The Mystery of Life
Last month, the New York
Times reviewed a book by Michael J. Behe, a biochemist from Lehigh
University. Titled Darwin's Black Box: The Biochemical Challenge to
Evolution , the book contended that the molecular machinery of living things
works too well to have been produced by chance alone. Life must have been
designed by some intelligent being, possibly one that was divine. Reading the
review--surprisingly respectful, considering that its author was a science
writer--I had to smile imagining the vein-popping fury that it would arouse in
Richard Dawkins. Fools! he would mutter . I am surrounded by
fools!
Dawkins,
an evolutionary biologist at the Oxford University, is "the most brilliant and
compelling propagandist of Darwin today," as Wired recently put it. He
is also an adamant atheist. His work is basically one long argument that
natural selection, and natural selection alone, is sufficient to explain the
seemingly miraculous variety, beauty, and ingenuity of living things. The
mystery of life, he declared in his 1986 best seller The Blind
Watchmaker , "is a mystery no longer because [Darwin] solved it."
Dawkins is one of those rare scientists whose writings both
persuade his peers and charm the public. He excels at coining pithy phrases and
metaphors that express anew the power of Darwinian theory. In his first book,
The Selfish Gene , published in 1976, he set forth his brutally
reductionist view that all organisms are vehicles created by genes seeking to
make copies of themselves. In The Extended Phenotype (1982), he
introduced the notion that culture consists of self-replicating ideas called
"memes." As many profilers of Dawkins have remarked, Dawkins himself is one of
the most successful meme-propagators on the planet.
His latest book, Climbing
Mount Improbable , is erected around yet another compelling meme. Dawkins
asks us to imagine the myriad forms of life inhabiting a vast mountain. At its
foot are the least complex--and hence most probable--organisms, such as
bacteria and algae. On the peaks are species that seem least likely to have
been produced by happenstance, such as spiders, whose webs are marvels of
engineering.
Dawkins
reminds us that natural selection produces such creatures through a series of
incremental steps that "smear out" their improbability over long periods of
time. To reinforce this point, he tells us how he constructed a computer
program that, with only a few rules for guidance, could "learn" to construct
webs remarkably similar to those built by real spiders.
A >s in his previous books, Dawkins' tendency toward donnish
didacticism is more than counterbalanced by the transparency of his prose and
his genuine delight in the intricacies of nature. His description toward the
end of Climbing
Mount Improbable of wasps enmeshed in Byzantine
power struggles with fig trees is a model of nature writing, at once lyrical
and lucid.
In an era
when even reputable scientists indulge in mysticism, Dawkins' rejection of
intelligent design is also bracing. He openly loathes those who discern divine
intentions behind natural phenomena, such as fundamentalist Christians who view
the AIDS virus as divine punishment for sodomites. Dawkins spares no one. He
describes a conversation in which his 6-year-old daughter speculated that
flowers were put on earth to "make the world pretty." "I was touched by this,"
Dawkins recalls, "and sorry I had to tell her that it wasn't true."
Despite its blunt charms, however, Climbing Mount
Improbable strikes me as being the least convincing of all of Dawkins'
books. In focusing on the notion of life's improbability--or lack
thereof--Dawkins has inadvertently drawn attention to the greatest weakness of
Darwinian theory. There has always been something disturbingly retroactive,
after-the-fact, about natural selection as an explanation of life, even when
propounded by someone as eloquent as Dawkins. Life, explained by natural
selection alone, just does not seem inevitable enough.
Addressing
this issue, Dawkins sometimes resembles a flack for Lotto assuring us that
winning the big one is easy. He allows that at first glance, it seems almost
miraculous that Joe Blow would win the $10 million jackpot. But by retracing
the steps that culminated in Joe's good fortune--the printing of the fateful
ticket, Joe's purchase of it at his local liquor store, the selection of that
number by Lotto officials--Dawkins demonstrates that each conforms to
well-understood principles of physics, biology, and social science; no miracles
were required. Well, true enough. But that does not make Joe any less
lucky.
It is not only religious creationists who are
bothered by this problem but also some prominent scientists. At the Santa Fe
Institute, biologist Stuart Kauffman claims to have glimpsed--deep in his
computer simulations--a mysterious "antichaos" force that counteracts the
tendency of all physical systems to drift toward disorder. This force
supposedly makes stars "self-organize" into galaxies, and inanimate molecules,
into living cells.
Other
theorists, notably David Sloan Wilson of the State University of New York at
Binghamton, have proposed that natural selection may sometimes favor
"altruistic" individuals, who sacrifice their own selfish interests for those
of their herd, or their species, or even the entire ecosystem in which they are
embedded. The most extreme version of this concept, called "group selection,"
is Gaia, which suggests that all of life cooperates so as to ensure its
continued survival.
Dawkins has rebutted these notions convincingly, showing
that the phenomena they attempt to explain can all be accounted for with
conventional Darwinian theory. But his defenses of natural selection sometimes
lend it more power than it really has. In one passage, for example, he likens
it to a force or "pressure" that "drives evolution up the slopes of Mount
Improbable." This image offers a grossly distorted view of evolution. For
roughly 85 percent of life's 3.5 billion-year history, it was entirely made up
of single-celled organisms, such as bacteria and algae. Then, for some
reason--we will probably never know precisely why--the era of trilobites,
triceratops, and other multicellular creatures commenced. Viewed this way, the
ascent from the foothills of Mount Improbable to its multicellular aeries
hardly seems inevitable.
Dawkins' own honesty and
thoroughness undermine his case in other ways as well--for example, when he
brings up the origin of life. "My guess is that life probably isn't all that
rare and the origin of life probably wasn't all that improbable," Dawkins
remarks. "But there are arguments to the contrary." There certainly are.
Dawkins himself notes that after decades of searching, scientists have found no
conclusive evidence that life exists elsewhere in the universe. (The discovery
of organic matter in a meteorite, reported in early August, represents at best
an extremely circumstantial piece of evidence for life on Mars.)
Moreover,
as far as we know, life emerged here on earth only once. In spite of the
immensely powerful tools of modern biotechnology, scientists still cannot make
matter animate in the laboratory. They really have no idea how exactly life
began, or whether its emergence was in some sense inevitable or simply a
prodigious bit of good fortune.
Theorists also disagree over why, once life
began, it was able to persist for so long and to proliferate into such an
astonishing variety of species. Dawkins enjoys pointing out that among all the
possible variants of a given species, the vast majority never reproduce; they
are failures, dead ends. There are many more ways to be a loser in the game of
life, he asserts, than to be a success. Surely that holds true for all of life,
not just for its constituent parts. The essence of the selfish-gene model is
that each individual pursues its short-term interests regardless of the
long-term consequences for life as a whole, or even for other members of the
species. Given that premise, why couldn't one species--a bacterium or virus,
perhaps--run amok and destroy all other life on earth before finally succumbing
itself? But life has managed, nonetheless, not only to endure but also to
produce spiders, newts, and congressmen.
I know Dawkins knows how
utterly improbable we are, because I have discussed the matter with him. Yet he
seems to think that if he allows us weak-minded mortals to perceive that naked
truth too directly, we will succumb to creationism or mysticism or theories
such as Gaia, which is wishful thinking dressed up as science. Of course, most
of us will succumb. But Dawkins should at least give us the chance to savor one
of the great paradoxes of our era before we slip into darkness: The more that
science explains our existence, the more implausible we seem.
