Self-Designed Evolution

A lecture given by Stephen Hawking and reprinted in Scientific American has been gathering a lot of attention recently in cyberspace.

Here are some excerpts from the full transcript:

Life in the Universe

I would like to speculate a little on the development of life in the universe and, in particular, the development of intelligent life. I shall take this to include the human race, even though much of its behaviour throughout history, has been pretty stupid and not calculated to aid the survival of the species. Two questions I shall discuss are, ‘What is the probability of life existing else where in the universe?’ and, ‘How may life develop in the future?’

It is a matter of common experience that things get more disordered and chaotic with time. This observation can be elevated to the status of a law, the so-called Second Law of Thermodynamics. This says that the total amount of disorder, or entropy, in the universe always increases with time. However, the Law refers only to the total amount of disorder. The order in one body can increase, provided that the amount of disorder in its surroundings increases by a greater amount. This is what happens in a living being. One can define Life to be an ordered system that can sustain itself against the tendency to disorder, and can reproduce itself. That is, it can make similar, but independent, ordered systems. To do these things, the system must convert energy in some ordered form, like food, sunlight, or electric power, into disordered energy, in the form of heat. In this way, the system can satisfy the requirement that the total amount of disorder increases, while, at the same time, increasing the order in itself and its offspring.

A living being usually has two elements: a set of instructions that tell the system how to sustain and reproduce itself, and a mechanism to carry out the instructions. In biology, these two parts are called genes and metabolism. But it is worth emphasizing that there need be nothing biological about them. For example, a computer virus is a program that will make copies of itself in the memory of a computer, and will transfer itself to other computers. Thus it fits the definition of a living system that I have given. Like a biological virus, it is a rather degenerate form, because it contains only instructions or genes and doesn’t have any metabolism of its own. Instead, it reprograms the metabolism of the host computer, or cell. Some people have questioned whether viruses should count as life, because they are parasites and cannot exist independently of their hosts. But then most forms of life, ourselves included, are parasites in that they feed off and depend for their survival on other forms of life. I think computer viruses should count as life. Maybe it says something about human nature that the only form of life we have created so far is purely destructive. Talk about creating life in our own image. . .

There is no time to wait for Darwinian evolution to make us more intelligent and better natured. But we are now entering a new phase of what might be called self-designed evolution, in which we will be able to change and improve our DNA. There is a project now on to map the entire sequence of human DNA. It will cost a few billion dollars but that is chicken feed for a project of this importance. Once we have read the book of life, we will start writing in corrections. At first, these changes will be confined to the repair of genetic defects like cystic fibrosis and muscular dystrophy. These are controlled by single genes, and so are fairly easy to identify and correct. Other qualities, such as intelligence, are probably controlled by a large number of genes. It will be much more difficult to find them and work out the relations between them. Nevertheless, I am sure that during the next century people will discover how to modify both intelligence and instincts like aggression.

Laws will be passed against genetic engineering with humans. But some people won’t be able to resist the temptation to improve human characteristics such as size of memory, resistance to disease, and length of life. Once such super humans appear, there are going to be major political problems with the unimproved humans, who won’t be able to compete. Presumably, they will die out or become unimportant. Instead, there will be a race of self-designing beings who are improving themselves at an ever-increasing rate. . .

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