Lecture 2 - Studying ecology/populations Flashcards
Name the stages of Hypothetico deductive reasoning (the scientific method)
- Observation
- General hypothesis
- Specific hypothesis
- Test
Why do ecologists take samples and what do they do once they have taken the sample?
They take samples as often populations are too large for you to record every single individual organism within it. Once they have taken the sample they analyse it and extrapolate the data in order to gain an estimation of the total number of organisms within the population.
What is a confounding factor?
A factor which may affect the population that you are measuring however isn’t the actual factor which you are studying.
Name a stat technique used to quantify error.
Standard deviation.
What is population dynamics?
The patterns and processes of population change over space and time.
Density
The number of individuals per unit area.
Dispersal
Immigration and emigration of individuals.
Dispersion
Spatial distribution patterns.
Name the 3 main factors which affect population size.
- Biological interactions.
- Physical environment
- Dispersal
Name a study in which the population was small enough that every individual could be measured.
760 elephants in national reserves in Kenya were recorded based on their ear markings.
How are sessile organism numbers recorded?
Quadrats and transects are used to measure abundance of sessile organisms.
How are motile organism numbers estimated?
The mark-release-recapture method is used to track numbers of motile organisms.
What is eDNA used for and from what sources can it be taken?
eDNA is used to see how many unique individuals there are within a population and this DNA can be derived from fur, feathers and faeces.
Abundance
The total number of individuals, or total percentage cover, within a sample
Species richness
The number of taxonomic groups within a sample.
