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close this bookBiotechnology and the Future of World Agriculture (GRAIN, 1991)
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View the document(introduction...)
View the documentCutting and pasting
View the documentAbout language and limitations
View the documentCulturing cells and tissues
View the documentControlling the process
View the documentA new threshold?

(introduction...)

' Why trouble to make compounds yourself when a bug win do it for you?'
(Biologist J. B. S. Haldane, 1929)'

People have known for thousands of years that there are mechanisms that govern inheritance. Family resemblances could not be merely coincidental. Farmers also realized this long ago, when selecting crops and animals with desired characteristics for further reproduction. But the mechanism of how these characteristics are passed on from generation to generation has been understood only relatively recently. The first important contribution to this understanding was provided by the Austrian monk and botanist Gregor Mendel. From 1857 he spent many hours over several years in the gardens of his monastery, cross-breeding different pea varieties and trying to understand how traits such as colour and height were passed on to subsequent generations. Mendel pointed to 'hereditary factors' present in each of the parents, and was able to show that such factors do not blend when coming together in the offspring, but segregate. Sadly for Mendel, nobody took notice of his work and he died in 1884 without the slightest idea that his findings would, much later, form the very basis of plant and animal breeding and the science of genetics in general.

During the first half of this century many important improvements were made in the use of microbes for industrial production. But it was only in the 1940s that a Canadian doctor, Oswald Avery, established that the 'hereditary factors' Mender had pointed to are located on the DNA (deoxyribonucleic acid). He and his colleagues managed to transfer DNA from one micro-organism to another, thus proving that the hereditary information is stored on it. This laid the basis for answering the questions of the 'why' and 'how' at breathtaking speed. In 1953, Watson and Crick unravelled the three-dimensional structure of DNA, a double helix, each composed of chains of four different chemical bases. Later, it was found that the DNA's bases in groups of three - each called a codon - form a code, and that several of them together - a gene - form the instructions for building a protein. By the mid-1960s the entire genetic code of DNA had been deciphered, and biotechnologists started to experiment with it.