Biology Reference
In-Depth Information
cannot afford to buy it. This situation may well change in the future, as a result of
the effects of climate change on agriculture.
At least two other people had previously published the idea of natural selec-
tion before Darwin, such as William Wells in 1818 and Patrick Matthew in 1831.
Matthew even used the term “the natural law of selection” but his work was not
widely known, and Darwin did not come across it until after the first edition of
On
the Origin of Species
was published in 1859. In the Historical Sketch that Darwin
added to the third edition of his topic, Darwin lists Matthew among thirty-four
authors who had previously published similar ideas. By 1844, Darwin had com-
pleted the first draft of his ideas on natural selection in the form of an essay of 239
pages, but fearful of the controversy these ideas might arouse at such a turbulent
time in European history, he placed it in the hall cupboard at Down House, with
a note saying that the contents should be published only in the event of his death.
When visiting Down House in 2008, I came across a replica of this package, placed
in the hall cupboard by English Heritage, who have restored the house and garden
to its state in Darwin's time.
Darwin was a prolific letter writer, and corresponded with many people about
biological matters. One of these people was Alfred Russel Wallace, a prominent
naturalist who published a popular book about the plants and animals of the Malay
Archipelago. Wallace was the leading expert on the distribution of animal species
in the nineteenth century, and has been called “the father of biogeography”. Like
Darwin, he also was greatly influenced by reading the essay on population growth by
Malthus. In 1858, Darwin was shocked to receive an essay from Wallace, outlining
ideas about natural selection closely similar to his own. Realising that he might be
scooped, Darwin sent the essay, together with one of his own, to scientific friends
in London, who arranged that both papers were read in the absence of their authors
at a meeting of the Linnean Society on July 1st, and subsequently published. This
unexpected development spurred Darwin to write
On the Origin of Species,
which
appeared the following year. Wallace later acknowledged that Darwin had the idea
of natural selection before him, and had amassed much more evidence in support.
Wallace famously called Darwin “the Newton of Natural History” because he had
unified biology with a universally applicable idea, just as Newton unified the physics
of his time with his theory of gravity.
This story tells us something about what motivates scientists. As well as the urge
to understand the world, each scientist feels the need to be thought well of by fellow
scientists, and to achieve this they are keen to publish new ideas and discoveries as
soon as possible in order to claim priority. So science is not the disinterested pursuit
of truth that it is often portrayed to be - scientists are human, and have egos like
everybody else! The same motivation is, of course, present in enthusiasts in other
fields, such as literature, music and the theatre.
By 1870, the fact that evolution had occurred was generally accepted among biol-
ogists, but the suggested mechanism of natural selection was not generally accepted
until the 1930s, some 60 years later. The reason was that Darwin was unable to
explain how the variation among individuals was generated, or how this variation
was passed onto the next generation - he had no theory of heredity. It is one of the
great “Ifs” of history to wonders how the subject would have developed if Darwin
