Unit 3: Populations Flashcards
(73 cards)
Survivorship curves
It show age-distribution characteristics of species, reproductive strategies, and life history
Reproductive success
It is measured by how many organisms are able to mature and reproduce, with each survivorship curve representing a balance between natural resource limitations and interspecific and intraspecific competition
Carrying capacity (K)
It refers to the number of individuals that can be supported sustainably in a given area
Population dispersal pattern
It is how individuals or species of animal become distributed in different spaces over certain periods of time
Clumped
Some areas within a habitat are dense with organisms, while other areas contain few members
Random
Occurs in habitats where environmental conditions and resources are consistent
Uniform
Space is maximized between individuals to minimize competition
Biotic potential
The maximum reproductive capacity of an organism under optimum environmental conditions
Environmental Resistance
Any factor that inhibits an increase in the number of organisms in the population
J-Curve
It represents a population growth occurs in a new environment when the population density of an organism increases rapidly in an exponential or logarithmic form, but then stops abruptly as environmental resistance or another factor suddenly impacts the population growth
S-Curve
It occurs when, in a new environment, the population density of an organism initially increases slowly but then stabilizes due to the finite amount of resources available
Limiting Factor
It can be any resource or environmental condition that limits the abundance, distribution, and/or growth of a population
Density-dependent limiting factors
These are factors whose effects on the size or growth of the population vary with the density of the population
Density-independent factors
These are factors that limit the size of a population, and their effects are not dependent on the number of individuals in the population
Rule of 70
It helps to explain the time periods involved in exponential population growth occurring at a constant rate
Doubling time
It is the amount of time it takes for a population to double in size
Age-structure diagrams
These are determined by birth rate, generation time, death rate, and sex ratios
Pyramid-shaped age-structure diagram
It indicates that the population has high birth rates and the majority of the population is in the reproductive age group
Bell shape age-structure diagram
It indicates that pre-reproductive and reproductive age groups are more nearly equal, with the post-reproductive group being smallest due to mortality
Urn-Shaped age-structure diagram
It indicates that the post-reproductive group is largest and the pre-reproductive group is smallest, a result of the birth rates falling below the death rate, and is characteristic of declining populations
Total fertility rate (TFR)
The average number of children that each woman will have during her lifetime
Earth Wisdom
Natural cycles that can serve as a model for human behavior
Frontier Worldview
Viewed undeveloped land as a hostile wilderness to be cleared and planted, then exploited for its resources as quickly as possible
Planetary Management
Beliefs that as the planets most important species, we are in charge of Earth