Driven in part by the conservative and religious character of naturalism at the time and a desire to fully hone his work, Darwin had only just begun to draft what would become The Origin of Species when Wallace’s letter arrived. 

The news shocked the great man and, after consulting with friends, he arranged for a scientific article of his own to be presented alongside one by Wallace. 

At the time, the two men shared equal billing, but the articles drew little notice. It was not until the publication of The Origin of Species the following year that Darwin would be catapulted to worldwide fame.

Huge achievements

Wallace was unusual among naturalists. He came from an ordinary background in Wales, the eighth child of nine, and was forced to withdraw from school aged 14 because of the family’s financial difficulties. 

He went on to find work as a surveyor, which led him to develop a deep interest in the natural world and pushed him to become a naturalist. He eventually self-funded a series of expeditions by selling his collected specimens.

In 1848, he headed to the Amazon Basin for four years but, during his return voyage, the ship caught fire and sank – taking almost all his samples with it. From his salvaged notes, he was still able to publish two scientific papers. 

His following expedition was to the Malay Peninsula, a journey to South East Asia, after which he wrote The Malay Archipelago. The travel book is still celebrated today and has never been out of print. 

It was on that trip that Wallace made his other great contribution to science – the discovery of the Wallace Line, which separates the flora and fauna of Asia from those of Wallacea and Australasia. 

“It was such a huge achievement really to work out what could only be proved much later by the discovery of tectonic plates,” said Dr Peter Raby, a biographer of Wallace.

Breakthrough discovery

It was also on that voyage that Wallace was struck down by malaria and made his greatest discovery. 

He had previously come close to the idea and had corresponded with Darwin, who did not suspect that Wallace was so close. It was not until his fever dreams that he had the breakthrough.

“It’s in his fever-torn dreams that it all became clear and he wrote it down, almost as though it was sort of Moses with the tablets and fired it off to Darwin, which gave Darwin a nasty shock,” Dr Raby said.

Wallace continues to be revered by modern naturalists and biologists, but his public fame is barely a patch on that of Darwin’s. 

Part of the responsibility for that may lie with Wallace’s spiritualism and insistence that evolution could not account for the human intellect.

“Wallace lost a son at a very early age and he believed that he could be in touch with him through spiritualism,” said Dr Raby. 

“That was kind of a quite a private belief, but nevertheless I think it didn’t do him much good with the harder-headed scientists.”

While Wallace was granted plenty of awards and medals, he never managed to secure a well-paid scientific posting and instead was forced to live off his writings. Darwin, however, did not forget his fellow evolutionist and in 1881 secured him a £200 per year pension.