Population Dynamics
Biology: IB Diploma Higher Level, topic 8.1.1
Population Dynamics
Populations are dynamic entities. Populations consist all of the species living within a specific area, and populations fluctuate based on a number of factors.
Factors affecting populations
- A population consists of individuals of the same species living within a specific area.
- Populations fluctuate based on both biotic and abiotic factors.
- These can include seasonal and yearly changes in the environment, natural disasters such as forest fires and volcanic eruptions, and competition for resources between and within species.
Population size and density
- The study of any population usually begins by determining how many individuals of a particular species exist, and how closely associated they are with each other.
- Within a particular habitat, a population can be characterized by:
- Its population size (N), the total number of individuals,
- Its population density, the number of individuals within a specific area or volume.
Demography
- While population size and density describe a population at one particular point in time, scientists must use demography to study the changing dynamics of a population.
- This statistical study of these changes, demography, investigates how populations respond to these fluctuations.
- A shift in populations can affect community structure and the ecosystem as a whole.
- Demography involves the statistical use ofmetrics like birth rates, death rates, and life expectancies.
Test yourself on Population Dynamics
In population studies, what is the letter "N" used to represent?