BOOK REVIEW
"And Gladly Wolde He Lerne and Gladly Teche"
Robert J. Richards
(Also see our online
interview with Richard Dawkins regarding this book.)
The Ancestor's Tale: A Pilgrimage to the Dawn of Evolution.
Richard Dawkins. xiv + 673 pp. Houghton Mifflin, 2004. $28.
Popular science writing is, for the most part, undertaken by two
different, if sometimes intersecting, classes of author: the
intelligent general writer, often a journalist who has a deep
interest in a particular scientific subject; and the versatile
scientist who can place easy hands on a keyboard. Some writers in
the former group, such as Richard Rhodes, interweave personality and
topic to produce a compelling narrative. Others, such as Roger
Lewin, write so clearly and vividly that the essential features of
their subject stand out in bold relief, giving readers entrée
to an often-forbidding scientific domain. Scientists who attempt the
genre may display those same virtues, and the very best write with
an authority that commands the attention not only of a literate
public but of their colleagues as well. In their popular writing,
these latter can even shift scientific discourse and bring forward
new theories, or at least new perspectives.
During the last 30 years, biology has been served by several
scientists who have succeeded in altering the terrain of their
discipline not just through technical articles and books but also
through the medium of popular science writing. Two of the very best
have been the late Stephen Jay Gould and Richard Dawkins. Gould was
the more prolific, although Dawkins is hardly a slouch, having
published eight books, including The Selfish Gene, The
Blind Watchmaker and now The Ancestor's Tale: A
Pilgrimage to the Dawn of Life.
Gould's last book, The Structure of Evolutionary Theory,
ran to some 1,400 pages, into which he crammed most of the major
ideas and historical perspectives he had cultivated during his
career. Although that book might seem to have slipped the boundaries
of popular science, at $39.95 it was priced to garner a large
audience—a buyer could almost resell it for scrap paper and
recover its cost. It displays many of the virtues of his other
popular pieces and some of the vices of his later work, such as
verbosity carried aloft on an inflated ego.
The Ancestor's Tale, at half the length of The
Structure of Evolutionary Theory, still has considerable
heft. Dawkins's book, though, displays a properly proportioned sense
of its author's accomplishments. Yet it does have the feeling of an
academic's large portmanteau, one quickly stuffed with odd books,
papers and mismatched socks, rather cumbersome for lighter travel.
In order to assess the good, bad and indifferent in the volume, I
would like to examine more generally the several features of popular
science writing that it exhibits.
The most obvious criterion for something being labeled a work of
popular science is authorial intention. Does the writer wish to
reach a general audience, even if he or she is a scientist hoping
also to entice colleagues? Intention is not an infallible mark,
however. In Newton's Principia for the Common
Reader, for example, Subrahmanyan Chandrasekhar uses
sophisticated contemporary mathematics to explore Newton's own
demonstrations of theorems; the book would challenge the most adept
mathematical physicist and leave the common reader gasping for
breath. (The publisher could hardly have had exalted hopes: Although
the work is less than half as long as Gould's book, it is priced
more than four times as high.)
Dawkins does invite an intelligent but untrained reader, whom he
graciously attunes to a medley of topics regarding evolutionary
biology. He adapts the narrative device of Chaucer's Canterbury
Tales to frame a regressive journey through our evolutionary
past. Starting with modern humans, he draws the reader back in time
through a succession of species ever more remotely related to us.
And for those species he contrives tales of evolutionary import that
are supposed to be something like the diverting stories told by
Chaucer's pilgrims during their travel. But Dawkins quickly abandons
any pretense that his creatures actually narrate the tales he
assigns to them—after trying for one sentence to have the
star-nosed mole say something to the duck-billed platypus, he
decides that "it won't do ... I'll ... revert to my practice of
telling the tale itself in my own words."
Dawkins begins the journey with a chapter that descriptively passes
through archaic humans (including Neanderthals) to Homo
erectus, Homo habilis and the australopithecines,
relating something of their history and our way of understanding
that history. He then moves to the first instance of a
"rendezvous" with "the common ancestor"—in
this case, the ancestor humans share with the chimpanzees, our
nearest living relatives. Thereafter, Dawkins recedes to the second
rendezvous, where the human and chimp lines merge with that of the
gorilla. There he recounts "The Gorilla's Tale," the story
of the discovery of that shy but massive creature in the 19th
century. Dawkins then successively regresses first to the ancestor
that humans, chimps and gorillas share with the orangutans, then to
the ancestor those four species share with the gibbons, and so on.
Each rendezvous point takes the reader back through long stretches
of geological time, repeatedly seeking the common ancestor—or
"concestor," in Dawkins's confection—of a steadily
growing group of "pilgrims" ever more remote from human
beings. These fellow travelers include marsupials, amphibians, sea
squirts, sponges, plants and eubacteria. The journey ends at the
metaphorical Canterbury—the first breath of life, the first
kind of replicating molecule.
The Chaucerian framing device, which takes the reader back through
some 40 rendezvous points and more than 50 tales, has a friendly
intention. Yet it forces Dawkins to assign to creatures some very
odd and only very loosely connected stories—the cauliflower's
tale, for instance, is about scaling relations of body size to brain
size and metabolic rates. The tale is plain and easily digested, but
a weary traveler at rendezvous 36 might crave something more
enticing. The concestors we meet along the way take on an ever more
ectoplasmic existence, finally becoming barely imagined
creatures that have left little trace in the historical record or in
Dawkins's book.
A second criterion of good science writing is intelligibility.
The Ancestor's Tale fulfills it admirably. Dawkins
writes clearly, keeping jargon to a minimum, and the book is replete
with helpful illustrations. He is usually careful about explaining
the specialized concepts he does introduce, presupposing only a
modest amount of knowledge.
However, clarity must be considered at two levels. Gould was a
master of the larger units—the paragraph, the article and the
book (at least the earlier books). But his sentences, especially in
later years, suffered from pathological growth. They slithered this
way and that, twisting and turning back on themselves and then
continuing on in a different direction. They lacked editorial
pruning or even the appearance of having been given a second
thought. Dawkins writes in a much more controlled and forceful way.
His sentences bear his thoughts economically and sturdily. And the
tales of his creatures are individually interesting and clear. But
the cumulative effect of quite diverse topics that are only very
loosely associated builds, if not to a decided confusion, at least
to a mild irritation and a certain disorientation.
For instance, at rendezvous 10 we find the mouse's tale, describing
the operation of the genome, and the beaver's tale, which happily
summarizes Dawkins's early book The Extended Phenotype.
When the reader reaches rendezvous 16, where the mammals and
mammal-like reptiles meet the sauropsids (which include the
dinosaurs and their living descendants, the birds), four tales are
spun out: the Galápagos finch's tale, the peacock's tale, the
dodo's tale and the elephant bird's tale. These deal, respectively,
with contemporary research on morphological divergence; sexual
selection from Darwin and Alfred Russel Wallace to Dawkins's memes;
the history of the dodo and wing loss; and finally, the breakup 150
million years ago of Gondwana (the conglomeration of several
now-separated continents and other landmasses). The overall logic of
when a tale gets told and to what species it is assigned is hardly
apparent. At times you know that Dawkins just needed some damned
creature—even a cauliflower—to hang a tale upon.
Another mark of popular science writing is a level of intimacy with
the reader. Professional books and articles usually bleed out the
personal, replacing it with layer upon layer of passively rendered
sentences and impersonal constructions. The first edition of
Darwin's Origin of Species has the first-person pronoun
sprinkled through almost every paragraph: "I think we are
driven to conclude," "I am strongly inclined to
suspect," "I may add," and so forth. By the sixth
edition, however, those "I"s have been driven out by
Darwin's growing sense of what objective science should look like.
Gould is always present in his essays and books, overbearingly so in
his later work. Dawkins's "I" makes an appearance in
virtually every tale in this book, without, however, producing any
irritation or feeling of intrusion—even when, for example, in
the midst of a discussion on the biogeography of New World monkeys,
he drops in a short disquisition on the probability of nuclear
disaster, given the limited extent of our president's intelligence.
These personal asides and observations give his book a comfortable,
inviting feeling and a quite individual cast.
Popular science books usually have a range that exceeds the
specialized research of the scientist writer. Dawkins is quick to
indicate his borrowing of ideas and theories from other
professionals. On several of the tales he lists his research
assistant Yan Wong as joint author. Dawkins's explicit references to
other authors to whom he owes a debt have the added function of
identifying some of the major contributors to contemporary
evolutionary theory.
Most popular science books, at least those written by scientists,
are built on fairly prominent sociopolitical and metaphysical
foundations. Gould's sociopolitical views wore the guise of Marxism
in a J. Press work shirt. He disdained the idea that individuals
were born with genetic chains that held them in thrall to
predetermined slots in life. Brain and consequent behavior, he
believed, revealed a flexibility that belied any of the sorts of
determinism supposed by evolutionary psychologists. Moreover,
evolutionary development, as Gould conceived it, was radically
contingent; what was done could, at any geological moment, be
undone. Thus interpretations that supposed a progressive evolution
of creatures over long periods could only be artifacts of misapplied
statistics or conservative political assumptions. Although Gould
rejected determinism from below, he did allow that larger
forces from above—for example, selection at the species
level—might shape the course of evolution, producing a gentle
sway of the atoms of life.
Dawkins's sociopolitical beliefs are fairly evident, as he takes
well-aimed shots at the current U.S. administration. In these
attitudes he seems to differ little from Gould or the majority of
liberal-minded academics, being perhaps only a bit more expressive
than most. At a deeper level, however, his metaphysical views are
quite distinct from Gould's and also from those of a large segment
of the biological community. In his disturbing book The Selfish
Gene, Dawkins portrays biological individuals as being merely
vehicles driven from below by genes fixed on their own perpetuation.
Human beings are not merely chained to their genomes, they are
hollow men whose slightest feelings, passing notions and stumbling
actions are cranked out by evolutionary machinery put in place long
ago by natural selection. Dawkins, both in that book and in this
one, certainly recognizes that phenotypes are not simply
manufactured out of individual genes alone; rather, epistatic and
environmental interactions must be part of the causal matrix
producing manifest structures and behaviors. In The Ancestor's
Tale, the genetic cogs and wheels, although they are not the
focus of attention, propel many discussions on such topics as the
way to determine phylogenetic relatedness and speciation events.
Most good popular science books and articles have a provocative, if
not a polemical, character. They don't just convey information about
scientific subjects, they argue a point of view. They urge the
adoption of the author's sociopolitical or metaphysical positions
and bring the science to support these deeper attitudes. Dawkins has
never been shy about making such arguments: They often lie
close to the surface of his writing. In this book, the very
framework of a religious pilgrimage allows him to suggest that
Darwinism offers a more reliable set of beliefs, better supported by
evidence, than the ones the Canterburians were honoring. Along the
way, he occasionally makes that suggestion more explicit. But the
most provocative feature of his book comes in the last chapter.
There the opposition is not the Biblical literalist or even the
postmodern equivalent, the Intelligent Designer; it is the shadow of
Stephen Jay Gould.
Gould liked to affirm the contingency of evolutionary development by
proposing that if the tape of evolutionary history were replayed,
the outcome would be quite different. The image is
oxymoronic—surely if the same tape were replayed, the
same outcome would be reproduced. Yet one gets his drift:
History is contingent, and even the semblance of progress would
likely disappear the second time around.
Dawkins reaches a different conclusion, although not with startling
or sterling argument. He points out that constant physical
constraints on evolutionary development—gravitation, light,
change of seasons, resources and the like—narrow the
possibilities of organic evolution considerably. Moreover, the
history of evolution shows patterns of reinvention, of convergence:
The eye has evolved independently some 40 to 60 times in
evolutionary history. This fact suggests that if the same physical
environment recurred, roughly the same sort of biological outcome
could be expected. (And of course if it were exactly the same
physical environment, then unless quantum effects played a role, you
would expect exactly the same biological outcome.) Further, that
outcome would have, according to Dawkins, progressive features
similar to those characterizing the actual history of life. The
gradual improvement in design to deal with environmental problems,
as constructed by natural selection, is, he believes, virtually the
definition of progress—at least of one clear kind. Dawkins,
however, does not probe the concept of progress much beyond that.
Neither Gould nor Dawkins seems to recognize that simply asking
whether evolution has been progressive is an ill-formed question.
One must first ask, Progressive according to what criterion? If size
is to be the criterion, one might say that generally progress was
made up to 65 million years ago, and then there was a dramatic
falling off, with a gradual rise again to the modern period. Nature
does not provide a criterion; that has to be a human choice.
Dawkins has many fascinating and instructive tales to tell, tales
that individually mark him a superb writer of popular science. Yet
great diversity, although it is the fuel for evolutionary history
itself, can be something of a liability in the description of that history.