In the eighteen-eighties, workers carving a path for Canada’s first transcontinental railway began to notice odd creatures in the rocks. A geologist working for the railway, which would run through the Kicking Horse Valley, in British Columbia, examined the rocks and was astounded. The shale of the nearby Mt. Stephen was overrun with the fossilized remains of extinct marine animals, particularly trilobites, which look like a cross between horseshoe crabs and centipedes. Word of the Mt. Stephen trilobite beds spread, and Charles Doolittle Walcott, a prominent fossil expert and the onetime director of the U.S. Geological Survey, came to investigate. In 1909, exploring north of the mountain, he found shale filled with a variety of fossils that had never been seen before.

Walcott’s discovery, called the Burgess Shale, became one of paleontology’s most important sites. The rock preserved animals in remarkable detail, in some cases including soft tissue. It contained an exceptional number of species from the Cambrian period, which began roughly five hundred and forty million years ago. The layers of Burgess Shale also added to a mystery known as the Cambrian explosion. Darwin’s theory of evolution suggests that life evolves gradually—a finch’s beak morphs over time; a wholly new bird does not suddenly appear. Yet that Cambrian layer of rock seemed to explode with new kinds of life. Darwin himself puzzled over what this might mean. If life evolved gradually, he asked in “The Origin of Species,” what would account for an explosion of it?

This question is the starting point for a new book that aims to rekindle the “intelligent design” movement. “Darwin’s Doubt,” by Stephen Meyer, which will début at No. 7 on the New York Times best-seller list this weekend, argues that scientists have found no way to account for the Cambrian explosion. Life-forms appeared with no obvious precursors, it says, too quickly for a random process of mutation and survival of the fittest to explain it. The only alternative explanation, Meyer writes, is the involvement of an intelligent designer (read: God) who rushed along the story of life on Earth.

We’ve been here before. The intelligent-design movement was born more than two decades ago, in the wreckage of creation science, and the idea is closely associated with the Discovery Institute, the Seattle think tank where Meyer works. The scientific arguments have changed over the years, but intelligent design is probably best understood as the central element of a cunning legal argument. In 1987, the Supreme Court ruled that creation science could not be taught in public schools because it was a poorly disguised version of the Bible, so the engineers of intelligent design improved the disguise: a theory that made room for the Bible without any explicit mention of the book. Advocates were thus able to argue that intelligent design should be taught in public-school biology classes. Their agenda was dealt a serious setback in 2005, when a federal judge declared that intelligent design was religion, not science, and barred it from schools.

Scientific readers will likely find that “Darwin’s Doubt” has an inspired-by-true-events feel: a few elements are recognizable, but the story makes no sense to anyone who was there. The problem for Meyer is that what has come to be called the Cambrian explosion was not, in fact, an explosion. It took place over tens of millions of years—far more time than, for example, it took humans and chimpanzees to go their separate ways. Decades of fossil discovery around the world, combined with new computer-aided analytical techniques, have given scientists a far more complete portrait of the tree of life than Darwin and Walcott had available, making connections between species that they could not see.

It turns out that many of the major gaps that Meyer identifies are the result of his misleading rearrangement of the tree. Nick Matzke, a scientist who blogs at Panda’s Thumb, makes a convincing case that Meyer does not understand the field’s key statistical techniques (among other things). For example, Meyer presents a chart on page thirty-five of “Darwin’s Doubt” that appears to show the sudden appearance of large numbers of major animal groups in the Cambrian: the smoking gun. But if one looks at a family tree based on current science, it looks nothing like Meyer’s, and precisely like what Darwinian theory would predict. “All of this is pretty good evidence for the basic idea that the Cambrian ‘Explosion’ is really the radiation of simple bilaterian worms into more complex worms…[which] occurred in many stages, instead of all at once,” Matzke writes.

Meyer goes on to build a grander, more bizarre argument that draws from the intelligent-design well. The genetic machinery of life, he writes, is incapable of grand leaps forward, meaning that any dramatic biological innovation must be the work of the intelligent designer. Yet scientific literature contains many well-documented counterexamples to Meyer’s argument, and the mechanisms by which life’s machinery can change quickly are well known. Whole genes can be duplicated, for example, and the copy can evolve new functions.

Most absurd of all is the book’s stance on knowledge: if something cannot be fully explained by today’s science—and there is plenty about the Cambrian, and the universe, that cannot—then we should assume it is fundamentally beyond explanation, and therefore the work of a supreme deity.

But do not underestimate “Darwin’s Doubt”: it is a masterwork of pseudoscience. Meyer is a reasonably fluid writer who weaves anecdote and patient explanation. He skillfully deploys the trappings of science—the journals, the conferences, the Latinate terminology. He has a Ph.D. from the University of Cambridge in the philosophy of science. He appears serious and, above all, reasonable. The Cambrian argument has been a part of creationism and its inheritors for many years, but Meyer’s project is to canonize it, a task he completes with great skill. Those who feel a hunger for material evidence of God or who sense that science is a conspiracy against spiritual meaning will find the book a thrilling read. Which is to say, Meyer will find a large audience: he aims to start a conversation, or to at least keep one going, and he seems likely to succeed.

The book’s best, most honest moments come in the concluding chapter, in which Meyer travels to see the famous Burgess Shale in person. His son goes ahead on the trail but then suddenly freezes, stricken with vertigo after peering down the mountainside. Meyer likens his son’s paralysis to modernity’s despair at materialism, its shock at the prospect that the universe is utterly indifferent. Meyer writes frankly, saying that his quest is to give people back their sense of meaning and purpose. Here, at last, Meyer is not pretending to be a scientist.