Aping Biology, Computer Guides Automated Evolution Of A


By KENNETH CHANG - New York Times

August 31, 2000

For the first time, computer scientists have created a robot
that designs and builds other robots, almost entirely
without human help.

In the short run, this advance could lead to a new industry
of inexpensive robots customized for specific tasks. In the
long run -- decades at least -- robots may one day be truly
regarded as "artificial life," able to reproduce and evolve,
building improved versions of themselves.

Such durable, adaptive robots, astronomers have suggested,
could someday be sent into space to explore the galaxy or
search for other life.

But the quest to create artificial life also revives
concerns that computer scientists could eventually create a
robotic species that would supplant biological life,
including humans.

"Some things we probably can do we shouldn't do," said Bill
Joy, chief scientist at Sun Microsystems, who wrote a recent
article warning of the power of emerging technologies. "Just
like we can kill things with DDT, but we shouldn't."

For now, the robotic manufacturing system -- a computer
hooked up to a machine that builds plastic models -- in the
laboratory of Dr. Jordan B. Pollack and Dr. Hod Lipson at
Brandeis University in Waltham, Mass., cannot create
anything nearly as complicated as itself. Instead, it
produces eight-inch-long contraptions of plastic bars and
ball joints.

When a motor and microchip are added, the automatons have
one, and only one, ability: to crawl slowly. The fastest can
scuttle along at a few inches a second.

"They look like toys," Dr. Pollack, a professor of computer
science, said. But, he added, "They were not engineered by
humans, and they were not manufactured by humans."

Dr. Pollack and Dr. Lipson, a research scientist, report
their results in today's issue of the journal Nature.

"This is the first example of pretty much 100 percent
automated evolution of a machine," said Dr. Philip Husbands,
a professor of artificial intelligence at the University of
Sussex in England. "It's a rather primitive example, but
it's the first step to something that could be quite

In the future, the technique could be used to design robots
that assemble parts in factories, clean up chemical spills
or vacuum a home.

Because computers cost much less than human engineers, "It
opens for the first time a more economical approach to
robotics," Dr. Pollack said. "We can now essentially design
for free and build for a few thousand dollars."

The cost of designing a robot today typically runs from
hundreds of thousands of dollars to millions of dollars, Dr.
Pollack said.

The computer in the Brandeis system had no idea what a
successful design might look like. Instead, it was merely
given a list of possible parts it could work with, the
physical laws of gravity and friction, the goal of moving on
a horizontal surface and a group of 200 randomly
constructed, nonworking designs.

Mimicking biological evolution, the computer added,
subtracted and changed pieces in the designs. At the same
time, the computer similarly mutated the programming
instructions for controlling the robot's movements. After
each step, the computer ran simulations to test the designs,
keeping the ones that moved well and discarding the

After 300 to 600 generations of evolution and fine-tuning,
the computer sent the design to a prototyping machine, used
by manufacturers to build test models of product designs, to
build the robot. Then, in the step that required human help,
the researchers installed the robot's motor and microchip
and downloaded the robot's programming instructions.

Changing the initial configuration of the robot parts
produced a different design and a different approach to
locomotion. One pushes itself along. "It's kind of like an
accordion," Dr. Pollack said.

Another one "walks something like a crab," Dr. Lipson said.
"It looks like it's crawling on the floor. It's quite
surprising the diversity of solutions we get."

In earlier work, other researchers used similar
evolution-inspired algorithms to evolve imaginary creatures
that existed only in virtual computer worlds or to design
the programming instructions.

The robots' evolution is currently a dead-end, as the
designing computer never learns how well its designs work in
the real world. The simple robots also have no ability to
improve their performance. According to the researchers, the
robots currently have the brainpower of bacteria. "We hope
to get up to insect level within a couple of years," Dr.
Pollack said. "There's no danger of Commander Data walking
out of our fabricator anytime soon," he said, referring to
the android character in "Star Trek."

In future research, the Brandeis researchers intend to add
sensors to the robots and improve the design programs.

Future robots may also be able to exchange information among
each other and learn from each other's experiences.

As computer chips speed up and fabrication machines become
more sophisticated, the robotic designers will produce
robots that are more and more complex. Some have wondered
what will happen when a robot can design and build something
as complex as itself.

For example, Dr. Seth Shostak, an astronomer at the SETI
Institute in Mountain View, Calif., has suggested that
researchers listening for radio signals from alien
civilizations are more likely to first come across
intelligent machines created by aliens.

In an article in the April issue of Wired, Mr. Joy argued
that scientists should perhaps deliberately steer themselves
away from research that would create self-replicating,
evolving, autonomous robots.

With forethought, he said, computer scientists should be
able to tap into most of the benefits of the emerging
technology while avoiding the dangers.

"This doesn't have enough of the pieces to be by itself
dangerous," Mr. Joy said about the Brandeis work. But, he
added, "We're on the road to somewhere where there's big
issues down the road."

Others working in the field are not as worried, even if
technological advances make such devices possible. Dr. Ralph
C. Merkle of the nanotechnology firm Zyvex and an adviser to
the Foresight Institute, said that high costs would probably
prevent the design of dangerous robots. Rather, robots would
continue to be designed for specific tasks with little or no
ability to evolve and adapt.

"It looks like having a device to work at all is hard," Dr.
Merkle said. "There is no desire to add additional
complexity. Those systems do not look like they would be

The Brandeis researchers find the speculation premature.
"Really, it's so far removed from anything dangerous," Dr.
Lipson said about their work. "There are many other things
to worry about before this."

This file was provided to you by the WordWeaver


End Of File