LIFE'S GRANDEUR:
The Spread of Excellence from Plato to Darwin
By Stephen Jay Gould
Jonathan Cape, 244pp
AT HOME IN THE UNIVERSE: The Search for Laws of
Complexity
By Stuart Kauffman
Penguin, 321pp
PLAN AND PURPOSE IN NATURE
By George Williams
Weidenfeld & Nicholson, 191pp
Natural diversity, Stephen Jay Gould tells us
like a slap in the face, is usually attributable to nothing more interesting
than a drunkard's walk away from a wall. Wherever she goes, the drunk will end
up either smashing into the wall, or she'll topple, after a meandering course
along the pavement, into the gutter. Dangerous metaphor, that, but Gould does
not intend to denigrate humanity--just to rebuke our hubris.
Emergent life starts simple (against the `left wall' of the complexity
chart) because it can't start any other way. Mostly it stays simple. Even
now, arguably, most of the earth's biomass is elegant, uncomplicated bacteria.
Recently, archaic forms of life have been found dwelling happily deep under the
crust. As much living material, simple but persistent, might be spread under our
feet as floats and gallops and soars in all the familiar habitats of the globe.
Life, of course, never stays still. Mutation gnaws at each DNA message,
and ruthless environmental selection winnows the alternatives. Over time, some
variants grow more complex, wandering off toward the open-ended or righthand
edge of the chart. Others wander back again. Humans and other large animals
exist way off on the right-most tail of the curve. Wow, so that's what
it's all about--evolution's surging life-force has been struggling to create us!
Before Darwin, people supposed that God had done the design-work.
Evolution hinted that we could replace God-the-designer with some kind of drive
toward complexity. Sadly, that notion is probably just as erroneous and
self-preening. It's true that some forms have grown more complex in the billions
of years since life's emergence on Earth. But this is not, Gould asserts,
because there is any `complexification drive'. It's a side-effect of the wall
over there on the left, and the vast eons of life's drunken stumbles.
One objective test of this anti-progressivist thesis is to ask: are
ancestors simpler or more complex (by some measure) than descendants?
Startlingly, Dan McShea's landmark studies show a random balance of the two
directions. McShea is now at the
Santa Fe Institute, the world's Mecca of complexity theory. He finds that
diversity is better explained by `passive' than by `driven' trends--the
drunkard's walk. Summarised deftly by Gould, the argument seems solid.
I wonder what the other Santa Fe folks make of this. When Roger Lewin was
writing his excellent 1993 popular science book Complexity, Stuart
Kauffman, one of their notable gurus, urged him to consult McShea. The reductionist Richard Dawkins, at the other extreme, also
insists that there's no tendency in evolution toward greater complexity, merely
toward successful adaptation to fortuitously changing conditions.
But evolution is modulated by a ceaseless `Red Queen's race', in which
species are obliged to alter swiftly just to stay abreast of their
competitors--to run as fast as they can, as Lewis Carroll put it, in order to
stay where they are. So among Dawkins' environmental conditions are other
contestants. One might, therefore, expect a driven complexifying trend to show
up. Not so, insist Gould and his sources.
Incidentally, for baseball fans, Gould uses a delightful analogy to
convey the force of his perspective. Why has 0.400 or near-perfect batting
vanished? Gould shows it's due not
to decline but to general improvement of the game (technically, the
closing up of variance), in an argument both beautiful and compelling.
I wonder if this apparent paradox helps explain the observed difference
between males and females on many aptitude tests. Perhaps general excellence in
females permits less opportunity for extreme outliers, so the much discussed
`absence of women geniuses' is an artefact of the metric used to rate their
success. Probably not, since both sexes are tested by the same instrument and
their scores can be compared directly. Still, it might have some bearing on an
issue generally settled by fiat or force...
Can Gould be correct about life's ambling course? Is it possible that
there's really no drive toward complexity? When G. Boyajian and T. Lutz examined
the fractal twistiness of ammonite sutures, often held to show increased
elaboration with time, they found no historical bias toward complexity. What's
more, there was no correlation between complexity and species longevity. Even if
your species is more elaborate, with scads of additional DNA coding, it is just
as likely to go extinct as its simpler relatives.
The argument, however solid, has little bearing, of course, on purely
cultural change. The drastic social and technological shifts that are rushing at
us with increasing speed are the product of memes - the `Lamarckian' units of
human minds and passions - rather than the raw Darwinian contest of genes.
Stuart Kauffman, who represents the alternative point of view, insists
that self-organisation is a hallmark of life in our universe. For Kauffman,
"the emerging sciences of complexity begin to suggest that the order is not
accidental, that vast veins of spontaneous order lie at hand." If Gould
insists that re-playing the tape of evolution from the start would not produce
us humans, Kauffman can readily agree, while holding out for a different but
related claim. "The particular branchings of life... might differ, but the
patterns of the branching... are likely to be lawful."
His conclusion sounds like the sort of mystical assurance Gould loathes:
"I am heartened by a view of evolution as a marriage of spontaneous order
and natural selection. I am heartened by the possibility that organisms are not
contraptions piled on contraptions all the way down, but expressions of a deeper
order inherent in all life." Nowhere in either this more accessible
treatment or in his magnum opus, The Origins of Order, does Kauffman cite
McShea's studies suggesting that the contrary is the case. Funny, that.
George Williams is one of the world's leading evolutionists, closer to
hard-ball Dawkins than to either Gould or Kauffman. Unlike Gould, he favours `adaptationist'
accounts, seeing in the record less random wandering and more brutal herding.
And he exiles Kauffman to his footnotes, while concurring in the importance of
`spontaneously occurring' order, the great Santa Fe theme. "One of the
great delights of scholarly pursuits such as biology," he remarks, "is
that we can all form our own opinions." In many cases, he stresses,
"the jury is still out".
I think all three very different perspectives would agree with Williams'
moral outrage at evolution's stupidity and cruelty. "Organisms," he
argues, with plenty of gruesome instances, "show the expected stupid
mistakes, the dysfunctional design features, that arise when understanding and
planning are entirely absent." The title of his excellent Science
Masters' volume is bleakly ironic. Happily, as he urges, "we can have
some hope that our intelligent efforts to circumvent the evil can triumph over
so unreasoning an enemy."
KINDS OF MINDS:
Towards an Understanding of Consciousness
By Daniel C. Dennett
Weidenfeld & Nicolson, 184pp
HOW BRAINS THINK: Evolving Intelligence Then and
Now
By William H. Calvin
Weidenfeld & Nicolson, 184pp
THE CONSCIOUS MIND: In Search of a Fundamental
Theory
By David J. Chalmers
Oxford University Press, 414pp
The proper study of mindkind, as the 18th
century poet Alexander Pope didn't quite say, is mind.
That isn't a slur on the human body, on our passions, intuitions,
blood-thrilling joys and sorrows. Mind, or consciousness, just is the body
experiencing its rich throng of impressions and thoughts, recalling the past,
relishing the present and preparing the future. So runs the consensus of today's
experts in the cognitive and neuro-sciences.
Not everyone agrees. Many religions teach that each human is a kind of
metaphysical siamese-twin, brute matter yoked to sublime spirit. Our suffering
atoms might disperse upon death, but soul, mind, spirit (not synonymous, but
linked in their ineffability) persist and find justice or at least peace.
While there's no scientific evidence for this claim, adherents find the
strongest proof in experience itself. We know what we are, from the inside. In
the language of philosophers, our most humble experience is drenched in qualia--qualities
of intimate subjective feeling that no PET-scan will ever detect. Qualia, it
seems, are the very habitation of mind. If so, how can mind be nothing more than
the brainy body in action?
William H. Calvin is an imaginative neurophysiologist and novelist, and
Daniel C. Dennett a polymathic philosopher at home in cognitive science and
evolutionary theory. In two brief Science Masters books aimed at
non-specialists, but requiring a bit of attention, these American researchers
show how mind can emerge unmysteriously from complex neurological structures.
Plenty of gaps remain in the chains of explanation, but the story is coming
together. Intelligence, awareness and even consciousness have developed--and
still function--by Darwinian principles.
David Chalmers is no less imaginative, an Australian who started in
mathematics and computing at Adelaide and Oxford before jumping in at the deep
end in Indiana, with Douglas Hofstadter, to explore mind by traditional and
scientific means. Now a professor of philosophy in Santa Cruz, he's at the eye
of a storm stirred up by his formidable new book. The Conscious Mind is much
more strenuous territory than the other two, but luckily Chalmers marks those
especially bristly sections meant for experts in modal logic, permitting lay
readers to slip past them. His claim? Mind has its own special laws, even though
it arises from (or `supervenes upon') matter.
Well, I think that's his claim. Even after 357 pages of closely reasoned
text and 32 pages of notes, I'm still not sure exactly what Chalmers is saying
about `the Hard Problem' (as he notoriously dubs consciousness). Famous
philosophers share my bafflement. The celebrated and feisty John R. Searle
recently got stuck into Chalmers in the New York Review of Books,
declaring his assertions absurd. Chalmers responded vigorously, and the debate
continues.
To me, perhaps the most startling aspect of this stoush is that Chalmers
isn't a desiccated Jesuit or a bald pipe-smoker in a tweed jacket, but a
strikingly good-looking youth with flowing heavy-metal hair. Thanks to the
Internet, you can sample his arguments and view his family, girlfriend and
sports car before buying the book. Handy links on his home site take you to
Searle's article, his retort, and other critical responses--including Dennett's.
While you're on the World Wide Web, check out William Calvin's own lavish
homepage, with sample chapters of his science books, animated diagrams of the
brain at work, and the complete text of his novels. Ideas now swarm around the
world at electronic speed even as we trudge to the bookstore to buy these
bundles of printed paper. Still, I prefer reading difficult ideas in books, and
chasing up the controversy later on the computer screen.
All three of these mind-hunters share a deep respect for the abundant
trove of brain science. As Tom Wolfe declared recently in Forbes business
magazine, of all places, "Neuroscience... is on the threshold of a unified
theory that will have an impact as powerful as that of Darwinism a hundred years
ago." We live in an age, Wolfe noted ruefully, in which it is both
impossible and pointless to avert our eyes from the truth revealed by the subtle
new brain scanning technologies.
Dennett denies that we are intrinsically different from other kinds of
life, even if mind itself is rare. While viruses and bacteria are undeniably
mindless robots bustling in our flesh, we must not "take comfort in the
thought that they are alien invaders, so unlike the more congenial tissues that
make up us." The brain's billions of neurons are cells scarcely different
from those of germs or the yeast cells in beer vats and bread dough. "Each
cell--a tiny agent that can perform a limited number of tasks--is about as
mindless as a virus."
Where, then, does mind comes from? From the organisation, the networks,
the nuanced dance of these specialised ninnies. Not from a mysterious soul,
then, but from the baroque layout of the cellular arrays. Does this mean that
dogs also have minds? After all, their brains and nervous systems are not really
so much more primitive than ours. And there certainly seems to be someone home
there, behind the brown loving eyes. Or is that an illusion, projected by the
human spirit (as we might call our wonderful, vastly complex machinery)? But if
dogs, what of cockroaches? Ants? Rocks? Dogs, Dennett admits, might be a special
case, for they have co-evolved to resemble us in many respects.
Calvin argues that consciousness--or intelligent awareness, at
least--arises because brains are `Darwin machines'. Stimuli from the outside
world (or from memory) trigger specialised parts of our brains into cloning
temporary representations of things we've seen or thought before. The cloned
activation patterns multiply in hexagonal arrays of cells half a millimetre
apart, hungry for brain-space, synchronising, reinforcing or inhibiting each
other. Each is a kind of fragment of a thought or recognition. Calvin's
suggestion is astonishing, testable, and links minds to the rest of the
evolutionary universe.
Meanwhile, Chalmers is unconvinced. One can imagine a world of zombies,
he asserts, just like ours but lacking consciousness. The brains of these
zombies mimic ours precisely, but there's no light on inside. They act and speak
and laugh and `love', but are mere automatons. Since this nightmare is logically
possible, Chalmers says, consciousness must be something over and above mere
neural structure in action.
What is it, then? Information, he says. Not an answer to give the
faithful any comfort, admittedly. Chalmers believes a complex artificial
intelligence system would be conscious. So he does not propose to reinstate an
immaterial soul. He puts it neatly: "Experience is information from the
inside; physics is information from the outside". Inside what, though?
Inside the mind, with the qualia. But that leaves us where we came in. Besides,
I'm not sure we can truly imagine a zombie world, any more than we can truly
imagine a world exactly like ours without heat.
These are books by thinkers at the growing edge of science and philosophy
both. They show us why it is important to keep asking the oldest questions, and
seeking the newest ways to answer them.
by Lee Smolin
Weidenfeld & Nicolson, 358pp
THE FABRIC OF REALITY
by David Deutsch
Allen Lane, 390pp
Let's not beat about the bush--these are two of
the most dazzling books of the century. If their basic claims are correct, our
understanding of life, mind and the cosmos itself will never be the same.
Why is the universe shaped the way it is? What precise shape is that,
anyway? Most of us have never understood quite how large the answers
might prove to be. Smolin, a leading gravitational physicist, and Deutsch, one
of the world's top quantum computation theorists, claim in their distinct ways
that to resolve these questions satisfactorily we must venture into the
infinite.
They are not talking about deity, however. Smolin's story involves
infinities of time, cosmos succeeding cosmos, universes birthing baby universes
that Bang and expand and fade into attenuated death or perhaps crush into fiery
nothing--but not before giving birth to billions of new baby spacetimes of their
own, from black hole wombs.
The core idea is the discovery, crucial to quantum theory, that the
vacuum--emptiness--is unstable, liable to emit energetic particles. At high
enough energies, this flaw in emptiness can buckle inward to form a black hole,
which may then inflate wildly into a fresh spacetime, creating an entire
segregated cosmos. Depending on the interaction laws coded into that cosmos, it
might recollapse in a tiny fraction of a second, or bubble with micro-black
holes that collapse in turn, or even blow out into a starry spacetime universe
akin to our own.
Imagine, then, a fabulous series of bubbles popping in the void. Most
vanish with no progeny. Some persist long enough for their colossal outpouring
of energy to form elemental vibrating strings and membranes, and for those to
coalesce into quarks and electrons, and then into hydrogen and helium atoms. If
the values describing the new universe (perhaps inherited from its parent) are
suitable, its contents will form stars that cook new, heavier elements in their
compressed gasses. Some of these stars, rich in carbon and other key elements,
will explode in thermonuclear glory, their cores sucked down to fecund black
holes, their hot debris seeding the skies with the raw materials of life and new
stars.
In a few universes, Smolin speculates, an extraordinary set of basic
values will coincide, yielding two interesting features: a maximal number of
stars suitable for making black holes (and hence new universes with slightly
variant parameters) and many other stars and their planets suitable for evolving
life, and even intelligence.
A key, and controversial, step in this Darwinian argument is that the
parameters determining the shape of the new cosmos must resemble those of its
parent, rather than being picked at random. Granting this, after a while most
universes in the mega-cosmos will cluster around certain apparently arbitrary
values--the kind that, luckily, produce observers like us. And the beauty of
Smolin's cosmogony is that it's testable. It moves out of the domain of faith
and into that of science.
Alas, he gives no mechanism for mutating the fundamental values, or
restricting them to small shifts. An extreme possibility is that once
intelligence arises by chance and thrives, it will thereafter deliberately
manipulate the parameters in budded universes. Life-supportive universes
(perhaps available for colonisation via wormholes) are thus multiplied. This
wildly ambitious notion has been explored by cosmologist Edward Hamilton in the
sombre pages of the Quarterly Journal of the Royal Astronomical Society,
and perhaps wisely Smolin ignores it.
David Deutsch's shocking idea is even more resistant to the mind's
clutch: he sees every event literally doubled and reduplicated, with small
crucial variations, in trillions upon trillions of diverging parallel realities,
spread through infinite lateral time. If you're having a bad hair day, cheer
up--there's another version of you, in a universe at right angles to this one,
who's doing just fine. And a zillion more, it's true, taking up every
conceivable alternative position in between. Some of them are dead. Some are on
Mars. A few are sharing Graceland with Elvis, who is married to Princess Di or
perhaps to John Lennon.
Neither of these remarkable postulates is freshly minted by Deutsch or
Smolin. Baby universes go back more than a century, Smolin tells us, to Charles
Peirce, semiologist and pragmatist, while the Many Worlds hypothesis was
proposed in 1957 by Hugh Everett, III, who in this universe died in 1982. Until
now, though, nobody had pursued these striking notions with such ruthless
intellectual attack, following them all the way down.
Deutsch, curiously, insists that his outrageous version of reality ought
not surprise us, or at least physicists, since it is simply the best theory
available to science (quantum mechanics) taken perfectly literally without
metaphysical evasions. In a brilliantly effective display, he argues that
something as ordinary as the splash of illumination shone by an electric torch
on a wall can't be explained without acknowledging that a sort of `shadow light'
from many other adjacent universes is leaking into our own, interfering with the
beam we see and blurring its bright sharp disk into concentric rings.
In those universes, naturally, a few photons from our local universe also
leak across, fritzing their beams of light. `It follows,' Deutsch notes,
`that reality is a much bigger thing than it seems, and most of it is
invisible.' Even so, the multitude of overlapping histories is needed to explain
some of the most basic features of our ordinary world. Deutsch argues
ingeniously that DNA sequences performing a given coding function in different
adjacent worlds must be closely similar, while so-called `junk DNA' that litters
chromosomes will vary at random. It is precisely this consistency in
informational structures that marks them off from noisy rubbish, however complex
and elaborate the noise might seem.
This truly weird interpretation of basic science lies, for Deutsch, at
the heart of an emerging four-fold theory of everything we know (which is only a
small part of everything, admittedly). It will condense our understanding of
evolution, theories of knowledge and the quantum, and computation. Those strands
seem very disparate, but he argues powerfully that where they combine we find an
account of reality's fabric that escapes the cold, mechanistic, inhumane
character of standard reductionist science. One of the founders of quantum
computing, Deutsch is no New Ager. His extravagant ideas are worth taking very
seriously indeed.
Can the two new infinities--endless levels of cosmic histories,
incalculable overlaps of variant worlds in the `multiverse'--meet at a single
point? Deutsch told me his own model `is completely consistent' with Smolin's
cosmological theory. `These two types of multiplicity are independent (at least,
according to our best existing theories).' Well, does his claim that we each
live every possible history obliterate morality? If my `free' choice of a good
deed requires that at least one version of me has taken the `evil' fork - not
just that this was in some abstract sense `possible', but he actually must do
the deed - then Mother Theresa was, somewhere in the multiverse, a villain. This
is not a physical
objection to his account, but it seems a
distinctly distressing one.
Deutsch disagreed. `We have to re-learn how to react emotionally to what
happens in other universes,' but he added, `this doesn't mean that events in
other universes have no moral, or emotional value in ours. The weight which we
should attach to them is given by the theory of probability, which also only
makes sense in a multiverse context, but,' he jested, playing on the
mathematician Fermat's remark about his Last Theorem that has puzzled others for
centuries, `which this margin is too small to contain.' I hope he shall attempt
to resolve the matter in a future book. Presumably he has already done so, as
well as failed to, in other universes.