Friday, December 7, 2007

Mutations - IOT

After the recording of In Our Time, host Melvyn Bragg puts out a newsletter. About the latest issue he sums things up very well.


Well, it’s often said that appearing on radio or television, in films or on the stage, or anywhere in public, is a transforming experience but I didn’t think that just sitting down would be as transforming as today’s contributors made clear. Millions of mutations are taking place as I dictate this newsletter. It makes me feel quite uneasy. So silent, so effective, so deleterious (?) mutating away there in the dark inside and me knowing very little about it and being able to do next to
nothing about it.

One of the most revealing statements – there were so many – was the discovery that despite the atomic blasting of Hiroshima and Nagasaki, the genes refused to budge and changes took place in the usual old random way. Similarly, in Morgan’s laboratory in America, after two years of fast breeding the fruit fly and forcing them to change nothing had happened, until a completely random mutation gave a fruit fly white eyes instead of red. As you may have heard, when they caught the fruit fly this began them on a passage of research which became the pattern for the fast-forward of genetics in the 20th century and into the 21st century. Steve Jones emphasised it’s a very young and very new science.

I believe that we might have got through the programme without mentioning Darwin (I haven’t heard it back yet). If so, with Steve as a contributor, this would be the first time in his life he hasn’t mentioned Darwin in public when talking about – well, just about anything.


I thought it might be useful to you to have this glossary which I found very useful indeed:

Mutation: Any discontinuous change in the genetic constitution of an organism. Mutations can occur in DNA or in chromosome structure. Mutation is the ultimate source of all genetic variation.

DNA or deoxyribonucleic acid: The nucleic acid which occurs in combination with protein in the chromosomes, and which contains the genetic instructions for the organism that houses it.

The Gene: A unit of heredity; a segment of the DNA which contains the instructions for the development of a particular inherited characteristic.

Chromosomes: The threads within the nucleus of a cell that become visible during cell division. Chromosomes are the major carriers of genetic material, consisting of DNA and various types of protein.

The Genome: The complete genetic information about an organism. In most organisms this is contained in the DNA sequences within chromosomes.

Gene Pool: The total of all genes in a population of a particular species.

All the best

Melvyn Bragg