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Exam 2 Ecology
Terms in this set (166)
A phenomenon in which two species descended from unrelated ancestors look similar because they have evolved under similar selective forces.
Biome and how many?
A geographic region that contains communities composed of organisms with similar adaptations.
A graph that plots the average monthly temperature and precipitation of a specific location on Earth.
The months in a location that are warm enough to allow plant growth.
The coldest biome, characterized by a treeless expanse above permanently frozen soil.
A biome densely populated by evergreen needle-leaved trees, with a short growing season and severe winters. Also known as Taiga.
A biome known for mild temperatures and abundant precipitation, dominated by evergreen forests.
Temperate seasonal forest
A biome with moderate temperature and precipitation conditions, dominated by deciduous trees.
A biome characterized by hot, dry summers and mild, wet winters, a combination that favors the growth of drought-tolerant grasses and shrubs.
Vegetation that has small, durable leaves.
Temperate grassland/cold desert
A biome characterized by hot, dry summers and cold, harsh winters and dominated by grasses, nonwoody flowering plants, and drought-adapted shrubs.
Tropical rainforest biome
A warm and rainy biome, characterized by multiple layers of lush vegetation.
Tropical seasonal forest
A biome with warm temperatures and pronounced wet and dry seasons, dominated by deciduous trees that shed their leaves during the dry season.
A biome characterized by hot temperatures, scarce rainfall, long growing seasons, and sparse vegetation.
Characterized by flowing fresh water.
A narrow channel of fast-flowing fresh water. Also known as Creek.
A wide channel of slow-flowing fresh water.
Inputs of organic matter, such as leaves, that come from outside of an ecosystem.
Inputs of organic matter that are produced by algae and aquatic plants inside an ecosystem.
An aquatic biome that is smaller than a lake and is characterized by nonflowing fresh water with some area of water that is too deep for plants to rise above the water's surface.
An aquatic biome that is larger than a pond and is characterized by nonflowing fresh water with some area of water that is too deep for plants to rise above the water's surface.
The shallow area around the edge of a lake or pond containing rooted vegetation.
The open water beyond the littoral zone, where the dominant photosynthetic organisms are floating algae.
The area in a lake that is too deep to receive sunlight.
The area consisting of the sediments at the bottoms of lakes, ponds, and oceans.
The surface layer of the water in a lake or pond.
The deeper layer of water in a lake or pond.
A middle depth of water in a lake or pond that experiences a rapid change in temperature over a relatively short distance in depth.
The vertical mixing of lake water that occurs in early spring, assisted by winds that drive the surface currents.
The condition of a lake or pond when the warmer, less dense surface water floats on the cooler, denser water below.
The vertical mixing of lake water that occurs in fall, assisted by winds that drive the surface currents.
An aquatic biome that contains standing fresh water, or soils saturated with fresh water for at least part of the year, and which is shallow enough to have emergent vegetation throughout all depths.
A saltwater biome that contains nonwoody emergent vegetation.
An area along the coast where the mouths of freshwater rivers mix with the salt water from oceans.
A biome that occurs along tropical and subtropical coasts and contains salt-tolerant trees with roots submerged in water.
protects from shoreline from cyclonic storms
A biome consisting of the narrow band of coastline between the levels of high tide and low tide.
A marine biome found in warm, shallow waters that remain 20°C year-round.
The schedule of an organism's growth, development, reproduction, and survival.
The number of offspring produced by an organism per reproductive episode.
The number of reproductive episodes an organism experiences.
The amount of time and energy given to an offspring by its parents.
The life span of an organism. Also known as Life expectancy.
Principle of allocation
The observation that when resources are devoted to one body structure, physiological function, or behavior, they cannot be allotted to another.
A growth pattern in which an individual does not grow any more once it initiates reproduction.
A growth pattern in which an individual continues to grow after it initiates reproduction.
When organisms reproduce only once during their life.
When organisms reproduce multiple times during their life.
An organism that has a life span of one year.
An organism that has a life span of more than one year.
A gradual decrease in fecundity and an increase in the probability of mortality.
A reproduction mechanism in which progeny inherit DNA from two parents.
50% from each parent
A reproduction mechanism in which progeny inherit DNA from a single parent.
100% from 1 parent
A form of asexual reproduction in which an individual is produced from the nonsexual tissues of a parent.
Individuals that descend asexually from the same parent and bear the same genotype.
Reproduction through duplication of genes followed by division of the cell into two identical cells.
A form of asexual reproduction in which an embryo is produced without fertilization.
Cost of meiosis
The 50% reduction in the number of a parent's genes passed on to the next generation via sexual reproduction versus asexual reproduction.
Red Queen hypothesis
The hypothesis that sexual selection allows hosts to evolve at a rate that can counter the rapid evolution of parasites.
Flowers that contain both male and female parts.
Individuals that possess male and female reproductive functions at the same time.
Individuals that possess male or female reproductive function and then switch to possess the other function.
Plants that have separate male and female flowers on the same individual.
Plants that contain either only male flowers or only female flowers on a single individual.
Environmental sex determination
A process in which sex is determined largely by the environment.
When the rarer phenotype in a population is favored by natural selection.
Local mate competition
When competition for mates occurs in a very limited area and only a few males are required to fertilize all the females.
The number of mates each individual has and the permanence of the relationship with those mates.
A mating system in which males mate with multiple females and females mate with multiple males and do not create a lasting social bond.
A mating system in which a single individual of one sex forms long-term social bonds with more than one individual of the opposite sex.
A mating system in which a male mates with more than one female.
A mating system in which a female mates with more than one male.
A mating system in which a social bond between one male and one female persists through the period that is required for them to rear their offspring.
When an individual that has a social bond with a mate also breeds with other individuals.
A behavior in which one partner prevents the other partner from participating in extra-pair copulations.
Natural selection for sex-specific traits related to reproduction.
The difference in the phenotype between males and females of the same species.
Primary sexual characteristics
Traits related to fertilization.
Secondary sexual characteristics
Traits related to differences between the sexes in terms of body size, ornaments, color, and courtship.
Good genes hypothesis
The hypothesis that an individual chooses a mate that possesses a superior genotype.
Good health hypothesis
The hypothesis that an individual chooses the healthiest mates.
Runaway sexual selection
When selection for preference of a sexual trait and selection for that trait continue to reinforce each other.
The handicap principle
The principle that the greater the handicap an individual carries, the greater its ability to offset that handicap.
Interactions with members of one's own species, including mates, offspring, other relatives, and unrelated individuals.
The reduced, or diluted, probability of predation to a single animal when it is in a group.
The location of an animal aggregation to put on a display to attract the opposite sex.
Any area defended by one or more individuals against the intrusion of others.
A social ranking among individuals in a group, typically determined through fighting or other contests of strength or skill.
The individual who directs a behavior toward another individual as part of a social interaction.
The individual who receives the behavior of a donor in a social interaction.
When the donor and the recipient of a social behavior both experience increased fitness from an interaction.
When the donor of a social behavior experiences increased fitness and the recipient experiences decreased fitness.
When a social interaction reduces the fitness of both donor and recipient.
A social interaction that increases the fitness of the recipient and decreases the fitness of the donor.
The fitness that an individual gains by passing on copies of its genes to its offspring.
The fitness that an individual gains by helping relatives pass on copies of their genes.
The sum of direct fitness and indirect fitness.
Selection that favors direct fitness.
Selection that favors indirect fitness.
Also known as kin selection
Coefficient of relatedness
The numerical probability of an individual and its relatives carrying copies of the same genes from a recent common ancestor.
A type of animal society in which individuals live in large groups with overlapping generations, cooperation in nest building and brood care, and reproductive dominance by one or a few individuals.
Individuals within a social group sharing a specialized form of behavior.
A sex-determination system in which one sex is haploid and the other sex is diploid.
The dominant, egg-laying female in eusocial insect societies.
The pattern of density and spacing of individuals in a population.
The range of abiotic conditions under which species can persist.
The range of abiotic and biotic conditions under which a species persists.
A measure of the total area covered by a population.
Ecological niche modeling
The process of determining the suitable habitat conditions for a species.
The range of ecological conditions that are predicted to be suitable for a species.
Species that live in a single, often isolated, location.
Species with very large geographic ranges that can span several continents.
The total number of individuals in a population that exist within a defined area.
In a population, the number of individuals in a quantified area or volume.
The spacing of individuals with respect to one another within the geographic range of a population.
A pattern of population dispersion in which individuals are aggregated in discrete groups.
Evenly spaced dispersion
A pattern of dispersion of a population in which each individual maintains a uniform distance between itself and its neighbors.
A pattern of dispersion of a population in which the position of each individual is independent of the position of other individuals in the population.
The movement of individuals from onearea to another.
Counting every individual in a population.
Counting a subset of the population.
Area and volume-based surveys
Surveys that define the boundaries of an area or volume and then count all the individuals in the space.
Surveys that count the number of individuals observed as one moves along a line.
A method of population estimation in which researchers capture and mark a subset of a population from an area, return it to the area, and then capture a second sample of the population after some time has passed.
Lifetime dispersal distance
The average distance an individual moves from where it was hatched or born to where it reproduces.
The absence of a population from suitable habitat because of barriers to dispersal.
Habitat corridor —
A strip of favorable habitat located between two large patches of habitat that facilitates dispersal.
Ideal free distribution
When individuals distribute themselves among different habitats in a way that allows them to have the same per capita benefit.
When a larger population is broken up into smaller groups that live in isolated patches.
Basic metapopulation model
A model that describes a scenario in which there are patches of suitable habitat embedded within a matrix of unsuitable habitat.
Source-sink metapopulation model
A population model that builds on the basic metapopulation model and accounts for the fact that not all patches of suitable habitat are of equal quality.
Landscape metapopulation model
A population model that considers both differences in the quality of the suitable patches and the quality of the surrounding matrix.
The study of populations.
In a population, the number of new individuals that are produced in a given amount of time minus the number of individuals that die.
Intrinsic growth rate (r)
The highest possible per capita growth rate for a population.
Exponential growth model
A model of population growth in which the population increases continuously at an exponential rate.
The shape of exponential growth when graphed.
Geometric growth model
A model of population growth that compares population sizes at regular time intervals.
Factors that limit population size regardless of the population's density.
Factors that affect population size in relation to the population's density.
Negative density dependence —
When the rate of population growth decreases as population density increases.
Positive density dependence —
Also known as inverse density dependence or the Allee effect.
When the rate of population growth increases as population density increases.
A graphical relationship that shows how decreases in population density over time lead to increases in the mass of each individual in the population.
Carrying capacity (K)
The maximum population size that can be supported by the environment.
Logistic growth model
A growth model that describes slowing growth of populations at high densities.
S-shaped curve —
The shape of the curve when a population is graphed over time using the logistic growth model.
The point on a sigmoidal growth curve at which the population achieves its highest growth rate.
Age structure —
In a population, the proportion of individuals that occurs in different age classes
Tables that contain class-specific survival and fecundity data.
Stable age distribution
When the age structure of a population does not change over time.
Net reproductive rate
The total number of female offspring that we expect an average female to produce over the course of her life.
Generation time (T)
The average time between the birth of an individual and the birth of its offspring.
Cohort life table
A life table that follows a group of individuals born at the same time from birth to the death of the last individual.
Static life table
A life table that quantifies the survival and fecundity of all individuals in a population during a single time interval.
When a population grows beyond its carrying capacity.
A substantial decline in density that typically goes well below the carrying capacity.
Regular oscillation of population size over a long period of time.
Delayed density dependence
When density dependence occurs based on a population density at some time in the past.
A pattern of population growth in which the population size initially oscillates, but the magnitude of the oscillations declines over time.
Stable limit cycle
A pattern of population growth in which the population size continues to exhibit large oscillations over time.
A model that is designed to predict a result without accounting for random variation in population growth rate.
A model that incorporates random variation in population growth rate.
Variation in birth rates and death rates due to random differences among individuals.
Variation in birth rates and death rates due to random changes in environmental conditions.
The process of breaking up large habitats into a number of smaller habitats.
The phenomenon of dispersers supplementing a declining subpopulation that is headed toward extinction.
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