Populations Flashcards
zanzi and anika
What is a population?
A group of individual organisms of the same species living and interacting in the same area.
What is the primary characteristic of a population?
Interbreeding to produce fertile offspring.
What is the estimation of population size based on?
Based on evidence → sampling
What is a random sample?
A random sample is when every member of a population has an equal chance of being selected for the sample.
What is sampling error?
Sampling error is the difference between the true and estimated value.
How is population size estimated?
Population size is estimated, not counted.
What is the first step in the capture-mark-release-recapture method?
Capture the organisms.
What is the second step in the capture-mark-release-recapture method?
Mark the organisms.
What is the third step in the capture-mark-release-recapture method?
Release the organisms.
What is the fourth step in the capture-mark-release-recapture method?
Recapture the organisms.
What is the fifth step in the capture-mark-release-recapture method?
Calculate the Lincoln index.
What is the formula for the Lincoln index?
Population size: M x N/R
- M: The number of individuals that are captured within a defined area, then marked and released
- N: The number of individuals that are recaptured after sufficient time has passed for reintegration
- R: The number of marked individuals in the recaptured sample
m
What is one assumption of the Lincoln index method?
No migration.
What is another assumption of the Lincoln index method?
No deaths or births.
What is a third assumption of the Lincoln index method?
Marked and unmarked organisms have the same chance of being captured.
What is a fourth assumption of the Lincoln index method?
Marks remain visible.
What is a fifth assumption of the Lincoln index method?
Marks do not affect survival.
What is carrying capacity?
Maximum population size that an environment can support.
What promotes competition among organisms?
Scarce resources promote competition.
What are examples of scarce resources for plants?
Water, light, nutrients.
What are examples of scarce resources for animals?
Water, food, territory, oxygen.
What is negative feedback control in population size?
Populations might rise and fall periodically but are relatively stable over time.
What are the two types of factors that affect population size?
- Density-independent: same effect no matter the population size. 2. Density-dependent: have an increasing effect when the population is bigger.
What is an example of a density-independent factor?
Fire.
What are some examples of density-dependent factors?
- Competition 2. Predation 3. Diseases/parasites
What organisms are used in modelling the sigmoid population growth curve?
Duckweed or yeast
What is the starting condition for modelling sigmoid population growth?
Start with a small number of organisms and abundant resources
What can be investigated in sigmoid population growth modelling?
Carrying capacity or factors that affect growth
What should be considered when using models for population growth?
Strengths and limitations of using models
