Features of Populations Flashcards
Survivorship Curve
a line that displays the relative survival rates of a cohort—a group of individuals of the same age—in a population, from birth to the maximum age reached by any one cohort member
Type I survivorship curve
- What is it?
- What kind of loss?
- What kind of species typically exhibit Type I?
- Pattern of survival over time in which there is high survival throughout most of the life span, but then individuals start to die in large numbers as they approach old age. Species range from exhibiting excellent survivorship until old age.
- Late Loss
- K-selected species tend to exhibit type I or type II curves
Type II survivorship curve
- What is it?
- What kind of loss?
- What kind of species typically exhibit Type I?
- Pattern of survival over time in which there is a relatively constant decline in survivorship throughout most of the life span. Species range from exhibiting a relatively constant decline in survivorship over time.
- Constant Loss
- K-selected species tend to exhibit type I or type II curves
Type III survivorship curve
- What is it?
- What kind of loss?
- What kind of species typically exhibit Type I?
- Pattern of survival over time in which there is low survivorship early in life with few individuals reaching adulthood. Species having very low rates of survivorship early in life.
- Early Loss
- r-selected species tend to exhibit type III curves
Population growth rate
number of offspring an individual can produce in a given time period, minus deaths of individual or its offspring during same period.
Intrinsic growth rate (r)
maximum potential growth of a population under ideal conditions with unlimited resources
What kind of graph is a J-shaped Population Growth Curve?
curve of exponential growth model when graphed.
What kind of graph is a S-shaped Population Growth curve? Describe the kind of growth that these models show.
curve of logistic growth model when graphed, growth model describes a population whose growth is initially exponential, but slows as population approaches carrying capacity of environment.
Corridor
Strips of natural habitat that connect populations.
Metapopulation
group of spatially distinct populations that are connected by occasional movements of individuals between them.
Inbreeding Depression
When individuals with similar genotypes (typically relatives) breed with each other & produce offspring that have an impaired ability to survive & reproduce
Carrying capacity (K)
The limit of how many individuals in a population the environment can sustain.
Overshoot
When a population becomes larger than the environment’s carrying capacity.
Die-off (Dieback)
A rapid decline in a population due to death.
Density-dependent factor
A factor that influences an individual’s probability of survival & reproduction in a manner that depends on the size of the population.
