4.6.6 Random Sampling

Key Concepts

• Interspecific Variation: Differences between species.
• Intraspecific Variation: Differences between individuals of the same species.
• Gene Technology: Modern techniques allow scientists to determine genetic diversity by analysing DNA, mRNA, and amino acid sequences.
  • Differences in DNA base sequences provide the most direct measure of genetic diversity.
  • Amino acid sequences can be traced back to mRNA and DNA sequences.

Sampling Techniques

1. Random Sampling: Ensures that each individual in the population has an equal chance of being selected.

• Tools to Reduce Sampling Bias:
• Quadrats: Used to mark specific areas for sampling.
• Transects: Lines across a habitat used for systematic sampling.
• Randomly generated coordinates can be used to place quadrats or transects.

2. Avoiding Bias and Increasing Reliability:

• Sampling Bias: May occur if certain areas or individuals are unintentionally favoured during data collection.
• Chance: Even with random sampling, the sample might not represent the entire population.
• Larger Sample Size: A larger sample reduces the influence of anomalies and ensures more reliable results.

Advantages of Random Sampling

• Minimises bias.
• Provides representative data when paired with large sample sizes and statistical analysis.