MISSING LINK.(Alfred Russel Wallace)(Biography)

When he was twenty-four years old, Alfred Russel Wallace, the greatest field biologist of the nineteenth century, had his head examined by a phrenologist who determined that, while his "organ of wonder" was very big, his "organ of veneration," representing respect for authority, was noticeably small. Wallace was so struck with the accuracy of this report that, sixty years later, he mentioned it in his autobiography. It was wonder that drew him to nature, and an instinctive disregard for authority that made it easy to challenge an entire civilization's religious convictions, as he did when, in 1858, he dashed off a paper proposing a theory of evolution by means of natural selection. Unlike Charles Darwin, who spent twenty years keeping a similar conclusion to himself in private dread, Wallace didn't give a damn what people thought. This utter independence from public opinion is one of several reasons that he has all but vanished from popular consciousness.

Another is simple bad luck. Wallace grew up poor and was always an outsider in the gentlemen's club that constituted the scientific world of his day. When, in his youth, he sailed to the Amazon to seek his scientific fortune, his ship caught fire and sank on the way home, taking with it thousands of specimens, a number of live monkeys, and his dream of an easy life. Wallace never found steady work and was instead forced to make a living by his pen--risky for a scientist with a restless imagination in a cautious age--supplementing his income by working as a lowly test examiner. Most unluckily of all, Wallace, having completed his explosive paper on evolution, chose to send it to Darwin himself, who then kicked into high gear and brought out "On the Origin of Species" the following year.

Still another reason for Wallace's obscurity has something to do with that phrenologist. Wallace cracked one of the greatest scientific mysteries of all time but continued to believe throughout his long life that a stranger had read the riddle of his character by feeling the bumps on his head. Phrenology was one of several commitments--like his campaign against vaccination and his credulous defense of spiritualist mediums--that did not endear him to the scientific establishment, or to posterity.

But there are signs that Wallace's time has finally come. Since 2000, at least five biographies have been published: "The Forgotten Naturalist," by John Wilson; "Alfred Russel Wallace: A Life," by Peter Raby; "In Darwin's Shadow," by Michael Shermer; "The Heretic in Darwin's Court," by Ross A. Slotten; and "An Elusive Victorian," by Martin Fichman. In addition, two recent anthologies of Wallace's own writing--"Infinite Tropics: An Alfred Russel Wallace Anthology," edited by Andrew Berry and introduced by Stephen Jay Gould; and "The Alfred Russel Wallace Reader," edited by Jane R. Camerini and introduced by David Quammen--give a sample of his consummate writing style. Joseph Conrad kept Wallace's classic "The Malay Archipelago" on his night table, drawing on it in several of his own books, most notably "Lord Jim."

G. K. Chesterton once remarked that Wallace was one of the world's great men because he led a revolution and then a counter-revolution. Having done as much as anyone to overturn traditional religious assumptions, Wallace proceeded to horrify his fellow-evolutionists by concluding that natural selection could not in itself explain the uniqueness of man. He never renounced his evolutionary theory, but instead made it the cornerstone of a theistic explanation of the universe. No wonder a later scientific generation, newly professionalized, ignored him in favor of his more austere and single-minded colleagues. But the twin impulses in Wallace's work make him compelling and oddly contemporary. He combines both halves of the debate over the meaning of evolution, coolly articulating the materialist mechanisms by which the simplest organisms morphed into human beings while arguing that our existence offers evidence of divine agency. If his name is relatively unknown, his spirit is still making itself felt nearly a hundred and fifty years after his seminal discovery.

Alfred Russel Wallace was born in Usk, Wales, in 1823, to a once prosperous family that had fallen on hard times. His father was a lawyer who never practiced, and who dabbled in doomed ...