Duration and Setting
30 — 60 minutes in the classroom.

Summary
In this activity students learn about the diversity of plant and animal species involved in global food production and the importance of having genetic diversity within a species.

Student outcomes
This activity will enable students to:

• Discover the relatively small number of plant and animal species that provide food for humans across the world
• Discuss the importance of genetic diversity within a species in adapting to changing climatic conditions and consumer demands on food production
• Understand the implications of low genetic and species diversity for food production.

Background notes for teachers
Did you know that only twelve plant species and six animal species provide more than 70% of all human food? Or that just four plant species (potatoes, rice, maize/corn and wheat) and three animal species (cattle, pigs and chickens) provide more than half of all human food? When teaching and learning about biodiversity (variety of living organisms) we generally think about native plants and animals, however we often don't consider the diversity of the food that we eat.

Agricultural biodiversity provides us with food, clothes and medicines and is essential for sustainable agriculture and food security. In spite of its vital importance for human survival, agricultural biodiversity is being lost at an increasing rate. It is estimated that some ten thousand species have been used for human food and agriculture over time. Currently no more than 120 cultivated species provide 90% of human food supplied by plants. In addition, loss of genetic diversity has occurred for different types of plant and animal species. Hundreds of thousands of varieties that were cultivated in the past have been replaced by a small number of modern and highly uniform commercial varieties. The risk this poses is the loss of agricultural biological diversity that may reduce the capability of present and future generations to face unpredictable environmental changes and human needs (Food and Agriculture Organization of the United Nations).

There is positive news however, as stores of different varieties of seed are maintained around the world, conserving genetic variety and enabling scientists to use these genetic 'pools' to trial development of new varieties of crops that are resistant to drought, temperature variation, reduced water availability, salt, disease or other factors impacting on agricultural production.

This activity introduces students to the top twelve agricultural crops and six livestock species produced across the world (measured in million metric tons), and encourages students to investigate and consider the importance of diversity in the food that is available for them to eat.

next» Biodiversity on a Plate—Part 2