EDGE 8 — March 4, 1997
THE THIRD CULTURE
"COMPLEXITY AND CATASTROPHE"
A Talk with John Maddox
"My guess is that if the question of human extinction is ever
posed clearly, people will say that it's all very well to say
we've been a part of nature up to now, but at that turning point
in the human race's history, it is surely essential that we do
something about it; that we fix the genome, to get rid of the
disease that's causing the instability, if necessary we clone
people known to be free from the risk, because that's the only
way in which we can keep the human race alive. A still, small
voice may at that stage ask, but what right does the human race
have to claim precedence for itself. To which my guess is the
full-throated answer would be, sorry, the human race has taken
a decision, and that decision is to survive. And, if you like,
the hell with the rest of the ecosystem."
THE REALITY CLUB
Ian Stewart on Reuben Hersh
I was told that when Jung invented the idea of the collective
subconscious, a quirk of the German language left it ambiguous
whether he meant a single pool of knowledge into which all humans
dip, or a collections of separate — but very similar —
pools. When we use a single word 'mathematics' we seem to be thinking
of a single collective pool — but, like all human knowledge
and thought, it is really a collection of separate pools.
Daniel Goleman on Joseph LeDoux
All this means that to model the mind in a significant way,
you need the cyber equivalent of an amygdala. All else is a shallow
version of the mind at work.
Steven Pinker on Joseph LeDoux
Put these bits of evidence together and one begins to consider
a developmental theory opposite to the stimulus-response-linkage
account — kids don't start off fearless and gradually acquire
fears through conditioning; they start out fearful (not necessarily
at birth, but in the first few years) and gradually master them,
with adult phobias being childhood fears that never went away.
Joesph Ledoux Responds to Daniel Goleman, Douglas Rushkoff,
William Calvin, Paolo Pignatelli, and Steven Pinker
Coming Events
Jared Diamond, Murray Gell-Mann, J. Doyne Farmer, Stewart Kauffman,
Seth Lloyd, Lee Smolin, and Charles Simonyi
(10,359 words)
THE REALITY CLUB
Ian Stewart on Reuben Hersh
From: Ian Stewart
Submitted: 2/28/97
Re: Reuben Hersh
One point that did occur to me concerns the argument that because
there were nine planets around before humans came on the scene,
that means that the number 'nine' in effect existed already.
I don't agree. The problem is that the universe has no concept
of 'planet', and in a sense would not know what to count. It is
humans who classify the billions of objects floating around in
the solar system according to size and shape, and decide that
some are planets and others not. Without this classificatory step,
there is nothing to count. In short, until something selects a
set of things, there is no preexisting concept of number.
This is not to say that I agree with Reuben that maths is purely
some kind of human activity. (I'm not sure that's what he meant
anyway.) I imagine, for instance, that other intelligent beings
— if they exist, which I think likely — could develop
a similar kind of system. However, I don't see why it has to be
similar to ours, except in 'style'. For instance, aliens that
take the physical form of plasma vortices in the atmosphere of
a star might know far more magnetohydrodynamics than we do, but
have no concept of 'triangle'. I think their maths would be in
the same philosophical area as ours, but might not mesh terribly
consistently.
I was told that when Jung invented the idea of the collective
subconscious, a quirk of the German language left it ambiguous
whether he meant a single pool of knowledge into which all humans
dip, or a collections of separate — but very similar —
pools. When we use a single word 'mathematics' we seem to be thinking
of a single collective pool — but, like all human knowledge
and thought, it is really a collection of separate pools. Because
maths is very precisely determined, the education system can ensure
that all those pools overlap in a very consistent manner, giving
the illusion of a shared common pool. I think this is the sense
in which maths is basically contained in human minds. BUT there
is a more abstract sense in which it is the common pool —
leading a virtual existence but feeling just as real to each of
us as we dip into our part of it as a physical experience does
— and that's a more interesting kind of existence. It's why
many mathematicians think platonistically. Medicine, say —
and definitely music — is not as tightly constrained o be
consistent, so is NOT really the same kind of thing.
IAN STEWART is the 1995 recipient of the Royal Society's
Michael Faraday medal for outstanding contributions to the public
understanding of science. He is author of Does God Play Dice?,
The Problems of Mathematics, Another Fine Math You've Got Me Into,
and Nature's Numbers. He writes the "Mathematical Recreations"
column of Scientific American and is mathematics consultant
to New Scientist and to Encyclopedia Britannica.
He has written articles for such magazines as Discover, New
Scientist and The Sciences. He lives in LondonDaniel
Goleman on Joseph LeDoux
Daniel Goleman and Steven Pinker on Joseph LeDoux
From: Daniel Goleman
Submitted: 2/26/97
Re: Joseph Ledoux
AI: A WAKE UP CALL FROM THE AMYGDALA
LeDoux's groundbreaking work has, understandably, been embraced
by neuroscientists, even psychoanalysts, as the best insight so
far into the workings of the emotional brain and the role of unconscious
processing of emotions in mental life. But the field that should
be standing up and paying attention is artificial intelligence.
LeDoux has shown the neural circuitry that accounts for the fact—established
in separate research by cognitive/social psychology—that
the act of cognition entails emotion. That is, as we comprehend
that this or that is an 'X', we already have an opinion about—as
we realize what it is, we like it or we don't. And this affective
processing occurs in the very first phase of the act of cognition—we
actually have the emotional reaction many milliseconds before
we know exactly what it is we're reacting to.
Couple this intrinsic role of feeling in cognition with Antonio
Damasio's work, showing that sound decision-making and information-processing
in life depends on intact circuitry to the amygdala, and the conclusion
is that need to know our feelings about our thoughts, or we have
no preferences. The only realm where feelings don't matter is
the purely abstract and cognitive—mathematics, for example,
But only mathematics for technicians—not for theoretical
work or creative insight: we're back to the need for feelings—for
intuition, for the "feel" of what's "right".
All this means that to model the mind in a significant way,
you need the cyber equivalent of an amygdala. All else is a shallow
version of the mind at work.
Dan Goleman
DANIEL GOLEMAN is a psychologist and award-winning writer
who covers the behavioral and brain sciences for The New York
Times, and is the author of numerous books including Vital
Lies, Simple Truths, The Meditative Mind, the international
bestseller Emotional Intelligence, and coauthor of The
Consumer's Guide to Psychotherapy. He has taught at Harvard
University and was previously senior editor of Psychology Today.
From: Steven Pinker
Submitted: 2/28/97
Re: Joseph Ledoux
I like Joseph Ledoux's approach, in which he studies a single
system at many levels of analysis, from psychology to molecules.
Decades ago, Tinbergen suggested that anything in psychology has
to be understood at four levels — mechanism, development,
function, and phylogeny. Ledoux's intensive analysis of one psychological
faculty may present a special opportunity to realize Tinbergen's
ideal. I'd like to throw out a couple of questions that speak
to the integration of the four levels; they come from my own approach
to fear in How the Mind Works.
1. LeDoux says, "We aren't born with phobia. Somehow they are
acquired through experience and stored in the brain as links between
stimuli (like snakes or heights) and fear responses." It's true
that we aren't born with phobias, but it doesn't follow that we
necessarily acquire them, or that if we do, that it's by forming
links between stimuli and responses, as "Little Albert" allegedly
did in Watson's experiment. The alternative is that fearful responses
emerge as a product of the postnatal maturation of the brain.
A number of psychologists, anthropologists, and ethologists have
presented evidence for this possibility (Seligman, Rachman, Marks,
Nesse, and others).
First, children spontaneously become fearful of a standard list
of stimuli in the preschool years (strangers, separation, loud
noises, spiders, deep water, the dark, carnivorous animals, etc.).
Second, according to cross-cultural surveys, most typical phobic
objects (such as snakes) are feared in all cultures — and
it is often the cultures that have the *least* exposure to the
objects that fear them the most (e.g., snake phobia in American
cities). Third, many phobics have had no encounters with the object
of the phobia. Fourth, fear responses to objects such as snakes
appear in several laboratory-raised primates — D. O. Hebb
reported that his Yerkes chimps freaked out the first time they
saw a snake, and Marc Hauser tells me his tamarins gave alarm
calls to a piece of rubber tubing on the floor! Even primates
that seem to acquire a fear of snakes, such as rhesus macacques,
acquire it by observing others, not by Pavlovian conditioning,
and acquire it only for standard scary things like snakes, not,
say, for rabbits.
Put these bits of evidence together and one begins to consider
a developmental theory opposite to the stimulus-response-linkage
account — kids don't start off fearless and gradually acquire
fears through conditioning; they start out fearful (not necessarily
at birth, but in the first few years) and gradually master them,
with adult phobias being childhood fears that never went away.
It strikes me that this theory fits the rest of LeDoux's account
fairly well. I wonder whether he has a preference for one of the
two developmental theories, and what the evidence is on the prenatal
and postnatal maturation of the amygdala and its connections to
the rest of the brain, in monkeys and in humans.
2. Ledoux mentions that "the amygdala projects back to the neo-cortex
in a much stronger sense than the neo-cortex projects to the amygdala.
The implication is that the ability of the amygdala to control
the cortex is greater than the ability of the cortex to control
the amygdala. And this may explain why it's so hard for us to
will away anxiety; emotions, once they're set into play, are very
difficult to turn off." Well, it explains it at a mechanistic
or proximate level, though it doesn't explain it a an ultimate
or functional level, since it raises the question of *why* the
connections evolved to be so asymmetrical, at least in humans
(assuming the primate asymmetry were conserved in our evolution).
I've suggested an ultimate or functional explanation — that
a lack of cognitive control of the emotions can be an asset in
strategic conflict between partial adversaries (in the case of
fear, between conspecific threateners and targets), because they
make threats and promises (including a "promise" of surrender
in an aggressive encounter) more credible.
Of course, there are alternative explanations — conceivably
there's some kind of evolutionary inertia or developmental constraint
making it impossible to grow symmetrical connections between amygdala
and cortex. It strikes me that Ledoux's project offers the promise
of allowing us to decide between the accounts someday. Perhaps
one could look at the development of the connections, and see
if the growth factors (or other molecular guides) and the genes
controlling them are the kinds of things that can easily be modulated
in development, with different parts of the brain, or the brains
of different species or even different individuals, showing fine-tuned
control of the degree of symmetry or asymmetry of that kind of
connection. We know that fearfulness shows variation across life
stages, species, breeds (e.g., of dogs), and individuals; perhaps
one could compare the size of their amygdalas or the strength
or asymmetry of their connections to the rest of the brain. One
could even selectively breed animals for different kinds of fear
response and look at their brains. If there was fine-tuned, systematic
variation in the neuroanatomy across these comparisons, it would
suggest that there is no inviolable neurodevelopmental constraint
but that natural selection had considerable freedom in selecting
the genes that wire up animals' brains, presumably in the service
of the survival demands of their niche and social system.-
Steven Pinker
STEVEN PINKER is professor in the Department of Brain and Cognitive
Sciences at MIT; director of the McDonnell-Pew Center for Cognitive
Neuroscience at MIT; author of Language Learnability and Language
Development, Learnability and Cognition, The Language Instinct,
and the forthcoming How the Mind Works (Norton).
Joesph Ledoux Responds to Daniel Goleman, Douglas Rushkoff, William
Calvin, Paolo Pignatelli, and Steven Pinker
From: Joseph Ledoux
Submitted: 3/3/1997
Response to: Daniel Goleman, Douglas Rushkoff, William Calvin,
Paolo Pignatelli, and Steven Pinker
Computation and Emotion
There are lots of good reasons why cognitive science ignored
emotion at the beginning. Emotion just wasn't what this approach
was about. When cognitive science started claiming to be the new
science of the mind, instead of a science of cognition, though,
emotion and related topics should no longer have been ignored.
But they were, and, for the most part, still are. As Dan Goleman
points out, this leads to a shallow view of how the mind works.
To be fair, though, many of the leading researchers in AI and
cognitive science have from time to time recognized this. The
problem is that this recognition hasn't led the rank and file
of cognitive science to embrace emotions with open arms. For the
most part, emotion is still one of those messy things you need
to control in a good cognitive experiment, rather than something
you should study.
It's worth noting, though, that there's a growing interest in
emotions in AI. There is, however, some work in AI that has tried
to bridge the cognition- emotion gap. For example, there are models
of emotional face perception and emotional language recognition,
and an expert system that simulates stimulus evaluation processes.
Also, there's an internet "Cognition-Affect Group" that functions
as a clearinghouse for announcing and describing new findings
or just plain asking questions of people who have an interest
in the subject. Good starts, but more is needed.
My own efforts in this area have involved the development of
a connectionist model of the fear conditioning network. Rather
than starting with a psychological theory of emotion (a tough
task to accomplish) I start with an understanding of the neural
system that underlies one kind of emotion - fear (as modeled by
fear conditioning). This work, but the way, is done in collaboration
with connectionist modelers. The model is anatomically constrained.
These constraints allow the model to discover many aspects of
the behavior and physiology of fear conditioning that we've identified
through animal studies. The model has even made novel, non-intuitive
predictions about the effects of brain lesions. We've then gone
back and tested the predictions in the rat, and the model was
right.
Another point about the model is that it is modular. This means
that we can pick one structure, like the amygdala, and fill it
with simulated neurons that have real physiological and biochemical
properties, while leaving the rest of the model to function at
the systems level (linked structures with generic neuron-like
unit). These kinds of hybrid models that include both neural network
and detailed neuronal compartmental components are potentially
very powerful. The modular nature of the model means that we can
also take other brain regions that have been simulated with some
success, like the hippocampus or areas of neocortex, and integrate
those with our model. We're doing this to try to understand how
cognitive functions such as attention and contextual processing
influence and are influenced by fear arousal.
Have we explained all of emotion through animal studies?
Douglas Rushkoff has the feeling that my ideas about emotion
might work for survival mechanisms like fear, but not for other
more complex emotions. I would be the first to admit this. One
of my main points is that we need to study each emotion on its
own terms, and I make no claim that I've got anything to say about
emotion in general. I'm happy if I can contribute something to
our understanding of fear. Fear is, after all, the emotion that
most often goes wrong and accounts for most so-called emotional
disorders. Remember, Freud's whole theory was based on anxiety.
Memory and Stress
Hippocampal functions (including explicit, declarative memory)
can be impaired by high levels of steroid hormones (stress hormones)
floating around in the blood. This is a well-documented finding
supported by studies of hippocampal physiology in animals and
by studies of hippocampal-dependent memory in stressed animals
and in humans with high levels of steroids (such as in Cushing's
disease and in people with severe depression). These facts are
documented in The Emotional Brain (http://www.cns.nyu.edu/home/ledoux/book.html).
William Calvin calls this a teaching example. He's of course
right when he says that there's no way to know whether a stress-induced
impairment in hippocampal function might account for "false memories"
in traumatized people. I didn't mean to imply that stress effects
on hippocampus could account for false memories. I only meant
that this phenomenon might help explain why there is sometimes
an amnesia for traumatic experiences. False memory is something
else that comes later to fill in the gaps left by the amnesia.
This brings us to Paolo Pignatelli's question about why the
amygdala can't make up for the hippocampal impairment in cases
of stress-induced amnesia. I argued that in stressful situations
the amygdala and hippocampus each form their own memories. The
amygdala forms unconscious emotional memories, and the hippocampus
conscious memories about emotional situations. The amygdala memories
lead to bodily responses, while the hippocampal memories just
lead to thoughts. When the hippocampus is "shut down" by stress
the amygdala continues to form its unconscious memories, and may
form even stronger ones.
Pignatelli asks, why can't the hippocampus later get the information
from the amygdala, converting the amygdala's unconscious memory
into a conscious one? Actually, he's not the first to want to
know this. Many proponents of "recovered memory" have tried to
make this case. Pignatelli comes at it from a perfectly good theoretical
position. If the amygdala and hippocampus are both computing machines,
by which he means Universal Turing Machines, then shouldn't there
be a way for one to read the output of the other?
I think Pignatelli has raised an interesting point. I don't
really know enough about the theory of computation to say whether
the amygdala and hippocampus, or any other two brain regions,
satisfy the requirements of Universal Turing Machines. However,
it seems to me that they are best thought of as special purpose
rather than universal computers. I don't know of any evidence
that would support the idea that the memories of these two systems
are shared, but there is some evidence that they are not. The
evidence comes from a study Jeff Muller did in my lab last year.
The study wasn't done with Pignatelli's question in mind, so it
doesn't completely answer his question, but it goes pretty far.
We temporarily put the amygdala to sleep in rats. This is done
by injecting a drug directly into the amygdala that shuts down
neural activity, but only for a short while. While the amygdala
was out, the rats, which were otherwise fully awake, underwent
a standard fear conditioning procedure. The next day, after the
drug wore off, we tested the rats. They showed no sign of having
learned. Presumably the hippocampus was awake and storing information.
But the amygdala couldn't later use that information to express
learned fear responses. We know that the amygdala injection didn't
affect the hippocampus since even permanent amygdala lesions don't
interfere with hippocampal-dependent memory in rats or humans.
This is pretty good evidence that the amygdala can't convert a
hippocampal memory into something it can use to do its work. It
doesn't answer the specific question (whether the hippocampus
can read amygdala memories) but it does answer negatively the
reverse question, and seems to suggest that brain areas are specific
rather than universal computers.
Maturation vs. Learning
I think many of the issues raised by Steve Pinker about the
evolutionary and maturational basis of fears and phobias are addressed
in The Emotional Brain. The evolutionary and developmental
researchers that Pinker cites are covered and endorsed there.
I tend to emphasize learning because I want to see how far the
fear conditioning model can go rather than because I think it
can explain everything. Pinker asks whether my account can easily
include the idea that some adult fears and phobias are developmentally
programmed childhood fears that never went away. I think this
kind of idea can fit right in. I view fear learning as something
that a fear detection network does. This network can detect dangers
that are programmed in by evolution, as well as those we've learned
about. Many of the things that make otherwise normal people afraid
are things we've learned about, whereas many phobias seem to involve
things that were dangerous to our ancestors. In either case the
stimulus goes to the amygdala, which unleashes the responses.
The only difference between a learned and an innate releaser of
fear responses is how the amygdala was programmed to detect the
stimulus.
While I thus agree with Pinker's point that evolutionary and
maturational factors are important, I'd like to add a couple of
additional points of support for the role of learning. First,
there are some instances of phobia where there is a triggering
event, even if this isn't always the case. Second, certain evolutionarily
programmed fears have to be massaged by experience, as when baby
monkeys need to observe snake fear in others once in order to
express it themselves. Third, not all learning is associative
in nature. Jake Jacobs and Lynn Nadel have in fact raised the
possibility that non-associative processes might be important
in getting phobias going in some cases. A related notion comes
from Jay Schulkin and Jeff Rosen, who are proposing that amygdala
kindling might be a kind of non-associative neural trigger of
phobias. Finally, some phobias involve non-biologically relevant
stimuli, like cars and elevators. Here experience (associative
or non-associative) would seem to be key.
Pinker also asks about the maturation of the amygdala. There's
not a lot of work on this. Just as emotion has been ignored by
cognitive science, the amygdala has been ignored by neurobiology.
The neocortex and hippocampus, the king and queen of cognition,
have been preferred targets of study. However, here's what the
data available suggest. The amygdala matures relatively early
after birth, whereas the hippocampus comes in much later. Jacobs
and Nadel have suggested that the late development of the hippocampus
accounts for infantile amnesia, that inability to consciously
remember what happened to you in early childhood. However, because
the amygdala is up and running, it can form its memories. A child
that's abused will then have unconscious (fear conditioned) memories
throughout life, but will never be able to verbalize why he reacts
the way he does. That the amygdala never forgets is suggested
by lots of evidence, again documented in The Emotional Brain.
The amygdala's memories can be inhibited (by extinction or therapy
processes) but these extinguished responses (unconscious implicit
memories) can usually be brought back. They return as implicit
not as conscious memories.
Pinker's final point is about why the cortex and amygdala are
asymmetrically connected — the connections from the amygdala
to the cortex are stronger than the other way around. He suggests
that this may have a purpose — lack of cognitive control
over emotion can be an asset in strategic conflict, since it makes
threats more credible. His alternative is that there's some kind
of evolutionary inertia that prevents the development of symmetrical
connections. I prefer the second choice over the first, mainly
because it's grounded in "brain" rather than "mind" evolution.
In any event, as Pinker points out, now that we've pinpointed
the kinds of circuits that are involved in fear, we can begin
to ask the really interesting questions about how that system
relates to the rest of the brain, and that's going to help us
understand the cognitive/emotional mind, or, in other words, the
real mind, as opposed to the one that much of cognitive science
has been stuck on.
JOSEPH
LEDOUX is the Henry and Lucy Moses Professor of Science at
the Center for Neural Science, New York University, and author
of the recently published The Emotional Brain: The Mysterious
Underpinnings of Emotional Life. LeDoux's home page contains
additional information about his lab's research.
THE THIRD CULTURE
"COMPLEXITY AND CATASTROPHE"
A Talk with John Maddox
John Maddox, who recently stepped down as editor of Nature, occupies
a unique place in today's culture. During the past 23 years he
managed to build Nature into the premier publication of
its kind, while still retaining the respect of the international
science community for his intellect and writing.
In this discussion he talks about what we need to be concerned
about: the increasing accumulation of data on a huge scale, lack
of quantitative progress in biology, infection, impact, cloning,
and the stability of the human genome.-
JB
SIR JOHN MADDOX, who recently retired having served 23 years as
the editor of Nature, is a trained physicist, who has served
on a number of Royal Commissions on environmental pollution and
genetic manipulation. His books include Revolution in Biology,
The Doomsday Syndrome, Beyond the Energy Crisis, and the forthcoming
What Remains to be Discovered: The Agenda for Science in the
Next Century (The Free Press,US; Macmillan, UK)
"COMPLEXITY AND CATASTROPHE"
JB: Let's talk about the questions you're asking yourself.
MADDOX: There's an extremely interesting question that seems
to me to be very urgent: how on earth is science going to cope
with the accumulation of data, on a huge scale, of recent years.
This relates to another question that hasn't been given enough
attention in recent years: when on earth is biology going to become
a quantitative science, like physics and chemistry - when there's
good evidence to believe that it can't make progress in some fields
without becoming much more quantitative.
Let me give an illustration of what I mean. In a field like
cell biology, everyone now has a clear picture of how the cell
cycle is driven. You have proteins called cyclins, which are meant
to interact with another protein called Cdk. Cdk plus cyclin activates
two successive steps essential to the cell cycle. One of them
is the replication of the cell's DNA; the other is the actual
fission of the cell into two daughter cells. It seems to me high
time that people recognize that the complexity of this system
is so great that it can't really be dealt with in the simple way
in which textbooks ordinarily deal with description, i.e. the
explanation of events.
If, for example, you have an ordinary bacterial cell going through
the process of cell division, it may be prompted to do that by
some external signal in the environment; it may be prompted to
do it simply because time has passed - twenty minutes is the length
of time it takes the E. Coli to divide into two, and maybe just
twenty minutes is up. There are several different molecular influences
acting on this complex of cyclin and Cdk which is what actually
triggers off the cell division. The complexity of the problem
is so great that you can't comprehend it in the language I've
been using; you can't comprehend it in the language of the textbooks,
because it has become a mathematical problem. Nevertheless, very
few people take this seriously.
There's more to it than that. I'm advocating that in the case
of the cell cycle this is a specific biological problem. How do
we understand the cell cycle? What makes a cell divide? What can
we say about the competing influences on a cell - the external
environment, the internal need of the cell, the need of some other
cell in the same organism. How do these competing influences conspire
to decide that the cell is now going to divide into two. What
we need are mathematical models for saying what actually goes
on.
There are other fields like that. Take the way in which the
muscles in our arms work. Any molecular biologist will now tell
you this understanding is one of the big triumphs of the past
ten or fifteen years, that muscle fibers are made of actin and
myosin, two proteins - and the idea is that the myosin molecule
which is smaller than the actin molecule, acts as a kind of enzyme
at the head of the actin fiber, that can ratchet itself along
a parallel actin fiber.
Molecular biologists say, ah, we now understand how muscles
contract. But nobody has done the thermodynamics of this problem.
It's obviously a matter of great interest to the world at large
to know how much energy is used. The molecular biologist will
tell you it comes from ATP. ATP, adenosine triphosphate, is actually
the universal source of energy in living cells, and everyone says
that's fine, but actually what are the thermodynamic aspects?
This question is not considered, and it's a crucial question,
because that's the kind of consideration that would tell us when
it is that muscles become tired, when they no longer function,
or when they become rigid, and go into spasm. There are all kinds
of important abnormalities in muscle behavior that would be explained
by thermodynamics, if people put their minds to the task. The
molecular biologists may have answered the "how ? question, but
they will not be able to answer the "why?" question until somebody
has done the thermodynamics.
What I'm saying underneath all this is that perhaps molecular
biology got itself into the condition in which it's far too easy
to get data, and therefore there is no incentive to sit down and
think about the data and what they mean. But I'm sure that as
the years go by, and not many years, people are going to have
to be thinking much harder about how they get accurate quantitative
data about the behavior of cells, muscles - all these things in
living creatures.
JB: What is the relation of the acquisition of such data to
the development of technological tools that allow you to formulate
models and execute on those models. Are your perceptions related
to the development in increased computational power?
MADDOX: The case I'm making actually doesn't depend on the improvement
of computer technology, but what you say is absolutely right;
that to solve some of these problems is going to require unprecedented
computer technology. But let me illustrate it this way: suppose
you want to understand how a cloud functions, a cloud in the sky.
Sometimes you get rain out of a cloud, but not always - you see
clouds up there but no rain coming out of them. Why is that? The
reason is that in a cloud you have a constant upward and downward
flow of drops of water, particles of ice and so on, and it's in
a dynamic situation. For every cloud the bottom is at some temperature
and the top is at another temperature - a lower temperature, of
course. Sometimes this dynamic stability of the cloud becomes
unstable, perhaps because there's a shift of the temperature,
perhaps because something goes through it like a projectile, an
aircraft perhaps which may leave a trail of condensation behind
it if it's travelling through the humid atmosphere, But you can
only understand cloud behavior and answer the question when will
this cloud produce rain, if you have a model which can be in that
case quite a simple model.
In the case of the cell, and the cell cycle, it's a much more
complicated model I'm looking for, and there in reality one would
need supercomputers to handle the model The models people have
built so far - I'm thinking of John Tyson at the Virginia Polytechnic
and Albert Goldbeter at the Free University in Brussels -have
been handled on ordinary desktops, but everyone agrees they're
not sufficiently refined. Once you start refining them you get
into real problems. But there's some parts of science that can
only be understood when you make a model. The cell cycle is one,
the muscle is another, and each of them, being biological problems,
are very complicated.
JB: Speaking of cells, let's jump off this track for a minute
and talk about the cloning experiment in Scotland. People are
having a hard time getting their heads around it.
MADDOX: I look at the scientific importance of that experiment
in the following way: it seems to me is that it is a demonstration
that you can take an ordinary cell from a person's body, a somatic
cell as it's called, and recreate the genome from that. The reason
that's interesting and important is that up until now people haven't
been sure whether the DNA in every cell of our body retains the
power of making an embryo. This experiment shows that that happens.
You can in principle take a cell from your skin or anywhere and
make it into an embryo which then grows up into a person. That
rules out a number of possibilities for the ways in which different
tissues of our body have their different characteristics. Now
a liver cell and a kidney cell are outwardly very different; a
skin cell and a nerve cell are very different to look at, in their
properties, and their behavior. But in practice, the difference
could be because their genes have been changed in some way. This
experiment in Scotland shows their genes have not been changed
radically. They've been silenced, perhaps, but only temporarily.
That's very important.
Now as to the practical importance, it seems to me that the
immediate value of it is in animal husbandry, and that is in those
fields where people have been trying to use sheep, or pigs, or
cows, to generate biochemicals - to make medicines in sheep. There's
a lot of interest in this. The procedure is quite simple: you
introduce the human gene responsible shall we say for making insulin,
into sheep, and then you collect the insulin from the sheep, and
you find it's human insulin, not sheep insulin. Thus you have
natural human medicine generated on a farm.
This kind of work is very difficult, because it's very much
a matter of chance to where the human insulin gene will go. If
you can take a successful chance, a case where the gene has gone
in the right place and it's producing in the sheep a lot of insulin,
then you can clone that sheep and get many many other sheep. You
don't have to rely on chance any more. So that's going to be the
immediate practical value.
The dangerous question is what happens when people start doing
it to themselves - to people. For what it's worth, in Britain
and many other countries, it's against the law to do this; it's
a criminal offense to manipulate the human embryo beyond 14 days
of life, and it's in fact a criminal offense to do so without
the approval of a licensing authority. How effective that interdiction
would be in other countries is anybody's guess. My guess is that
countries like Morocco, which has been in the vanguard of sex
change operations for many, many years will be in the vanguard
of people cloning. So in that spirit, it's a question of waiting
to see how the technology works out, and trying to get some kind
of international understanding on the circumstances where it would
make a lot of sense.
Are there any circumstances in which it would make a lot of
sense? I can think of one. Coming back to one of the other questions
I mentioned at the beginning, suppose we got into a situation
where we had reason to believe that there was something wrong,
something inherently wrong, with a set of genes that people have
inherited, which have been evolved, of course, over the past four
and a half million years, since we separated from the great apes.
Suppose that we had reason to believe that one of those genes
was going to cause trouble as time went on. For example, there
is a case which one shouldn't make too much of, but's it's an
illustrative case, of Huntington's disease, where there's a normal
gene in every one of us, which makes a protein called huntington
- nobody knows what its function is. This gene - this gene at
cell division, when people procreate, produces a bit of nonsense
at the end, and if the bit of nonsense is longer than a certain
amount, it actually gives a person Huntington's disease - and
he or she dies. That's bad news. There are half a dozen other
diseases like that, same unbalanced mechanism. If there were a
lot of those incidences, you could pretty well say that the time
will come in the evolution of people when we'll all be dying of
Huntington's. One way of avoiding it would be to clone people
who didn't have this propensity. That's about the only circumstance
in which I can see people cloning, as the last resort for the
human race to avoid a calamity that would be brought about by
gross instability of the human genome. I'm not saying that this
is a real prospect now, but maybe in a hundred generations it
could be.
JB: What other areas are causes of concern to you?
MADDOX: I've got a very simple view about the environmental
problem that we all know about which is that a great deal of the
excitement there's been in the past 25 years about the environment
can be boiled down to this: one can say look, you can get whatever
environment you wish, provided you are prepared to pay for it.
You can get air as clean as you like, water as clean as you like
provided that taxes, and the regulation of the private sector
is tight enough to meet the standards laid down. This does mean,
of course, that the countries that can afford a clean environment
are the rich countries, and the environment they purchase is a
big purchase - sometimes out of public funds, sometimes out of
private funds. Poor countries can't afford a decent environment,
but as they get rich they will enjoy the wealth necessary to make
them see that a clean environment is good for them.
The real environment problems now, it seems to me, are things
like infection. We've had AIDS pop up since the early 1980's;
it's been a big shock to people that there could be such a completely
novel disease doing such terrible damage and apparently untreatable
by existing remedies. It's my belief that there must be many other
diseases like this waiting for us as the centuries tick by. Suppose,
for example, that there were a really infectious cancer virus,
something which could just give you lung cancer if you took it
in as if it were flu. There's only one known human cancer virus
at present, but there are many in the cases of domestic animals
like cats, such as the leukemia virus that's well known. The only
human cancer known is papilloma virus which causes cervical cancer.
And we all know that quite apart from these bizarre novel viruses,
there are ordinary bacteria, like E. Coli, that from time to time
acquire mutations that make them more virulent. The new E. Coli
strain 170, for example, has caused a lot of damage in the United
States, in Japan, and now in Britain. Dozens of people have died
of food poisoning, in effect.
These bacteria are going to become more and more common as the
years go by because we are putting the bacteria under such enormous
pressure with the intelligent use of antibiotics in hospitals,
curing the sick, and so on, the bacteria really have nowhere to
go unless they become more virulent.
So we must expect that however good the defenses are - by defenses
I mean the drugs, the hygiene - the bacteria are going to keep
on getting more virulent unless they can be really hit hard. We
have the prospect ahead of us of increasing threats from viruses
and bacteria, and the organisms that cause diseases like malaria.
It's actually part of the price we pay for living longer, for
being healthier. It's just one of those things, something that
one ought to reckon with, not wring one's hands about.
There's another worry, one which perhaps sounds unreasonable.
I believe that it's only a matter of time before the world will
have to plan to avoid catastrophe by the impact of asteroids.
It's now known that 64 million years ago the Cretaceous Period
and the dinosaurs were brought to an end because there was a big
impact of an asteroid ten kilometers across - about six miles
across - the impact site has been found on the Caribbean coast
of Mexico, and the crater it left in the ground is 180 kilometers
- about 110 miles across. It put up dust into the atmosphere,
and the dust stayed there for so long that the vegetation died
off, and the dinosaurs that ate grass died off with it, and lots
of other species as well. That kind of event is likely to recur
every few tens of millions of years.
Luckily, the techniques are good enough to be able to pick up
about 90% of the objects that size in the neighborhood of the
earth. They're called asteroids, or they may be comets. The biggest
difficulty is that of a cometary impact because comets travel
at a faster speed than asteroids and the warning would be less.
But if you think that the whole world was put to an end 64 million
years ago pretty well, by one impact, is it not sensible that
the human race should do something to protect its own stake in
the future? I believe we should be planning to do something about
events like that that might happen in the future. Of course smaller
impacts can do a lot of damage too. I think it's only a matter
of time before people will be setting out to track those things,
and to destroy them.
JB: How will this be implemented?
MADDOX: There are lots of very interesting problems that people
haven't really thought about; for example, the best way of avoiding
an impact is to explode a nuclear weapon near the projectile.
If you can catch it early enough, shall we say several days before
it's going to hit the earth, then a quite small nuclear weapon,
shall we say 100 megatons, would be enough to nudge it in one
direction or the other, but the most efficient way is actually
to slow it down; to explode the thing in front of the asteroid.
There are a number of associated hazards - if the explosion were
not absolutely accurately timed, it might blow the asteroid up,
and that might seem good news except there would then be several
fragments, and one of those would certainly hit the earth, and
it might still be quite big. So the best thing is a carefully
controlled explosion to nudge the thing away.
The trouble with that is that the Russians and the United States
are now against the deployment of nuclear weapons in space; the
Chinese are probably against the development of other people's
nuclear weapons in space; nobody has talked about the question
anyway. So the idea that it might be announced there's going to
be an impact a year from now wouldn't actually leave enough time
for people to get around the table and decide what best to do
about it. My own opinion is that there's going to have to be rather
formal negotiation quite soon on what would happen if there were
an impending impact. There would have to be arrangements that
would make sure that no nuclear weapon authorized for use under
this program could be used to divert an asteroid onto some sensitive
part of the world, like China or Russia - and so on. All kinds
of problems.
JB: How much time would we have?
MADDOX: It depends. In the worst case there would be hardly
any warning at all - a couple of days. A couple of days is too
little time to do anything. And the chance that a large object,
ten-kilometer object, would arrive with only two or three days'
warning is probably about ten percent. No program that one can
think of devising is going to avoid the worst case - you can't
get absolute security - but you could at least hope to get rid
of ninety percent of the big impacts.
In the case of asteroids, the warning probably would be quite
long, possibly even two or three years, because these asteroids
make circuits about the sun just like the planets do, but they
go in eccentric orbits, which is why they can hit the earth. This
means that if you pick one up on a particular orbit, you might
be able to figure out that on its next orbit, or its next but
one, it's going to hit the earth. You've got quite some time to
plan what to do in that case. And the feasibility of doing something
will of course improve as time passes, so in that case one could
begin by hoping to avoid half the large objects, quite soon, and,
maybe in a hundred years, to avoid ninety percent of the large
objects. However, we'll still be stuck with the problem of the
ten percent.
JB: How do these ten percent sneak in?
MADDOX: They begin as comets and the thing about comets is that
nobody is entirely clear how they find their way into the inner
solar system. The theory - and there's no confirmation of this
at all - is that right at the edge of the solar system, roughly
at the place where the sun's gravitation field is comparable with
the gravitational field due to external objects, like molecular
clouds, other stars, and so on - there's a cloud of cometary material
called the Oort Cloud, named after the Dutch astronomer Van Oort.
What's said to happen is that these objects are either deflected
into the solar system by a passing star, or attracted in by some
conjunction of one of the outer planets with Jupiter, so that
they start drifting into the solar system.
They spend some time with Neptune, and some time with Saturn,
some time with Jupiter, and either they become asteroids, in which
case there's relatively little problems, or in some extreme cases
they start heading in from the outer region of the solar system,
and they just make one pass at the sun. That's the most dangerous
case, because these hyperbolic comets, as they are called, are
traveling very fast, and they haven't been seen before, and they
will only make one pass at the sun anyway. In that case it would
really be quite hard to be sure that one could spot them many
days in advance of an impact. That would be curtains.
JB: Ok, we've talked about data handling, infection, cloning,
and impact. Going beyond cloning, let's talk about the stability
of the human genome.
MADDOX: I dealt with that in the case of the sheep but let me
add this to it, because I think it's important. Up until now it's
been the assumption of most generations living on the surface
of the earth, that the ideal condition of human beings is that
in which we recognize that we're a part of the natural world,
and our goal is harmony with the natural world. If you think of
it, what natural selection, Darwinian natural selection, does,
is precisely to make the successful species, those that survive,
fit for the environment at the time. It's a device for making
sure that everything is in harmony with the natural world. We
have accepted, I think, as the human race, that this is indeed
the case, that we must accept our dependence on the natural world
and our need to be in harmony with it.
What happens, then, if we learn that we are one of those many
species destined to become extinct because for some reason or
another our genome hasn't worked out to be quite as stable as
it might have been. In those circumstances we would have a nasty
choice. We would have to decide, would we not, whether or not
we let ourselves become extinct, as part of our dependence on
nature, part of our being a part of nature, or whether we actually
struggle against it; do something about it.
My guess is that if the question of human extinction is ever
posed clearly, people will say that it's all very well to say
we've been a part of nature up to now, but at this turning point
in the human race's history, it is surely essential that we do
something about it; that we fix the genome, to get rid of the
disease that's causing the instability, if necessary we clone
people known to be free from the risk, because that's the only
way in which we can keep the human race alive. A still, small
voice may at that stage ask, but what right does the human race
have to claim precedence for itself. To which my guess is the
full-throated answer would be, sorry, the human race has taken
a decision, and that decision is to survive. And, if you like,
the hell with the rest of the ecosystem.
JB: What are the scientific issues bothering people today that
don't worry you?
MADDOX: It's interesting that more than a quarter of a century
has passed since the publication of The Limits to Growth, the
Club of Rome document, which seemed to me to produce a far too
simpleminded view of the global problem. The global problem is
not the shortage of resources. It's true that we are using up
petroleum at quite a rapid rate, two billion tons a year, and
the amount of petroleum in the surface of the earth is not by
any means infinite. But there's a natural balancing mechanism
in those simple scenarios of shortage. The balancing mechanism
is price. What we're pretty sure of is that we've now used up
one dollar a barrel oil; it's all gone. There's some two dollar
a barrel oil left in Saudi Arabia, but the Saudi Arabians are
very careful about the degree to which they let their stuff be
exploited, and that appears on the market at fifteen dollars a
barrel like everybody else's oil. So price is really a regulator
of scarcity.
Even when petroleum becomes so expensive that it's used only
for the production of chemicals - some of the few chemicals that
can be produced exclusively from petroleum - the world will not
stop. There are plenty of other ways of generating energy which
at present are more expensive than petroleum - like nuclear power,
even solar power, in small quantities, like hydrogen, which can
be made by electrolyzing water, and used as a fuel - so there
are all kinds of ways. The future is going to be dependent upon
on other sources of energy than the ones we at present use.
The argument that we're using scarce, irreplaceable sources
of energy is an argument not worth its salt; not worth listening
to seriously. We're using up cheap resources, and in due course
we're going to have to use more expensive ones, which is an argument
of course for wealth creation, economic growth. So my view of
the Club of Rome's argument on the Limits of Growth is just that.
It's an economic question, always has been, and it will be in
the future and it will be dealt with in economic terms.
But the other environmental problems that seem to me to be much
more important, are those concerning the safety of people's lives.
After all, the avoidance of pollution is primarily a problem of
how do you keep people healthy. That's what the end purpose is
supposed to be, keeping people alive and healthy. The big threat
there has been, and remains, infection, which we've talked about.
It seems to me another is global warming. Global warming is the
scenario that's supposed to happen when, because of the accumulation
of carbon dioxide in the atmosphere, the temperature on the surface
of the earth is increasing. I'm in a very odd position on this.
I accept that global warming, because of carbon dioxide, is going
to be a reality at some stage in the future. I disagree with the
way in which the forecasts have been made by the organization
called the Intergovernmental Panel on Climate Change, which is
under the UN umbrella, although it's really a child of the United
Nations Environmental Agency and the World Meteorological Organization.
These people have produced so far two assessments of the seriousness
of global warming, and they predict that during the next century
the temperature will increase by between two and three degrees
centigrade - which doesn't sound much but actually would be a
lot. This is the average temperature, and that would mean that
in places like the southern Sahara it would become even more like
a desert, and it might even mean that in some parts of the United
States, like Texas, it would become a bit like the Sahara.
But the real problem is that all this is based on computer modeling,
and while I'm fully enthusiastic about computer modeling as a
way of understanding scientific problems, and comprehending large
amounts of data, I think it's dangerous to rely on computer modeling
when you are trying to make predictions about the real world.
In fact the satellites that have been used to measure the temperature
show that the temperature is increasing less rapidly than the
computer models predict, by a factor of three. So I think that
the scenario is less gloomy than the Intergovernmental Panel of
Climate Change says.
On the other hand, it's going to happen sometime, and we have
to do something about it. It raises the whole question about how
do you get an equitable relationship between the rich and the
poor countries. The rich countries have to acknowledge that they
can't unilaterally deny developing countries the right to follow
in the same kind of path as they themselves have followed in their
own economic development. On the other hand, the poor countries
have to accept that they can't let their demands on the global
system increase as rapidly as their populations increase. They
have to accept some kind of restraint on population as a tradeoff.
That's going to be such a terribly difficult negotiation and it's
very hard to see how it could be completed in the next century.
