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Life"s own alphabets

  • 14/12/1995

Life LIFE probably evolved from the primeval soup some 3-4 billion years ago, when the first complex organic polymers were synthesised in the form of a small chain of ribonucleic acid (RNA). Initially the evolution of singlecell organisms like bacteria took; place and then a slow evolution of multicellular organisms occurred.

Steve Jones, a well known evolutionary geneticist, has rightly chosen the title - The Language ofthe Genes. He justifies the title by saying that "Genetics is itself a language, a set of inherited instructions passed on from generation to generation. It has a vocabulary - the genes themselves, a grammar - the way in which the inherited information is arranged, and a literature with thousands of instructions needed to make a human being. The language is based on the dioxyribonucleic acid (DNA) molecule, the famous 1900 double helix, which has become the ico-1 the 20th century.

In every generation there are mistakes in transmission and, in time enough differences accumulate to produce a new language or a new form of life. Further,the language of the genes has simple alphabets not with 26 letters, but consisting of just four. These are the four different DNA bases - adenine, guanine, cytosine and thymine (A,G, C and T). The bases are arranged in words of three letters such as CGA or TCG. Most Of the words are codes for different amino acids, which are joined together to make proteins, the building blocks of the body.

The book deals with the evolution future of genes, particularly human evolution (including agricultural evolution and terns of social development). Jones has explained recent subjects like genetic e neering, DNA fingerprinting and molecular biology with great clarity and precision.

He gives interesting insights into the inheritance of several human character such as the skin colour. The impact of environment and genetics in cont ling the individual differences and the concepts of racism are also cove It also describes the use of various molecular biological techniques the mapping of human DNA, (human genome project), with reference to some of the mos: dreaded genetic diseases and casual mechanisms (for example, mutations) and remedy to these diseases by gene therapy.

Finally, the use of genetic engineering techniques to improve plants and animals to suit the needs of the growing human population, and the possible dangers in releas genetically manipulated creatures described elegantly. The author feel s t most social changes seem to be Cnspirin . slow down human evolution. Mutati selection and random change have all some oftheir effectiveness in the past few centuries. All this means that the biology of the future will not be very different from that of the past. It could be that economic advancement and medical progress will lead to the end ofhuman evolutionary road.

The book is thoroughly lucid and witty. It will be of great interest to any one who wants to know what genetics can tell us about our past, present and even our future.