Stephen Hawking: "The Human Species Has Entered a New Stage of Evolution"
- The Daily Galaxy Top Story of 2009
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.
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.
Casey Kazan
The INTERNET now has a personality. YOURS! See your Yahoo! Homepage.
http://in.yahoo.com/
