Lecture 6 – When will pigs have wings?
From the 1984 lecture programme:
Many diseases have an inherited component. Some, such as Huntingdon's chorea, or muscular dystrophy, follow simple patterns of inheritance in families, which can now be traced using markers provided by genetic engineering techniques. This offers the possibility of detection very early in pregnancy and so abortion if the foetus is affected.
These approaches to treating genetic disease give rise to difficult moral decisions.
Most of the genetic differences between people are normal, and not connected with disease. They can, for example, be used to trace relationships between different populations.
In much the same way, differences between species measured at the genetic level tell us about their evolutionary relationships. The normal inherited differences must also contribute to all aspects of human variation, including behaviour, facial features, intelligence, musical ability, athletic prowess – the list is endless.
So far these variations have proved too complicated to be sorted out properly at the genetic level. But the new genetics will eventually identify all the human genes and their functions. How far will this take us in explaining the infinite variety of mankind?
About the 1984 CHRISTMAS LECTURES
From the 1984 lecture programme:
We are all different, in looks, in behaviour, and in our susceptibility to disease. Many of these differences are reflected in the chemical makeup of our body and its cells, and most such differences are inherited.
The basic determinants of inheritance, the genes, make up the chromosomes that are found in the nucleus at the centre of every cell. The formal mechanics of inheritance and chromosome behaviour were worked out by Mendel, and later, his successors in the early years of this century. But the chemistry of the genes starts with the DNA double helix of Watson and Crick.
The language of the genes has now been deciphered, so that the small misprint that can cause a major disease, such as the sickle-cell anaemia found mainly in people of African origin, can be read and interpreted.
New developments in genetics have made it possible to study the chemistry of the genes to an extent that could hardly even have been imagined only ten or fifteen years ago. This new genetics, or genetic engineering as it is sometimes called, is beginning to uncover the secrets underlying individual differences, and to provide the tools for understanding and perhaps correcting diseases with a genetic basis.
Now we are beginning to see what it might be that turns a normal cell into a cancer cell, and why the body sometimes attacks itself to produce diseases such as diabetes in children or rheumatoid arthritis.
When will the new genetics tell us why, or whether, one person may become a gifted painter, another a musician, another an athlete and another a mathematician? How far can we go in explaining the infinite variety of mankind?
