The Accidental Species: Misunderstandings of Human Evolution (19 page)

First impressions can save your life—or tell you lies.

So, while we are very good at recognizing objects, our talent is so refined that we are inclined to see patterns where there aren’t any. Almost everyone who looks at the surface of the moon sees a human face, even though we know quite well that the features responsible for the illusion are in fact gigantic plains of ancient lava, and nothing to do with faces at all. We are perfectly aware of our tendency to make nonexistent connections, to spot nonexistent patterns. In such error lies much of importance and interest in our cultural heritage, in images of all kinds from classical trompe l’oeil to surrealism, in the comedies of errors in Shakespeare’s plays and Mozart’s operas to the cheapest farces, and in just about every joke you can think of. Here is an example (I have better ones, but they are too rude for a family audience).

A: I say, I say, I say, how do you tell the difference between a postbox and the back end of a cow?

B: I don’t know, how
do
you tell the difference between a postbox and the back end of a cow?

A: Well, if you don’t know the answer to that, I won’t send
you
to post the letters.

“Ba-boom,” and, moreover, “tish.”

So, much as we might indulge children who see elephants and rail
way trains in passing clouds, not to mention scoff at people who see images of Jesus in pieces of toast, everyone is at it—even scientists. One immediately brings to mind the story of the Italian astronomer Schiaparelli, who unwittingly joined the barely visible dots of craters on distant Mars into “channels” or, in Italian,
canali
—an illusion (compounded by mistranslation) that led American astronomer Percival Lowell to posit the existence of a globe-spanning system of canals, moving quantities of water from the martian poles, dug by a technologically advanced civilization under threat of extinction by drought. From this very human error comes H. G. Wells’s stirring tale of Earth’s invasion by Mars in
The War of the Worlds
; Orson Welles’s notorious radio adaptation that had terrified crowds flocking into the streets, watching the sky; Edgar Rice Burroughs’s Barsoom fantasies; and much else. Even today, when we know perfectly well that John Carter of Mars is a character in a pulp fantasy, and that tripods squirting death rays are unlikely to be found in New Jersey, nor, as it may be, suburban Surrey, scientists with their intellects vast, overheated, and oversympathetic look at Mars with eyes perhaps overwelcoming of the possibility of life.

All of which areological digression leads me very conveniently to another remarkable ability of humans—that of telling stories. Chains of unconnected craters became lines which became canals which became, implicitly, a heroic narrative of a great civilization struggling against extinction—and, more explicitly, thrilling yarns of interplanetary warfare and high adventure.

So, not only are we good at spotting patterns, even if nonexistent ones, we tend to weave them into tales as ways of making sense of what might otherwise be sets of disconnected and therefore worrying phenomena. This ability is so ingrained that it even haunts our subconscious. Things that go bump in the night are seamlessly woven into the stories we tell ourselves in dreams. It is easy to see how our ancestors, living much closer to nature, the unknown, and the reality of sudden and unexplained phenomena than we do nowadays, would hear thunder in the mountains and console themselves with stories of angry gods. And because telling stories is what we do, even without conscious intervention, it’s easy to underestimate how the power of narrative undermines our efforts to make sense of the past, in any clear, cool, or rational way.

Fossils present direct evidence of the prehistoric past and for evolutionary change, but they are very thin gruel on which to build a
narrative—rather like the dots of individual craters that Schiaparelli and Lowell willed into line segments, canals, and stories. This has not stopped people doing that very thing, but if they do, they must be aware that such a narrative is very likely to be colored as much by past prejudices as by present evidence. Fossils don’t tell stories.
We
tell stories.

And so, in popular science books, particularly older ones, you’ll hear tales of the ages of life—the Age of Fishes, the Age of Amphibians, the Age of Reptiles, the Age of Mammals, just as if they were biblical dynasties, one succeeding the other, replacing the one before—inevitable, seamless, majestic, culminating in the Age of Man.

One of my favorite examples of this tendency is indeed called
The Age of Reptiles
. This is a marvelous 110-foot mural at the Peabody Museum of Natural History at Yale, painted in 1947 by Rudolph F. Zallinger. It depicts almost 350 million years of prehistory as a landscape, with time moving from left to right. This image—and the various dinosaurs and other animals pictured within it—has become iconic.

Even before I knew what a dinosaur was, I knew of Zallinger’s work. For my fifth birthday I was given a book called
Wonders of Nature
, whose back cover was adorned with a kind of condensed version of
The Age of Reptiles
. I still have the book (I’m looking at it as I write this), and there is no indication of what the animals on the back cover were—no caption, no acknowledgment, no nothing. But I was captivated, nonetheless.

A little later when I was at school, I loved the Life Nature Library, a series of color primers on science brought out by Time-Life. It was in the book called
Early Man
(1965) that I first came across the now canonical image of human ancestry, depicted as a left-to-right “march” of ancestry and descent, the conceptual progenitor of my
figures 1
and
2
earlier in this book, and of many others. The picture was called
The March of Progress
and was painted—hey, you’re way ahead of me—by Rudolph Zallinger. I do not think Zallinger had any intention to mislead. He did not, after all, draw arrows between the various reconstructed hominins. But his images have the power they do because they trigger our innate desire for narrative. Once we see them, we cannot help but put arrows between the images and think of them as ancestors and descendants.

In this book, therefore, I have as much hope of curing you of a perfectly natural desire to make stories out of disconnected dots as per
suading the tide to turn at my command. All I can do is show you how very hard it is, in reality, to justify evolutionary narratives created from fossil evidence; invite you to wonder why it is that you create the stories you do; ask you to inquire how your status as a human being colors your view (quite naturally) of what you think ought to have happened; and, once that has been accounted for, imagine what other stories might be possible given the evidence at hand.

What would our picture of human evolution be like had we evidence of many more kinds of fossil hominin living into the recent past, or fewer; or had we persuasive evidence of nonhuman hominins living on this planet today?

The irony is that—I guess—our picture of evolution would be very similar to the one we have now. Such are our prejudices about progress; such is our overwhelming need to tell stories, that we’d have spun a tale of upward progress and improvement, culminating in Man, no matter whether we had ten times the fossils we have now, or none, and irrespective of the provenance or the poverty of the ingredients.

At this point I should add a few cautionary paragraphs. I made similar points in my book
In Search of Deep Time
(1999), but my words continue to be misconstrued more than a decade later—quite willfully and deliberately, and with intention to deceive. The culprits have been creationists, who quote extensively from
In Search of Deep Time
in support of their view that evolution is somehow “wrong,” such that even a “prominent evolutionary biologist” such as myself “admits” this. Despite repeated attempts to expose creationists for such context-free quote-mining, the creationists are still at it.

Perhaps the most shameful activity in which creationists indulge is to present a distorted version of science to parishioners who might not know any better. A few years ago an elderly neighbor came up to Mrs. Gee in the street and gave her a pamphlet that she thought might be interesting, as it mentioned me. I sighed—it was Christian literature in which my various utterances on evolution had been quote-mined in support of creationism. Readers in the United States, who are more used to this sort of thing, will be either comforted or disturbed to learn that creationism runs deep in mainstream English churchgoers, not to mention synagoguegoers and mosquegoers.

It is quite true that I have said quite a few grandstanding things about evolution, and if taken out of context, you can see why they fill
creationists with glee. Here is a choice selection from
In Search of Deep Time
, extracted and presented out of context by a creationist website,
¹
with responses by me.

The intervals of time that separate fossils are so huge that we cannot say anything definite about their possible connection through ancestry and descent.

Leaving aside the assertion by some creationists that no such intervals of time exist, the creationist spin is that no connection exists between ancestors and descendants, because of the unsupported presumption that God made everything separately. The proper answer (made clear elsewhere) is that ancestors and descendants exist—the community of all life is evidence for this—but we could never know that any fossil we find is an ancestor or descendant or anything else. Quite apart from anything else, the concept of Darwinian evolution is more elegant as a theory than anything offered by creationism, because it explains the community of all life without recourse to any other factors, whether they are Lamarckian
besoin
, Goethean cosmic strivings, or God.

New fossil discoveries are fitted into this preexisting story. We call these new discoveries “missing links,” as if the chain of ancestry and descent were a real object for our contemplation, and not what it really is: a completely human invention created after the fact, shaped to accord with human prejudices. In reality, the physical record of human evolution is more modest. Each fossil represents an isolated point, with no knowable connection to any other given fossil, and all float around in an overwhelming sea of gaps.

Dinosaurs are fossils, and, like all fossils, they are isolated tableaux illuminating the measureless corridor of Deep Time. To recall what I said in chapter 1, no fossil is buried with its birth certificate. That, and the scarcity of fossils, means that it is effectively impossible to link fossils into chains of cause and effect in any valid way, whether we are talking about the extinction of the dinosaurs, or chains of ancestry and descent. Everything we think we know about the causal relations of events in Deep Time has been invented by us, after the fact.

To take a line of fossils and claim that they represent a lineage is not a scientific hypothesis that can be tested, but an assertion that carries
the same validity as a bedtime story—amusing, perhaps even instructive, but not scientific.

The chain of ancestry and descent we construct after the fact is just that—a human construction, a way of interpreting the evidence. However, this does not negate the existence of evolutionary ancestry and descent. I suspect creationists are sometimes motivated by the suggestion that when evolutionary biologists are in company, away from the public eye, they “admit” that evolution is wrong, while perpetuating some enormous cover-up to set before the masses. One shouldn’t like to say in print that this is paranoid, but any suspicion of such a cover-up is immediately scotched by the fact that many books making these points are widely available to the public.
In Search of Deep Time
was hardly a massive best seller—but it wasn’t some dark secret either, the existence of which could only be vouchsafed to the Elect.

All the evidence for the hominid lineage between about 10 and 5 million years ago—several thousand generations of living creatures—can be fitted into a small box.

To which we say—so what? This illustrates the extreme poverty of the fossil record, offering a caution to anyone who would use this evidence on which to base an evolutionary scenario. It doesn’t dent evolution in any way.

Creationists quote material out of context to give you the misleading impression that anyone has any doubt about evolution’s status as a theory so well worn that it can be accepted as true. I hold that view now, just as I did more than ten years ago when I wrote
In Search of Deep Time
—and in that book, too, I made my views clear, except that creationists have chosen not to mention them. “If it is fair to assume that all life on Earth shares a common evolutionary origin,” I wrote on page 5, going on to make clear that this is my assumption throughout the book. Creationists are very good at either ignoring such statements—or, if they mention them, say words to the effect that if even “prominent evolutionists” who explicitly sign up to the fact of evolution can produce statements in which evolution is doubted, there shouldn’t be any reason for anyone else to “believe” in evolution, either. And they just keep rolling along: enter “Henry Gee” and “creationism” into a search engine of your choice, and they’ll be all over you like
an embarrassing rash. That said, I have had some robust and heartening support.
²

The sad thing is that no matter how hard I fight, the creationists will still take quotes out of context, because that’s the way they do what they call “science.” Like all pseudoscientists and peddlers of charlatanry, they don’t investigate anything systematically. They just pick out the things they like and discard anything else, even flat statements to the contrary. Now, I could try quoting scripture out of context to show how such a procedure can be used to mislead. For example, “There is no God.”
³
But that approach might be too subtle. That said, I refuse to modify my thoughts for fear of being quote-mined by idiots. I tend to regard creationists as an occupational hazard, rather in the same way that those who go walking in the dark, looking up at the stars, will occasionally tread in a pile of dog shit.