Alfred Russel Wallace, the naturalist who spent eight years in Singapore and South East Asia between 1854 and 1862, discovered evolution by natural selection independently of Charles Darwin. Wallace had a dramatic eureka moment while living on the island of Ternate in the Moluccas (now Indonesia). He wrote up his ideas in an essay which he sent, incredibly, to Charles Darwin who had not yet published his own very similar theory conceived twenty years earlier. Wallace’s essay was published together with an essay by Darwin in 1858 – the first publication of the theory of evolution, which was to transform the way we think about the natural world.
As is so common in history, Wallace’s letter and essay no longer exist. Wallace’s essay was dated “February 1858” from the island of Ternate. Darwin wrote a letter to a colleague on 18 June 1858 mentioning that he had just been surprised to receive Wallace’s essay – with the amazing coincidence of the same theory. In later years Wallace often told the story of suddenly realising the idea of natural selection and sending his essay to Darwin “by the next post”. There was then only a monthly mail ship service at Ternate. So it was assumed that the essay must have been sent to Darwin in March 1858.
Why the doubts began
In 1972, a researcher named H. Lewis McKinney found another letter from Wallace to a friend named Bates that had been sent on that March 1858 steamer. The letter bore postmarks from Singapore and London showing that it had arrived in London on 3 June 1858, two weeks earlier than when Darwin had said he had received Wallace’s essay. Thus began the mystery – how could two letters from Wallace leave Ternate on the same steamer and travel along the same mail route to London with Darwin receiving his two weeks later than Bates did? This mystery led to numerous conspiracy theories with several writers claiming that Darwin stole ideas from Wallace’s essay during the time he kept the letter a secret. But other evidence suggests that Darwin received the letter when he said he did.
So did Darwin receive the letter when he said he did, or not? What could explain the discrepancy?
I decided to look into this mystery and see if anything could be found out as part of my research for the Wallace Online project and writing a book on Wallace in South East Asia. I initially assumed that it was impossible to solve this mystery since so many historians had examined it before. But it occurred to me that we really had no contemporary evidence of when Wallace sent the essay to Darwin, only his recollection, which was not that reliable a source. Hence we only assumed the letter was sent in March, but we had no actual evidence from the time. However the evidence that Darwin received it on 18 June 1858 seemed stronger, and actually dated from that time and was not a later recollection. Since that side of the correspondence was all one really had to go on, it occurred to me to trace the letter from Darwin’s end, rather than Wallace’s. If Darwin really received it on 18 June, how had it got there?
The letter had come to his house in the countryside from London the day before, the 17 June 1858. I found that a steamer had arrived in England on the 16th with mail from India and South East Asia. Well surely this was not a coincidence! Wallace’s letter must have been on that ship. I then traced the previous 9,240 miles of the journey from England, through the Mediterranean and across Egypt to Sri Lanka, Penang, Singapore, Jakarta and so on. My assistant on the Wallace Online project, Dr Kees Rookmaaker, who speaks Dutch, was an absolutely invaluable help as he was able to check the ship’s arrival and departure times in the Dutch newspapers of the time and other sources in the Dutch East Indies while I went through the English newspapers. He became as enthusiastic as I was as we closed the gaps in the letter’s itinerary. If we found any break then the whole theory would collapse.
But eventually we had the entire itinerary all the way back to Ternate. We were astonished to find that there was an unbroken series of mail connections to Ternate – not in March as all others before us had assumed, but in April 1858!
My further research shed light on why Wallace mailed his letter later than we had assumed as well as other parts of this famous, but misunderstood chapter in the history of science. Wallace sent the essay in response to a letter from Darwin, as has long been known. But that letter from Darwin only arrived on the March steamer. We conducted the first complete survey of all existing letters from Wallace in the Moluccas and none reveal that he ever replied to a letter via the same steamer on which it arrived, always on a later one. This supported the finding that the famous letter to Darwin actually connected to the April 1858 steamer.
The Wallace Online project, which will go online by 2013, the centenary of the death of Wallace, will transform our understanding of Wallace and the early exploration of biodiversity in Singapore and South East Asia. The website will contain all of Wallace’s books and articles as well as a complete collection of his published specimens collected here, a heavily revised and corrected itinerary of his travels here, his notebooks and journals edited to modern standards for the first time and much more. All available free to the world.
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