THE FARM REVEALED

PROGRAMME 1: SELECTIVE BREEDING AND TRANSGENICS

BACKGROUND INFORMATION

Humans gave up the hunter-gatherer life style about 10,000 years ago, and ever since they have been domesticating and selectively breeding plants and animals. The domestic species that we have today are a legacy of 10,000 years of farming.

All in all, selective breeding is about managing sex. We choose which characteristics we want in our domestic breeds and then we only allow those individuals who show those traits to breed.

Darwin used the term 'natural selection' to show that evolution works in a similar way. In nature, genetic traits are selected by the environment. Organisms that have a knack of surviving and thriving in a particular ecosystem will leave more offspring behind them in that environment than those who are not so well suited to it. This process is described by the catch phrase 'survival of the fittest'. Over many generations of this survival of the fittest, the population of organisms will undergo genetic change in the same way that domestic species do. In nature, species are said to become adapted to their environments.

Modern biotechnology has made it possible to manipulate genes directly. Transgenics is the science of mixing genes. In nature, distinct species do not mate – in other words, they don't mix their genes. The ability to switch genes from one species to another in the laboratory has produced 'golden rice', which contains vitamin A, glow-in-the-dark rabbits, non-squashy tomatoes and GM crops containing pesticides.

There is, of course, a lot of media hype about transgenics. It is interesting to speculate how much of it is an emotional response to something that is 'unnatural', and how much of it is a rationally based fear about the dangers of GM crops.