On February 12, followers of Charles Darwin around the world will reverently celebrate his birthday, which they have christened “Darwin Day.” Known to most Americans as Abraham Lincoln’s birthday, February 12 has become for some people the secular equivalent of Christmas.

Yet British writer A.N. Wilson begins his new biography of the man with the words “Darwin was wrong.”

Darwin’s followers have been quick to react. A reviewer in the Manchester Guardian asked rhetorically “how wrong can a biography be?” A reviewer in the London Telegraph asked whether it is “the worst book about Darwin ever written.” British evolutionary biologist Steve Jones called it “the founding volume of the Fake News School of Science Writing,” and American evolutionary biologist Jerry Coyne called it “by far the worst” non-creationist book about Darwin he had ever read.

Mr. Wilson is a skilled writer, and his book is a good read. He praises Darwin for being a great naturalist; among other things, he was a world-class expert on barnacles. And Mr. Wilson’s encyclopedic knowledge of Victorian England provides a rich and fascinating context for Darwin’s life and work.

But Mr. Wilson is mistaken about some details of Darwin’s life. He writes that Darwin was “intensely ambitious” and “wanted to be cock of the walk in the world of Victorian science.” Maybe so. But to support his argument Mr. Wilson claims that Darwin cut 50 pages from one of his notebooks to avoid giving credit to a predecessor, Edward Blyth — and that the pages are still missing. Not true. Darwin simply moved the pages to another location. They were found and published years ago. On this point Mr. Wilson is wrong.

Mistakes in historical details, however, are not what infuriated Darwin’s defenders. The problem is Mr. Wilson’s irreverent attitude toward Darwin’s theory of evolution. Mr. Wilson points out that there is a difference between minor changes within existing species (“microevolution”) and the origin of new species, organs, and body plans (“macroevolution”). (One hostile reviewer claimed that this distinction is merely “a strategy of the modern creationists,” but it actually originated with evolutionary biologist Yuri Filipchenko soon after 1900.)

Although Darwin may now be revered as the Father of Evolution, people had known about microevolution for centuries. Darwin’s contribution was to propose a hypothesis about the process of macroevolution.

According to Darwin, new species originate gradually by the natural selection of small variations, as organisms better adapted to the environment survive in the struggle for existence. Although Darwin did not know the origin of variations, and although he had no evidence for natural selection, he was convinced that the process was unguided. “There seems to be no more design in the variability of organic beings, and in the action of natural selection,” he once wrote, “than in the course which the wind blows.”

Darwin called “The Origin of Species” “one long argument,” and it was a theology-laden argument against creation by design. Many people have the mistaken impression that Darwin’s theory was accepted because he provided so much scientific evidence for it (he didn’t). Instead, his theory was accepted because it fit the increasingly secular spirit of the times.

As Mr. Wilson puts it, “The whole of nature, arising from the primeval slime and evolving through its various animal forms from amoebas to the higher primates, was on a journey of improvement, moving onwards and upwards, from barnacles to shrimps, from fish to fowl, from orang-outangs to silk-hatted Members of Parliament and leaders of British industry. It was all happening without the interference or tiresome conscience-pricking of the Almighty. He, in fact, had been conveniently removed from the picture.”

More than a century later, Richard Dawkins famously wrote that “Darwin made it possible to be an intellectually fulfilled atheist.”

Mr. Wilson points out that “no other major scientific discovery or breakthrough has ‘made it possible to be an intellectually fulfilled atheist’ — only Darwin‘s. This will prompt some people to wonder whether Darwin’s distinctive twin doctrines — that evolution occurs gradually by means of natural selection, and that this process necessitates an everlasting struggle for existence — are not in fact scientific statements at all, but expressions of opinion. Metaphysical opinion at that.”

So Darwinian evolution is not so much a scientific theory as it is a secular creation myth. According to Mr. Wilson, “Darwinism, as is shown by the current state of debate, is resistant to argument because it is resistant to fact. The worship of Darwin as a man, the attribution to him of insights and discoveries which were either part of the common scientific store of knowledge or were the discoveries of others, this is all necessary to bolster the religion of Darwinism.”

Mr. Wilson’s book is not flawless, but on this point he’s right.

Jonathan Wells is a senior fellow at the Discovery Institute in Seattle and the author, most recently, of “Zombie Science” (Discovery Institute, 2017).

Published at Washington Times (January 31, 2018).