Alfred Russel Wallace discovered the concept of evolution by natural selection.
Although he is now rarely mentioned as the discoverer (Darwin is usually cited) Wallace enjoyed a very high reputation in his lifetime, and was awarded many of the most prestigious awards in science.
He was a highly original thinker and was not afraid to court controversy. Few biologists would admit to believing that the spirits of dead people are around us, but Wallace did! He was also one of the first biologists to express concern about the effects humans were having on the natural world.
Early Life and Education
Alfred Wallace was born in Llanbadoc, Wales, 8 January, 1823. His family were middle class, but they were not well off. His father believed he was descended from William Wallace, the Scottish warrior portrayed in the movie Braveheart.
Alfred Wallace attended a grammar school: these schools did not charge fees and were attended by children who passed an academic selection test. Wallace had no formal training as a biologist and did not attend university. He trained and worked as a land surveyor, initially with his older brother’s firm.
Working outdoors, Wallace grew interested in the natural world and began collecting insects.
As his interest in insects grew, he became inspired reading about the work of naturalists such as Carl Linnaeus, Charles Darwin, and Alexander von Humboldt: these were scientists who had traveled overseas gathering samples, data, and discovering new species.
To emulate his scientific heroes, in 1848, aged 25, Wallace embarked on a voyage to Brazil with the naturalist, Henry Bates.
Wallace had little money and he intended to fund his work by collecting specimens in the Amazon for sale to British collectors and institutions. He also put his surveying skills to use, spending four years charting the course of the Rio Negro, collecting specimens, and making observations about the people and the languages he encountered along the way.
Wallace spent six years in Brazil before sailing back to the UK in 1852 with his collection of writings and specimens.
Unfortunately, the ship he was sailing on caught fire in the middle of the Atlantic Ocean. The passengers and crew abandoned ship and Wallace spent 10 days in an open boat before he was picked up. All of the specimens he had brought on the ship were lost, along with most of what he had written and drawn.
Fortunately for Wallace, he had insured the specimens, and received money for their loss.
He now worked hard, writing six papers for academic journals and two books. He also spent time meeting and getting to know other British naturalists.
2. The East Indies
The unfortunate end to his Brazilian expedition did not diminish Wallace’s thirst for travel.
In 1854, aged 31, he set off on a new voyage: to Malaysia, Singapore, Indonesia and New Guinea.
This was a much more successful expedition than Brazil, and he discovered thousands of new species of beetle. He sent over 100,000 specimens of various species back to the UK.
He also observed how between two islands – Bali and Lombok – separated by a short stretch of water there was a big change in the animal life. This is now called the Wallace Line and marks a zone where Asian wildlife meets Australian wildlife.
It was on this expedition that Wallace first described the theory of evolution.
Wallace returned to the UK from this expedition in 1862, aged 39.
The Theory of Evolution by Natural Selection
Even before he embarked on his first voyage to Brazil, Wallace was interested in evolution, writing:
I should like to take some one family [of beetles] to study thoroughly, principally with a view to the theory of the origin of species.
On his first expedition in Brazil he realized that geographical barriers often mark species boundaries.
On his second expedition in the East Indies, he suffered a tropical fever which caused him to have hallucinations. When he recovered, he found that the theory of evolution by natural selection had come to him.
As animals usually breed much more quickly than does mankind, the destruction every year from these causes must be enormous in order to keep down the numbers of each species, since evidently they do not increase regularly from year to year, as otherwise the world would long ago have been crowded with those that breed most quickly. Vaguely thinking over the enormous and constant destruction which this implied, it occurred to me to ask the question, why do some die and some live? And the answer was clearly, on the whole the best fitted live… and considering the amount of individual variation that my experience as a collector had shown me to exist, then it followed that all the changes necessary for the adaptation of the species to the changing conditions would be brought about. In this way every part of an animal’s organization could be modified exactly as required, and in the very process of this modification the unmodified would die out, and thus the definite characters and the clear isolation of each new species would be explained.
And so the theory of evolution by natural selection was born.
As part of a continuing correspondence he was having with Charles Darwin, Wallace wrote a private letter to Darwin in June 1858 with an essay containing his theory of evolution.
Some people have suggested that Darwin stole Wallace’s idea. Sir Fred Hoyle, for example, proposed that although Darwin had a huge amount of data from the natural world, he had been unable to put it together into a satisfactory formulation.
Hoyle’s proposal is not supported by the majority of biologists and historians of science. Furthermore, Wallace and Darwin became friends. It seems unlikely a friendship would have been possible if Wallace believed Darwin had behaved badly to him.
When he received Wallace’s essay, Darwin passed it to the geologist Charles Lyell and botanist Joseph Hooker, with whom he had previously discussed his own ideas of evolution by natural selection. Lyell and Hooker decided Wallace and Darwin’s theories should be read at a meeting of the Linnean Society on July 1, 1858, and, to establish Darwin’s priority, which Lyell and Hooker believed was proper, Darwin’s should be read first.
An interesting question sometimes asked is: “How long would it have taken Darwin to publish his own theory of evolution, if Wallace hadn’t sent him that essay?”
Should it be Darwin’s or Wallace’s theory of Evolution
Today we hear about Darwin’s theory of evolution. In earlier times it was often called the Darwin-Wallace theory.
In 2002, recognizing Wallace’s discovery, the evolutionary biologist Richard Dawkins said that we should be talking about the Darwin/Wallace-mechanism of natural selection.
Wallace was one of the world’s greatest biologists. He received the highest awards science could bestow, including: Royal Medal (1868), Gold Medal of the Société de Géographie (1870), Darwin Medal (1890), Founder’s Medal (1892), Linnean Medal (1892), Copley Medal (1908), Gold Darwin-Wallace Medal (1908), Order of Merit (1908).
Alfred Russel Wallace died aged 90 in Broadstone, England, 7 November, 1913. When he died, he was the most famous biologist in the world. Science historian George Beccaloni said of him:
“There were very long, glowing obituaries in all the world’s papers from Bombay to Boston saying he was the last of the great Victorians. One of the papers said only a great ruler would have had the sort of level of obituary recognition as Wallace.”
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