Geoscience Reference
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plenty of biological evidence that he later used in the ground-breaking
book On the Origin of Species by Means of Natural Selection,which
appeared in the booksellers on 22 November 1859. It would not be a
wild speculation to suggest that more copies of the Bible have been
circulated than have any other printed book, but it is probable that
Origin of Species wouldoccupyaplaceinthetoptenall-timebestsellers.
Following his return to England in 1836, Darwinwrote a number
of geological topics and began to ruminate on biological ideas. Within
three years he had formulated the kernel of his theory, but he lacked
the confidence to commit his ideas to print. He was only forced to do
so over twenty years later when Alfred Russel Wallace (1823-1914)
wrote to him in June 1858 concerning his own ideas on natural selec-
tion and the formation of species. Darwin realised that both men
shared a similar vision and so together they wrote a paper that was
published by the Linnean Society in 1859 in London.
In Origin of Species Darwin proposed that new species emerged
as a result of modifications to earlier species, but that the older species
did not necessarily disappear. He argued that variation could occur
spontaneously, and that when the new species was better suited to its
environment than earlier species, natural selection had occurred. He
recognised that geographical isolation could drive speciation, and he
became interested in the mechanisms and timing of agricultural and
horticultural breeding that produced new varieties.
His conclusions drew a very mixed reaction, with many in the
Church and the scientific community outraged by what he had writ-
ten. On the other hand, he also had some supporters. In terms of
geological time and the age of the Earth, Darwin's evolutionary ideas
created a headache for many. If the elements of the fossil record were
not created by God, and were the result of progressive changes through
time, it was clear that in order to produce the great diversity of plants
and animals known from the fossil record in the way that he outlined
then an enormous span of time would be required. This time frame,
his opponents argued, was quite unrealistic.
