Within each species and sub-species exists a unique pool of genetic codes. This pool has enabled plants and animals to adjust to change ie its evolved by natural selection. This diversity is what gives our food its flavour, food value, resistance to disease, adaptability... We are allowing this pool – an invaluable resource - to diminish, cutting what we can draw on to develop plants and animals for food in the face of environmental change. Two very common foods –potatoes and wheat - illustrate the situation well.
The original home of the potato is the Andes, South America. Breeders are continually looking there for new genetic material – but as natural and semi-natural areas are cleared, built on, farmed and so on the range of genetic material is decreasing. Andean farmers have increasingly been encouraged to discard old potato varieties for newer, higher productivity ones. Artificial gene banks of seeds and living material are likely to be no substitute for the real thing! There is enormous value in preserving and growing traditional varieties and in protecting natural areas, preserving genetic material where it has developed.