C4.1.1 – Populations as Interacting Groups of Organisms of the Same Species Living in an Area

Define Population

• A group of individuals of the same species living in a particular area at the same time, capable of interbreeding and interacting.

What Isolates Populations of the Same Species?

• Geographical barriers: Mountains, rivers, oceans.
• Behavioral differences: Mating behaviors or social structures.
• Temporal isolation: Different breeding or feeding times.
• Physical barriers: Fragmentation of habitats due to human activity.

C4.1.2 – Estimation of Population Size by Random Sampling

Define Sample

• A subset of the population used to make inferences about the entire population.

Purposes of Sampling a Population

1. Estimate population size in large or inaccessible areas.
2. Track changes over time (e.g., species abundance).
3. Identify patterns in distribution or density.

Define Sampling Error

• The difference between population estimates derived from a sample and the true population value.

Need for Randomness in Sampling

• Ensures that the sample is representative of the population.