
mutual attraction creates clumped or aggregated patterns of distribution. individuals have a much higher probability of being found in some areas than others
Regular
produced when individuals avoid each other or claim exclusive use of a patch of landscape. individuals are uniformly spread
Random
neutral responses contributed to random distributions. individuals within a population have an equal chance of living anywhere within an area
Small scale
refers to disturbances of no more than a few 100m over which there is little environmental change significant to the organism under study
Large scale
refers to an area of substantial environmental changes or patterns over an entire continent or along a mountain slope environmental gradients
Characteristic of a metapopulation
- Metapopulations are subpopulations of a larger population. 2. subpopulations are connected by the movement of individuals from one subpopulation to another. 3. any subpopulation can go extinct and be re-colonized repeatedly over time. 4. the risk of a subpopulation extinction is generally greatest for small populations which usually occur in small patches on the landscape. 5. density-dependent and density-independent population dynamics occur within each subpopulation
what causes metapopulations
result from interactions between species’ biology and the landscape on which it lives
Stream population maintained
through a dynamic interplay between upstream/downstream dispersal called the colonization cycle
Colonization cycle
the dynamic view of stream populations in which downstream/upstream dispersal and reproduction have major influences on the stream population
Drift
this is the movement of organisms being pushed won a stream. It is naturally occurring and organisms within the lake have to swim upstream to counteract this and stop them from being washed out
Spates
a sudden flood of water
What is numeric response a change of?
it is a change of density of predator populations in response to increased prey density. Some predators with much lower reproductive rates also show a strong numeric response, Numerical response to prey density are almost entirely due to dispersal
Expanding populations
those that are in the process of increasing their geographic range
Dispersal
Is (typically) a permanent exodus from one population into another
migration
is the seasonal movement of individuals from one location to another
What does dispersal allow for
it allows the persistence of metapopulations and has important consequences for natural communities. Dispersal is different than migration. Dispersal can also alter species distribution and local population densities.
conditions defined by a species niche will only be found in specific locations
conditions defined by a species niche will only be found in specific locations
How do landscapes differ?
environmental conditions, prey distributions, and other critical axes of niche
What does the physical environment limit
it limits the geographic distribution of a species
Ecological density
incorporates the concept of niche, in that not all of the conditions found within a given area will contain the niche requirements of a particular species. The ecological density would be the number of individuals per unit of suitable habitat
absolute density
this is the number of individuals in a population per unit of area.
population density
is the number of individuals per unit area
Ecological filters
They are abiotic and biotic controls that influence how species are sorted from a regional pool into local communities, including physical environment attributes, such as soil type, and microclimate, and biological interactions such as predator-prey interactions and mutualism.
how can populations be divided
they can be delineated using natural boundaries or artificial ones defined based on societally important areas such as countries or parks
Niche partitioning
often means narrowing. Allowing more competing species to occupy overlapping fundamental niche space. This may also include a niche shift such as using a marginal portion of its fundamental niche in response to changes in local conditions
Fundamental niche
defines the physical conditions under which a species might live in the absence of interactions with other species
Realized Niche
refers to more restricted conditions. Interactions among species (aka competition) may restrict environments in which a species can persist
What is a niche
it is NOT a physical location, it is an abstract representation of the environmental conditions necessary for a species to survive
n
n = environmental factors necessary to species survival and reproduction
Equilibrium strategy
combines high juvenile survival, low numbers of offspring, and late reproductive maturity
opportunistic strategy
low juvenile survival, low numbers of offspring, and early reproductive maturity
Periodic strategy
low juvenile survival, high numbers of offspring, and late maturity
Trade offs
Survivor ship (especially among juveniles), fecundity (number of offspring produced), and generation time (age at maturity)
where do competitive plants occupy
They occupy places of low disturbance intensity and low stress. Under these conditions low stress and low disturbance they have the potential to grow well. eventually, they will compete as they grow usually for sunlight, nutrients, or water. The ones who survive are selected for strong competitive abilities
interference competition
organisms directly alter the behavior of other organisms to gain access to resources
self-incompatibility
incompatibility for a plant to fertilize itself, must receive pollen from another plant to produce
intrasexual selection
compete among themselves for mates
intersexual selection
members of one sex constantly choose mates from members of the opposite sex on the basis of some particular trait
sexual selection
process of sexual selection resulting from differences in reproductive rates among individuals as a result of differences in their mating success
secondary sexual characteristics
characteristics of males and females not directly involved in the process of reproduction (colours, ordaments, etc)
promiscuity
having multiple different partners
mating system
they are the social, and sexual structure of a population
sexual selection
selection of mate for particular traits
haplodiploid
males develop from unfertilized eggs and haploid. females develop from fertilized eggs and are diploid
castes
groups of individuals that are physically distinct and engage in specialized behavior
cooperative breeders
live in groups with many adults cooperating during the process of producing and/or rearing offspring
eusocially
complex levels of social behavior. 1. individuals of more than one generation living together. 2. cooperative care of the young. 3. division of individuals into sterile and nonreproductive and reproductive castes
reciprocated altruism
individuals do not have to be related to each other for altruism 2to be evolutionary stable - tit for tat -
broad parasitism
is when animals can sometimes be tricked into being altruistic (there are not any obvious means of preventing this from occurring or where the cost of prevention would be to great)
phenotype evolution
- must have a genetic basis that can be transmitted to the next generation. 2. the expression of the trait must be flexible and situational
out of the four, cooperation, altruism, spitefulness, and selfishness, which are favored by natural selection and which are not?
cooperation and selfishness are favored whereas altruism and spitefulness are not
group selection
individuals may act counter to their own personal interest for the betterment of the group
social interactions are between?
Donor - performs a given action (threat or help) and recipient - the individual who recognizes the given behavior
Kin selection
a natural selection process that favors traits that help an organism’s relatives reproduce, even if it comes as a cost to the organism’s own survival
inclusive fitness
fitness is determined by individual survival and reproduction plus the survival and reproduction of individuals who share the same genes
interspecific variation
is a variation that occurs when comparing individuals of different species
intraspecific variation
the genetic and phenotypic diversity within a species
Ethology
they study the relationship between organisms and the environment that is mediated by behavior
functional response
relationship between food availability and feeding rate
which has a higher photosynthetic rate? Shade or sun plants
shade plants
What is LCP
Light compensation point, is it the amount of light necessary for a plant to have zero net oxygen production
what will differ among plant species
The irradiance (level of light intensity) or PFD required to reach Pmax (maximum rate of photosynthesis) will differ among species
Photosynthetic response curve
under ideal growing conditions (abundant water, proper temp/humidity, enough nutrients) if the light intensity of alight shining in a plant is increased the plants rate of photosynthesis will gradually increase and then level off
What is limited in plants and animals
the rate at which they can take in energy and nutrients
catadromous fish
spawn in salt water then spend most of their time in freshwater
anadromous fish
Spend some of their juvenile development stages in freshwater before they migrate to the ocean, they spend most of their life there and then return to freshwater when it is time to spawn
WUE
water use efficiency is the biomass of plant tissue per gram of water used
How do animals conserve water
Producing concentrated urine/feces, condensing and reclaiming water vapor in their breath, as well as restricting activities to a certain time
metabolic water
water that is released during cellular respiration
water acquisition
how an organism aquire water
evapotranspiration
water molecules adhere to each other. as one molecule leaves it tugs in a neighboring molecule pulling them closer to the pores
two challenges that were faced when organisms moved out of water
- Potential massive losses of water in the environment through evaporation. 2. reduced access to replacement water
How do terrestrial plants and animals regulate their internal water balance
by balancing water acquisition against water loss
when does matric pressure increase
the strength of the matric depends on the distances between particles. As the distance increases matric pressure decreases
vapor pressure
related to the quantity of water in the air
Hypoosmotic
The organism’s body water content is higher. so water exits and the solution comes in. The external environment is hypertonic
Hyperosmotic
organism body water concentration is lower, water comes in, solute comes out. The external environment is Hypotonic
Isotonic
this refers to a solution having the same solute concentration as the outside area
isosmotic
an organism’s body/solute equals the external environment. They are at equilibrium and the osmotic pressure is the same
Osmosis
the movement of water across a semipermeable membrane. Water moves down the concentration gradient. Only SOLUTION moves
Diffusion
The movement of a solute through a semipermeable membrane, goes from high to low. only SOLVENT moves
salinity effects what
the relative aridity of aquatic environments
Aridity
the lack of moisture so dry
Countercurrent heat exchange
This is when vascular structures reduce the rate of heat loss to the surrounding aquatic environment
thermal neutral zone
the range of temp over which the metabolism of a homeothermic animal does not change (the area in which the organisms can adjust easily)
High albedo
reflects more light than it absorbs
Low albedo
absorbs more light than it reflects
cushion growth
growth that happens close to the ground to provide shelter from winds
do animal setts and burrows have their own climate?
Yes this is called microclimate
Endotherms
rely on metabolic heat to elevate internal temp
Ectotherms
control their body temp through the use of external energy sources
Homeotherms
can keep their body temp stable despite changes in the external environment - Keeps a fairly consistent internal temp
Poikilotherm
they have a body temperature that varies in response to changes in the external environment
Evaporation
You will always lose heat
Radiation
this light is responsible for most of the warmth you feel from a light source
convection
heat flow between a solid body and a moving fluid such as wind or flowing water
conduction
is the movement of heat between objects in physical contact
How do organisms regulate their body temp
They regulate their temp by manipulating heat gain and heat loss
Hyperthermophile microbes
they are the most heat-loving microbes
Thermophilic microbes
microbes that can live at high temps
psychrophilic microbes
these are cold-loving marine bacteria that live in water around Antarctica
Acclimation
involves the physiological not genetic change in response to temperature and is usually reversible
adaption
involves a change in the gene pool of the population through differential reproductive successes of individuals
Do plants photosynthesize faster or slower in colder weather
slower
Law of toleration
abundance and disturbance of an animal can be determined by the deviation between the local conditions and the optimum site of conditions
Range of tolerance
the range of tolerance is the entire range of conditions over which a species is able to survive (good or bad)
Principle of allocation
As a population adapts to a particular set of environmental conditions its fitness in other environments is reduced. (all organisms have access to limited energy supplies. each organism has a finite quantity of resources that it can use for all necessary life)
Can organisms live and thrive in any environment?
No that is not possible
what holds more dissolved oxygen, cold or warm water?
cold water
what are two limits in thermal stability in an aquatic environment due to temp change?
The altered temp will affect organisms living in water and the amount of dissolved oxygen in the water
Riparian vegetation
the vegetation growing along rivers and streams. They provide shade which insulates the stream environment
what keeps water temp stable?
waters high capacity to absorb heat energy without changing temperature
Latent heat of evaporation
the largest amount of heat absorbed by water as it evaporates
latent heat of fusion
the heat energy that water gives up to its environment as it freezes
which fluctuates more, air temp or water temp?
Air temperature
Can albedos change?
yes
what factors affect the ground temp
the colour of the ground and the presence of any snow or vegetation that covers the ground
what does temp influence
it influences the growth of individuals and the distribution of a species
assortative mating
individuals choose mates similar to themselves (positive assortative mating). or mates that are different (negative assortative mating)
sympatric speciation
A disruptive selection of traits that causes groups of individuals (even within a single population) to differ greatly in phenotypes. This is usually due to assortative mating and can evolve into reproductive isolation
allopatric speciation
single groups spatially divided
parapatric speciation
population expands into a new habitat within the preexisting range of the parent species
sympatric speciation
single parent population forms genetically distinct subpopulations by natural selection
hybrid sterility
occurs of the hybrid develops normally but is unable to produce viable gametes (post-zygotic)
hybrid inviability
results if zygotic development is abnormal and the developing hybrid dies before sexual maturity (post-zygotic)
ecological isolation
when two individuals are physically separated such that they are unable to encounter each other (pre-zygotic)
Post zygotic isolation
this is a part of reproductive isolation and occurs after the zygote has been formed
prezygotic isolation
is a part of reproductive isolation that prevents two individuals from forming a zygote
reproductive isolation
is a set of barriers that prevent different species from breeding and producing healthy offspring (this is a critical requirement of species, you need reproductive isolation)
ecocline or cline
gradual change in phenotype/genotype of a species over a large geographical region. individuals of a species on opposite ends of the spectrum may appear quite different from each other with no specific location at which individuals become different
biological species concept
where populations of organisms able to interbreed and produce viable fertile offsprings are classified as belonging to the same biological species
morphology species concept
classifying organisms belonging to the same species by their morphological features. this is useful when organisms do not sexually reproduce or are extinct
speciation
physical/ecological processes interact with selection and drift to create new species
founder effect
a decrease in genetic diversity associated with the formation of a new small population
what is the dominant factor that influences the rate of evolution
population size, with drift causing a more rapid evolutionary change in smaller populations loss of genetic variation through drift is a significant concern for a small population
parallel evolution
isolated species in similar habitats evolve similar traits as similar environmental pressures lead to the selection of similar traits
directional selection
when an extreme phenotype is favored over the average. As a consequence differences in survival and reproduction alter the average phenotype
stabilizing selection
tends to favor the average phenotype, the population tends to sustain the same average phenotype over time decreasing the frequency of the extreme phenotype
genetic drift
a change in the frequency of an existing gene variant in a population due to a random chance
macroevolution is caused by what?
natural selection and random processes such as genetic drift, if accumulated can lead to genetic divergence leading to speciation (aka macroevolution)
what does the Hardy-Weinberg principle state?
in a popukation at random in the absence of evolutionary forces allele frequencies will remain constant variations in allele frequencies over time lead to microevolution
evolutionary change
a process by which organisms’ heritable traits change over generations allowing them to better adapt to their environment
phenotype plasticity
this is when an organism can change their phenotype without altering its genes, this is in response to its environment
phenotypic variation
occurs when the expression of a gene is changed in response to the environment (combined effect of genes and environment)
adaptations
these are an evolutionary process that changes autonomy, physiology, or behavior resulting in a population’s increased ability to live in that particular environment
fitness
relative genetic contribution of individuals for the future generation
species diversity
a combination of the number of species and their relative abundance
species richness
the number of species in the community
alpha diversity
measure of local diversity
beta diversity
measure of differences among the communities within the region or landscape
gamma diversity
measure of regional or landscape density
guild
a group of organisms that all make their living in a similar way
species evenness
relative abundance of species, can be thought of as the inverse of dominance
species composition
the number of different species in an environment and how many individuals of each species are present
complementarity
based on niche theory; production is highest in ecosystems being most fully exploited
Facilitation
some species enhance growth of others
sampling effect
based on assumption that functions of communities with low species evenness are driven by dominant species
ecological network
is a description of interactions that occur among co-occurring species in a community
competitive hierarchy
some species are beter competitors than others
keystone species
species with disproportionately strong influences on community structure
primary succession
occurs on newly exposed geological substates following any situation where new substrate is exposed or created
pioneer community
plants that colonize the area within the first 20 years after a glacier retreat
secondary succession
follows after a disturbance removes members of an existing community without destroying the soil (ex fire)
what promotes a high diversity?
intermediate levels of disturbance. Studies show that both high and low disturbance levels lead to reduced species diversity with intermediate levels promoting a higher diversity
why can a community be stable
due to lack of disturbance or community resistance/resilience in the face of disturbances
nonequilibrium theory
environment maintains or exists in a constant state of disturbance
resistance
ability to maintain structure and/or function in face of potential disturbance
resilience
ability to recover from disturbances
insurance hypothesis
diversity increases stability due to increased probability of there being some species able to cope with any particular disturbance.
what does diversity act as
diversity acts as a buffer, it buffers a community from the potential consequences of a disturbance or any environmental change
what do community changes cause during succession
community changes during succession include increases in species diversity and changes in species composition
is succession a process or an event
it is a process
chrono sequencing
a set of ecological sites that are similar in many ways but represent different ages
time its takes for each of the successions to take place
Primary succession (glacier), 1500 years. Secondary succession (fire), 200 years. succession in intertidal communities 1.5 years and succession in desert streams can occur on a scale of weeks
what drives ecological succession
facilitation (positive interactions between species), tolerance, and inhibition (slowing down or stopping a reaction)
facilitation model
proposed that many species attempt to colonize newly available space but only species with particular characteristics can establish
tolerance model
proposed that the initial stages of colonization are not limited to a few pioneer species
pioneer species
they modify the environment so that it becomes less suitable for them and more suitable for species found later in successional stages
inhibition model
proposed that any species can colonize the area during early stages of succession - when they occupy the environment it makes it less suitable for other species
biotic invaders
species that establish a new range in which they proliferate, spread, and persist to the detriment of the environment
