The Evolution of Evolution 99Only 6 years after returning from the Beagle voyage, Darwin had written his first sketch
of his evolutionary ideas but put it under lock and key with instructions to his wife to open
it and publish it only after his death. Darwin had good reason to be worried about his repu-
tation if he published ideas about evolution. The entire concept was associated with radical
French thinking and revolutionary politics of the lower-class medical schools in London.
It was an anathema to the powerful conservative elites of the wealthy, the nobility, and the
Anglican Church. In 1844, a Scottish publisher named Robert Chambers wrote an anony-
mous tract called Vestiges of the Natural History of Creation, which caused a national furor at its
evolutionary thinking. Although the science in Vestiges was amateurish and easy to discredit,
clearly evolutionary thinking was in the air in the 1840s. But it was still too controversial for
a respectable Cambridge-educated gentleman like Darwin to touch.
So Darwin sat on his dangerous idea for 15 years, working quietly at home on barnacles.
At that time, these animals were poorly understood, but Darwin discovered that they were
highly modified crustaceans related to shrimp, showing amazing adaptations. He published
several scientific books on barnacles, which gave him an impeccable scientific reputation.
Darwin accomplished this despite working only a few hours a day because he was wracked
by a mysterious illness, which may have been a psychosomatic response to the dangerous
ideas he was considering. All the while, he was amassing notes for a gigantic book on the
“species problem.” He would have procrastinated for many more years had he not received
a letter in the mail from a younger British naturalist, Alfred Russel Wallace, who was col-
lecting specimens in what are now Malaysia and Indonesia. During a bout of malarial fever,
Wallace had come up with a similar concept of natural selection and had sent his ideas
to Darwin, of all people. Horrified, Darwin went to his friends Charles Lyell (the famous
geologist) and Joseph Hooker (a famous botanist), searching for an honorable solution to
the dilemma of who would get credit for the idea. They arranged to have Darwin’s 1842
abstract and Wallace’s letter read at an 1858 meeting of the Linnean Society. The president
of the Linnean Society, Thomas Bell, while summarizing the discoveries for the year 1858,
wrote: “The year which has passed has not, indeed, been marked by any of those striking
discoveries which at once revolutionize, so to speak, the department of science on which
they bear.” But Darwin now had to work quickly or he would be scooped. He abandoned
his planned gigantic work and wrote a shorter (155,000 words, which was short by Victorian
standards) summary of his ideas, On the Origin of Species by Means of Natural Selection. It sold
out all 1,250 copies on the day it was published and eventually went through six editions
while Darwin was alive.
The argument of On the Origin of Species is very simple yet powerful. First, Darwin drew
an analogy to the artificial selection of domesticated animals practiced by animal breeders.
He argued that if they could modify the ancestral wolf into dogs as different as a Chihuahua
and a Great Dane, then species were not as fixed and stable as commonly believed. Then he
borrowed the idea from Malthus that natural populations are capable of exponential growth,
yet they remain stable in nature because of high mortality rates. From this he deduced that
more young are born than can survive. Darwin next described the variability of natural popula-
tions and pointed to the evidence from domesticated animals that these variations are highly
heritable. He concluded that organisms that inherit favorable variations are more likely to survive
and breed, and he called this process natural selection (called by others “survival of the fittest”).
As we saw, Darwin was not the originator of the concept of evolution, and at least two
others proposed something like natural selection. Why, then, does Darwin deserve most