Summary
Darwin begins by explaining how he formed his theory of
natural selection. As a naturalist aboard the H.M.S. Beagle (1831–1836), he
observed, and recorded data on, the various species in South America
and its neighboring islands. These observations led him to think
more about the mystery of the origin of species, and upon his return
to Great Britain in 1837, he started sketching
out his theory. He had been working on synthesizing the arguments
in his manuscript since that time. Although his work was not quite
done, Darwin explains that two factors were forcing him to publish
this abstract of his theory now: his failing health and the fact
that naturalist Alfred Russel Wallace had come near to discovering
the very theory that Darwin had been working to complete. Darwin
recognized that subsequent publications would be necessary to fill
in the details missing from the conclusions he draws here.
Darwin also notes that he is certainly not the first naturalist
to observe similarities between organic species and conclude that
species were not been created independently, but rather descended from
one another. However, while contemporary naturalists assumed that
external conditions, such as climate and food, are the sole cause
of variation in species, Darwin argues that something more than
the environment must be at work in creating beings so perfect in
their structure and ability to adapt. While the anonymous author
of Vestiges of Creation presents a theory of descent,
he fails to account for the remarkable co-adaptation of beings to
one another and to their specific physical conditions. Darwin argues that
his theory, developed by a careful study of domesticated animals
and cultivated plants, as well as natural organisms, will provide
a better explanation for the origin of species.
Finally, Darwin provides an overview of the arguments
in his origin theory. He previews the concept of natural selection,
which states that beings with advantageous variations will be “naturally selected”
over others and have the best chance of survival. He argues that
his theory will shed light not only on the origin of species but
also on the future successes and modifications of all the earth’s inhabitants.
Species, he argues, are susceptible to change, and it is natural
selection that causes these changes to occur.
Analysis
In the introduction, Darwin introduces a few of his recurring themes.
Foremost among them is the importance of using scientific reasoning
to understand nature. Darwin is careful to phrase his methodology
in terms of scientific experimentation. He grounds his theory in
the two key principles of scientific research: experimentation and
observation. He argues that the origin of species can be understood
only through careful observation, the kind he did aboard the H.M.S. Beagle and
later in his study of domesticated plants and animals. Darwin’s
research method relies on inductive reasoning,
which means the use of specific examples to draw broader conclusions.
Implicitly, this research method gives authority to science and
its power of knowledge and discovery.
Although Darwin applauds scientific methodology, he also
hints at the uncertainties that plague scientific discovery. The
tension between scientific authority and scientific uncertainty
comes up often in Darwin’s writings. His awareness of the theoretical
nature of his natural selection argument prevents him from presenting
his theory with total confidence. By expressing doubt about the
completeness of his own theory, Darwin allows us to question his
conclusions. And by expressing doubt about other people’s scientific theories,
Darwin admits to the uncertainty inherent in any scientific theory
or process. Although science, according to Darwin, has the power
to discover the origin of species, this power will never be absolute.
Another pioneering scientist named Alfred Russel Wallace devised
his own theory of evolution, which closely resembles Darwin’s. This
coexisting theory, outlined in Wallace’s essay On the Tendency
of Varieties to Depart Indefinitely From the Original Type, prompted
one of the main controversies surrounding Darwin’s work and consequent
celebrity. Because Darwin had read Wallace’s manuscript prior to
publishing the Origin of Species, many accused
him of stealing Wallace’s theory. Darwin was urged to rush his findings
into publication to beat Wallace to the punch and, as a result,
received the credit from the scientific community for the theory
of natural selection.