| Santa
Fe New Mexican |
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Geoffrey
West takes fresh look at basic biology
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| By JEFF
TOLLEFSON/The New Mexican |
November
19, 2001 |
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Geoffrey
West once spent his time breaking things down into universal
building blocks. Atoms. Electrons. Quarks. Strings.
Like most physicists, he considered these particles and their
behavior in a kind of scientifically imposed isolation from the rest
of the world. He finds this kind of work interesting, even necessary,
but somehow incomplete. |
The
British-born researcher has 26 years with Los Alamos National
Laboratory under his belt, but over the years his interest has
migrated from individual particles to complex organisms and
ecosystems.
Enter the Santa Fe Institute, a scientific think tank that supports
research in chaos and complexity theory. Tapping into the Santa
Fe-based Thaw Charitable Trust, as well as government grants, West
joined several scientists from different disciplines at the
institute and pioneered a new approach to biology. That was about
five years ago.
"We believe we have discovered some universal principles that
apply across the great diversity of life."
That was West earlier this month, describing his work as he prepared
for a series of public lectures sponsored by the Santa Fe Institute.
He spent three evenings explaining the theory behind a set of
remarkably simple algebraic equations that he and his colleagues
have used to predict everything from how big organisms grow and how
fast their hearts beat to how long they tend to live.
His work and that of others, including James Brown of The University
of New Mexico and Brian Enquist of the University of Arizona, has
been published in a series of peer-reviewed papers in the journals
Nature and Science during the last several years. Recent articles
have raised eyebrows in the scientific community, drawing enormous
praise and skepticism.
Cornell University botanist Karl Niklas has said that the underlying
theory could be as significant to the field of biology as Sir Isaac
Newton's contributions were to physics. If the theory holds true,
Niklas said in the Sept. 27 edition of Nature, it has "the
potential to explain virtually everything."
West, 60, laughs when he hears such praise.
"Well, that's crazy. But it's marvelous," West said
Tuesday at the
Santa Fe Institute. His corner office overlooks the town and the
Jemez Mountains, where Los Alamos National Laboratory is visible on
a clear day.
West said his work has him looking at the world in a new way. The
Londoner earned his doctorate in physics at Stanford University -
mostly an excuse to spend a year in California, he said.
He was enticed to Santa Fe by the lab in 1976 and never left.
Several years ago he became serious about an old hobby: Thinking
scientifically about the world around him.
"I realized that my whole career has been spent on abstractions,"
he says. "And of course I love abstractions, but there was
something wonderful about being able to relate the abstractions to
the stuff you touch and feel around you, the exquisite beauty of
nature."
Fractals
West began looking at that world through the lens of fractals. Think
of the Grand Canyon; any arroyo outside of town is really a
scaled-down version of the same thing.
Take a black-and-white photograph of both, without any references to
scale, and the pictures would seem remarkably similar. This is why
some detailed photographs include a distinguishable feature - a coin,
knife or a hand - to help the viewer determine size.
Now think of your own cardiovascular system, which distributes
energy equally and efficiently to the almost countless individual
cells that collectively give you life.
Picture the large arteries leading from the heart and gradually
branching out into capillaries that carry blood to individual cells
throughout the body.
Compare that to a cottonwood tree, with its thick trunk gradually
giving way to smaller and smaller limbs. The concept is much the
same: It's a branching network that trees use to ensure proper
distribution of energy.
West's research focuses on the similarities among these and other
biological systems, from single-celled organisms to mammals, plants
and ecosystems. Rather than studying the circulatory system of a
horse, for instance, this approach scans all circulatory systems in
an effort to discern and distill a simple truth.
The basic concept, known as scaling, posits that all life is
governed by the same framework of physical laws. These laws
constrain biological development, both allowing for and limiting
growth.
And according to West and his colleagues, the rules that govern
bushes and trees and mice and elephants are the same. The same
algebraic equations that predict the size and heart rate of a cat
also work for a rhinoceros. The larger organism, using this logic,
is a scaled-up version of its smaller counterpart.
"And it works. That is the most amazing thing," West says.
"In some ways, the biggest mystery of this work is, 'Why does
it work so well?' "
What does this mean for you? For one thing, West explained to a
packed house during the Santa Fe Institute's recent lecture series,
the idea that people will continue to live longer and longer lives
is probably a pipe dream. Biologically speaking, he said, all
organisms are programmed to live and die, and the rate at which they
do so is the same.
"A little mouse may only live two or three years, and a whale
may live roughly 60, but they have the same number of heart beats.
And that is roughly a billion. It's as if an organism of a given
size has its own internal clock ticking away."
West presented a formula that takes into account energy consumption,
cellular growth and size of an organism to determine age. Graphing
the results compared to age actual statistics, he presented a
straight line from shrews to whales; humans figure in at about 40
years, which was about right before modern advances in cleanliness
and medicine.
The trick to understanding scaling, West says, is knowing that
everything does not scale equally according to size. Ants can carry
many times their body weight. Horses can't. Birds eat more than
their body weight each day. Elephants don't.
Since all animals are similar at the cellular level, that means the
metabolism in larger animals is more efficient: Each cell is burning
less energy. West says this is evolution at work. Furthermore, he
notes that this shift in energy efficiency is governed by the same
rules that govern size, heart rate and longevity. That means it can
be predicted by similar algebraic equations.
In essence, he says, the biological system in larger animals somehow
imposes efficiency gains on individual cells. Following this
approach, scientists need to look at the whole system, because
adding up the individual parts in a laboratory can produce "the
wrong answer."
West says his work takes place where physics and biology interface.
Physics is a science that is forever in search of, and bound by,
fundamental rules. To date, he explained to his audience, biology
has been geared more towards describing and understanding individual
organisms.
This new approach uses mathematics, which West calls "the
language of the universe," to describe fundamental principals
that apply to everything "from microbes to elephants."
Such an approach turns biology into a concrete science with the
power to predict, West says.
"The basic message is that there are fundamental principals
that unite all of life," he says with a chuckle, noting that it
can be difficult to avoid clichés when describing such work. "It's
very much this idea of seeing things, the interconnectedness of all
life." |
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