Vocab Flashcards
Population ecology
The study of factors that cause populations to increase or decrease
Age structure
A diagram used to predict how a population would grow over the next few years
Intrinsic growth rate
A populations maximum for potential growth
Exponential growth model
Produces a j-shaped curve
Not limited by density dependent factor
Density dependent
Factors that limit a population
Carrying capacity
Used to describe a populations upper limit
Logistic Growth Model
Produces a S-shaped curve
Will reach an upper limit called its carrying capacity
Overshoots
Describes a population beyond its carrying capacity
Die-offs
Describes a population below its carrying capacity
R-selected species
A species capable of rapid exponential growth
K-selected species
A species limited by resources and competition
Type I survivorship curve
High survival through most of an individuals life span, but then individuals start to die in large numbers as they approach old age. (Elephants)
Type II survivorship curve
A relatively constant decline in survivorship throughout most of the individuals life span. (Birds)
Type III survivorship curve
Low survivorship early in life with few individuals reaching adulthood (Dandelions)
Intraspecific
Competition between members of the same species
Interspecific
Competition between 2 or more species for the same limited resource
Competitive exclusion
When 2 species competing for the same limiting resource cannot coexist
Resources partitioning
Utilizing limited resources at different times or places
Predation
Occurs when a predator feeds on all or part of another organism known as its prey
Co-evolution
Occurs when species interact over a long period of time and influences changes in each other’s gene pools
Parasitism
When one organism gains energy by living on or inside a host organism
Mutualism
When 2 organisms interact in a manner that is beneficial to both
Commensalism
When an interaction benefits one species but has little to no impact on the other (lichen)
Ecological succession
The gradual change in species abundance and diversity after unpredictable events
Primary succession
The establishment of a biotic community from a previously lifeless terrain
Secondary succession
Where a disturbance in the ecosystem has damaged or removed part of the established community but leaves the soil in place
Pioneer species
First to move into the ecosystem and begin the colonization process
Biodiversity
Refers to the variety of species, the genes they contain, and the ecosystems they live in.
Natural capital
Examples include food, fuel wood, energy, and medicines
Species richness
The number of species in a given area
Species evenness
The relative proportion of different species in a given area
Mutation
Random changes in the DNA of a cell
Genetic diversity
Variability in the genetic makeup among individuals within a single species
Natural selection
Results in a population that contains a greater proportion of organisms better adapted to certain environmental conditions
Fitness
an organism’s ability to survive and reproduce
Adaptation
Traits that improve an individual’s fitness
Geographic isolation
When geologic or climatic events separate populations
Reproductive isolation
An inability to pass new traits between separated populations
Speciation
The formation of 2 species from one because of divergent natural selection in response to changes in environmental conditions
Extinction
When an entire species disappears from earth
Background extinction
Normal extinction of various species
Mass extinction
A significant rise in extinction rates above the background level
Range of tolerance
Determines whether an organism is living in its fundamental or realized niche
Fundamental niche
The suite of abiotic conditions under which a species can survive, grow, and reproduce
Realized niche
The range of abiotic and biotic conditions under which a species actually lives
Native species
A type of species that lives and flourishes in a particular environment
Specialist species
A type of species with a narrow niche who eats from one food source
Generalist species
A type of species with a broad niche since it can eat a variety of food
Invasive species
A nonnative species introduced to a new environment
Keystone species
It’s disappearance has a large impact on the community (large impact on the community)
Indicator species
A species that provides an early warning that damage to an ecosystem is occurring
