This year is the centenary of the death of Victorian naturalist and co-discoverer of evolution by natural selection, Alfred Russel Wallace. So we have heard a lot about him recently, including the BBC Two series Bill Bailey's Jungle Hero, an episode of BBC Radio 4's In Our Time, two episodes of The Infinite Monkey Cage and scores of articles, talks and exhibitions.

Wallace deserves more attention but much of what you will have heard about him in the last few months is factually incorrect – and amounts to a misguided campaign to reinstate the reputation of a genius who (according to his fans) has been wronged by history and robbed of his rightful fame.

Since the 1970s, the story of Wallace has become something like this:

While Charles Darwin sat on his revolutionary theory for 20 years, terrified of his conservative contemporaries, Wallace boldly set out to solve the great problem of the origin of species. Not afraid to announce unorthodox views, Wallace published a radically innovative theory of evolution (minus only natural selection) in an 1855 paper.

Then, while on the island of Gilolo and prompted by thoughts about the local races, Wallace hit on the idea of the struggle for existence and natural selection. He immediately wrote up his theory and posted it to Darwin on the next mail steamer.

Darwin, however, withheld the paper for perhaps two weeks before he let it become known. During this time, according to some, Darwin stole some ideas to use in his own otherwise identical theory.

Rather than having Wallace's paper published immediately on its own, which was normal practice at the time, Darwin's friends cooked up a scheme to rob the working-class Wallace of his priority and instead put their friend Darwin first. Papers by both men were read at a scientific meeting in 1858, but Darwin is remembered as the discoverer of the theory because his contribution was placed first.

Swept under the carpet of history

The new shelf of sympathetically written books about Wallace tells a pretty consistent story. He is now "forgotten" because he has been unfairly swept under the carpet of history. Why? Because the wealthy and privileged Darwin basks in all the glory of revolutionising our understanding of life on Earth. (Not to mention the back of the £10 note, although Jane Austen is about to boot him off that pedestal).

Darwin's life and works have been meticulously studied by many scholars for over a century. But while some very able scholars have studied Wallace, he by contrast has remained mostly the preserve of amateurs and enthusiasts.

There has not been enough progress with our understanding of Wallace because some of the important research projects that have unveiled a treasure trove of new findings about Darwin had never been done for Wallace: his complete works had not been assembled on one scholarly website, his Malay archipelago expedition correspondence had not been collected and edited and his notebooks and journals had not been edited and their contents made intelligible.

All of these have recently been done, the latter two not yet published. These new sources have shown us that every substantive claim in the popular narrative about Wallace turns out to be incorrect.

• Wallace was not working class but the son of a gentleman and attended a public school.

• He thought of natural selection on the island of Ternate, not Gilolo. Hence the races there did not inspire his theory.

• He did not send his essay to Darwin on the next steamer, but replied on the following monthly steamer. So Darwin received Wallace's essay exactly when he said he did.

• Darwin and his friends were not obliged to publish Wallace's paper, as he had not requested this, but it was acceptable practice at the time for Wallace's essay to be published without seeking his explicit permission first.

• Darwin did not borrow any idea on evolutionary divergence from Wallace - who in fact had no such theory of his own. And in any case, at the time scientific priority was not settled only by publication, but also by sharing one's views with colleagues privately.

• Darwin did not keep his belief in evolution secret and he did not postpone publishing because of any fears. But ironically Wallace was afraid to reveal his evolutionary beliefs and carefully concealed them in his published papers. His famous 1855 paper never mentions evolution.

What inspired Wallace's eureka moment?

Wallace's notebooks reveal the gradual development of most of his evolutionary ideas. Far from the story that he set out to discover a mechanism for evolution, Wallace showed no interest in the causes of adaptations. On the contrary, he privately ridiculed traditional ideas of adaptation as evidence of divine design.

All this makes his essay proposing natural selection all the more mysterious. For Darwin we have a detailed paper trail revealing the development of his conception of natural selection. For Wallace we only have his published essay. What inspired Wallace's famous eureka moment in the midst of a malarial fever?

There is only one contemporary clue. In a letter written about two weeks later, Wallace mentioned that over the past four years he had found differently coloured tiger beetles on different islands which exactly matched the colour of the sand or mud where they lived. "Such facts as these puzzled me for a long time, but I have lately worked out a theory which accounts for them naturally."

Wallace already believed that new varieties of animals appeared randomly and frequently, the offspring of their parent species. If lots of varieties of various shades are constantly appearing, how does one come to perfectly match the colour of the environment? He remembered the idea of the struggle for existence. The varieties best suited to survive would be those that happened to be the right colour.

If the environment slowly changed colour, the parent species might go extinct. One of its daughter varieties could then be well adapted and replace it as the species. It could never revert back to the colour of its parent as that was now inferior. Thus through a struggle for existence, randomly generated variants would be sifted to form new species. It was a brilliant breakthrough.

But the real story of Wallace's contribution is far from the myth of the wronged working class hero. The differences between the Wallace of his modern admirers and the historical Wallace are in fact like the differences between the Jesus of pious Christians and the historical Jesus.

Darwin gained nothing from having his paper printed ahead of Wallace's. Darwin's fame and reputation, and Wallace's comparative obscurity, stem from the impact of Darwin's Origin of Species. As Wallace himself wrote: "this vast, this totally unprecedented change in public opinion has been the result of the work of one man, and was brought about in the short space of twenty years!"

Dr John van Wyhe is a historian of science at the National University of Singapore and director of Darwin Online and Wallace Online. His book Dispelling the Darkness: Voyage in the Malay Archipelago and the Discovery of Evolution by Wallace and Darwin is published this month