July 1, 1858: Darwin and Wallace Shift the Paradigm

On July 1, 1858, the joint reading of Charles Darwin and Alfred Russel Wallace's papers on evolution to the Linnean Society occurred. From the article:

"July 1, 1858: Darwin and Wallace Shift the Paradigm

1858: The Linnaean Society of London listens to the reading of a composite paper on how natural selection accounts for the evolution and variety of species. The authors are Charles Darwin and Alfred Russel Wallace. Modern biology is born.

Scientists of the time knew that evolution occurred. The fossil record showed evidence of life forms that no longer existed. The question was, how did it occur?

Darwin had been working on his theory since 1837, soon after his epic voyage on the HMS Beagle. The hypermethodical naturalist wanted not only to classify the prodigious variation he had observed, but also to explain how it came to be.

He felt he would need to publish extensive documentation of natural selection to overcome popular resistance to so radical a notion. So he planned a comprehensive, multivolume work to convince scientists and the world.

Darwin was still working on his magnum opus when in June 1858 he received a letter from an English naturalist working in Malaysia. Alfred Russel Wallace was young and brash. When he conceived of natural selection, he didn't plan a 10-volume lifework. He just dashed off a quick paper on the subject and mailed it to the author of The Voyage of the Beagle, asking him to refer it for publication if it seemed good enough.

Darwin was crestfallen. Was he about to lose credit for two decades of work? Wallace had suggested that Darwin forward the paper to Scottish geologist Charles Lyell. Along with English botanist Joseph Hooker, Lyell was one of a small handful of people Darwin had shown early drafts of his own work on natural selection.

Darwin wrote to Lyell and Hooker, and they arranged for a joint paper to be read at the forthcoming meeting of the Linnaean Society of London. (Founded in 1788 and named for Carl Linnaeus, the Swedish scientist who devised the binomial system of taxonomy, it is the world’s oldest active biological society.)

Neither Darwin nor Wallace attended the meeting. Wallace was still in Malaysia. Darwin was at home with his wife mourning the death of their 19-month-old son just three days earlier.

1) Lyell and Hooker's own letter of introduction explaining the extraordinary circumstances;

2) An excerpt from Darwin's unpublished draft, part of a chapter titled, "On the Variation of Organic Beings in a State of Nature; on the Natural Means of Selection; on the Comparison of Domestic Races and True Species";
3) An abstract of Darwin's 1857 letter on the subject to Harvard University botanist Asa Gray;

4) Wallace's manuscript, "On the Tendency of Varieties to Depart Indefinitely From the Original Type."

The paper and the meeting did not cause an immediate sensation. Other papers were read the same day. The society had routine business to transact. The meeting was long (.pdf). But the paper was accepted for publication in the society's Proceedings later that year.

Was this a remarkable case of simultaneous discovery? Not quite. It was more like simultaneous announcement. What is remarkable is that both Darwin and Wallace credited their central insight to reading Thomas Malthus' essay, Population, first published in 1798.

Darwin read Malthus in 1838 and immediately realized how it applied to his own work. Wallace had read it around 1846, but first saw its import for explaining evolution while he lay recovering from fever in Malaysia a dozen years later.

Malthus observed that population was held in check because not every individual would survive to reproduce. As Wallace wrote, "It suddenly flashed upon me ... in every generation the inferior would inevitably be killed off and the superior would remain – that is, the fittest would survive."

But the same differences in temperament that had led to Darwin's delay and Wallace's rush to publication now worked to Darwin's advantage ... and ultimately greater fame. Wallace was already on to his next big thing: amassing huge collections of natural specimens in hopes of winning both fame and fortune.

Darwin was on to his next big thing: At the urging of his friends, he published a magnificent one-volume summary of his work, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, in 1859.

That produced an intellectual and cultural splash, perhaps the largest of the 19th century. And the sesquicentennial of the book in 2009, along with the bicentennial of Darwin's birth, was more widely marked than the 1858 event.

But our story does not end here ... quite. Both Darwin and Wallace acknowledged they did not know the precise mechanism by which the traits of the successful surviving organisms in one generation were passed on to their descendants in the next.

Two years before the Darwin-Wallace paper, an obscure Austrian monk by the name of Gregor Mendel had started work on crossbreeding varieties of peas. He discovered the patterns and importance of recombinant recessive and dominant traits. Mendel read his paper, "Experiments on Plant Hybridization," in 1865, and published it the following year.

But Mendel's work received little notice and was cited a mere three times over the next 35 years. Just as the significance of Malthus' observation had remained unnoticed until the time was ripe, so did Mendel's contribution.

Only in 1900 – in near-simultaneous publications by three different European botanists – was Mendel's work rediscovered, with its apparent application as the mechanism that had eluded Darwin and Wallace.

Sociologist Robert K. Merton postulated that "multiples" in science and invention are frequent, naming examples like the calculus, natural selection, the telegraph, the telephone and the automobile. He suggested that many more simultaneous innovations and advances go unheralded because primacy of publication or patent deters many others from being submitted to the public. Instead, researchers will seek a new and often related line of advance.

The saga of Darwin and Wallace, though, remains an extraordinary example:

•It involved not a simple invention or discovery but a paradigm shift, inventing the reigning paradigm that organizes modern biology – and in some sense all modern science.
•The work of two scientists who worked independently was announced at precisely the same date and place, in a joint paper.
•It's a multiple example of "multiples," spread across the entire globe and an entire century.

Ideas and concepts, even paradigms, come to fruition because of their social and historical milieu, as Merton and others have so aptly shown. If an idea arrives on the scene too far in advance, if the seeds are sown too early – as with Malthus and Mendel – that field may lay fallow for decades. The world of scientists is a social one of human beings whose ideas, predilections, vision and insight – as well as their blind spots and limitations – are the product of their cultures.

If it is true, in the words of Darwin contemporary Victor Hugo, that nothing is so powerful as an idea whose time has come, then perhaps it is also true that nothing is so powerless as an idea whose time has yet to come.

This article first appeared on Wired.com July 1, 2008."