Hawking’s theory of evolution

Although It has taken homo sapiens several million years to evolve from the apes, the useful information in our DNA, has probably changed by only a few million bits. So the rate of biological evolution in humans, Stephen Hawking points out in his Life in the Universe lecture, is about a bit a year.

“By contrast,” Hawking says, “there are about 50,000 new books published in the English language each year, containing of the order of a hundred billion bits of information. Of course, the great majority of this information is garbage, and no use to any form of life. But, even so, the rate at which useful information can be added is millions, if not billions, higher than with DNA.”

This means Hawking says that we have entered a new phase of evolution. “At first, evolution proceeded by natural selection, from random mutations. This Darwinian phase, lasted about three and a half billion years, and produced us, beings who developed language, to exchange information.”

But what distinguishes us from our cave man ancestors is the knowledge that we have accumulated over the last ten thousand years, and particularly, Hawking points out, over the last three hundred.

“I think it is legitimate to take a broader view, and include externally transmitted information, as well as DNA, in the evolution of the human race,” Hawking said.

In the last ten thousand years the human species has been in what Hawking calls, “an external transmission phase,” where the internal record of information, handed down to succeeding generations in DNA, has not changed significantly. “But the external record, in books, and other long lasting forms of storage,” Hawking says, “has grown enormously. Some people would use the term, evolution, only for the internally transmitted genetic material, and would object to it being applied to information handed down externally. But I think that is too narrow a view. We are more than just our genes.”

The time scale for evolution, in the external transmission period, has collapsed to about 50 years, or less.

Stephen-hawking Meanwhile, Hawking observes, our human brains “with which we process this information have evolved only on the Darwinian time scale, of hundreds of thousands of years. This is beginning to cause problems. In the 18th century, there was said to be a man who had read every book written. But nowadays, if you read one book a day, it would take you about 15,000 years to read through the books in a national Library. By which time, many more books would have been written.”

But we are now entering a new phase, of what Hawking calls “self designed evolution,” in which we will be able to change and improve our DNA. “At first,” he continues “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.”

If the human race manages to redesign itself, to reduce or eliminate the risk of self-destruction, we will probably reach out to the stars and colonize other planets. But this will be done, Hawking believes, with intelligent machines based on mechanical and electronic components, rather than macromolecules, which could eventually replace DNA based life, just as DNA may have replaced an earlier form of life.

2 Responses to Hawking’s theory of evolution

  1. Sid says:

    This is probably one of the most interesting articles I’ve read in months. From a functional perspective, there is little difference between whether we biologically evolve wings to help us fly, or use our accumulated knowledge of science to invent planes that enable us to do so. In this context, the human race has been evolving at a terrifying pace for several thousand years (especially in the last 500-1000).

    Also its interesting to think of stored knowledge from a genetics perspective, where bodies of knowledge represent genes, and their modification, combination, and separation, follow a similar pattern as phylogentic/evolutionary trees.

  2. abhijit52 says:

    Hawkings has come up with some more interesting observations about frequency of intelligence in the universe.

    One, since it took evolution about 2.5 billion years to evolve intelligence and the life of the universe is only 13.5 billion years, life has not simply not had the requisite time to evolve into intelligent life in many places.

    Second, considering that even a small asteroid of 20 miles diameter colliding with earth could wipe out all life forms, life even if it evolves runs enormous risk of dying out. Asteroids of this size keep hitting planets every few hundred million years.

    Just last week it has been revealed by an amateur astronomer in Australia that an asteroid has hit Jupiter in last few months resulting in sending up something like the volume of the entire pacific ocean up in Jupiter’s atmosphere. Jupiter is a gaseous planet.

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