Modelling natural selection

These practicals focus on particular examples evolution by natural selection, over school year timescales, and will help students to understand the bigger picture.

Experiments

• Selection in action - peppered moths
  Use web-sourced material, maps and population data to explore the industrial melanism of Biston betularia (the peppered moth).
• Selection in action - banded snails
  Use presented data about the frequency of different varieties of snails to make deductions about selection pressure and changing populations.
• Brine date
  Develop practical skills of scientific enquiry in an investigation of living brine shrimps – Artemia salina. Consider evidence that supports Darwin’s ideas about sexual selection.
• A simple model for natural selection
  Pick grains of coloured rice from coloured vermiculite as a model for natural selection. Follow the change in the characteristics of a population over a number of generations.
• A model for natural selection – spaghetti worms
  Investigate natural selection using ‘worms’ made from cooked spaghetti of different colours, observe which ones birds prefer to eat and monitor how ‘populations’ change over time.