Classification, biodiversity and conservation

Learning objectives

• Relate classification to evolutionary evidence.
• Distinguish species richness from evenness.
• Evaluate sampling and conservation strategies.

The big idea

Classification uses shared ancestry as well as observable traits; molecular sequence comparisons provide evidence alongside morphology. Biodiversity includes variation in genes, species and ecosystems, so species counts alone describe only one dimension. Richness counts species; evenness describes how similarly individuals are distributed among them.

Representative sampling and diversity indices support comparisons, but methods and sampling effort must match. Conservation can protect habitats and ecological processes or maintain populations outside their original habitat. Decisions should consider genetic diversity, connectivity, threats and long-term monitoring rather than treating release numbers as a complete measure of success.

Investigate and explain

Using the worked example as supplied data, predict the effect of changing one condition. Draw a labelled model, record your reasoning and identify a variable that would need controlling. No human, animal or microbial experiment is required.

No exact PhET model is claimed for this topic. Use diagrams and supplied-data reasoning instead.

Open the interactive investigation

Check your understanding