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Charles Darwin: The Origin of Species (1859) Opposition to evolutionary theory
has always been most vigorous among those who felt that their religious
beliefs required them to reject it. Darwin was acutely aware of this fact and
tried whenever he could to accommodate religious sensibilities. In the
following overview of his theory of natural selection he emphasizes not only
how much more rational the theory is than the claim
that each species was separately created, but argues that it is marvelous and
worthy of a majestic creator as well. In the final paragraph he lays down the
basic elements of his theory: that individuals in every species tend
naturally to vary from the norm, and that when there are so many members of a
species sharing an ecological niche that they are competing for survival,
only those who whose variations give them decisive advantages will survive.
They will pass these characteristics on to their descendants. Despite many
disagreements among scientists about the details of evolution, some of which
are mentioned in the footnotes below, most of them agree that a century and a
half of accumulated evidence supports the broad outlines of this elegant
theory which explains nature's oddities, failures and even occasional
ugliness as the products of chance operations rather than of an omnipotent
god. What examples does Darwin give of
features of nature that seem like errors ("less than perfect")? As
natural selection acts solely by accumulating slight, successive, favorable
variations, it can produce no great or sudden modifications; it can act only
by short and slow steps. (1) Hence, the canon of "Natura non facit saltum," (2) which every fresh addition to our
knowledge tends to confirm, is on this theory intelligible. We can see why
throughout nature the same general end is gained by an almost infinite
diversity of means, for every peculiarity when once acquired is long
inherited, and structures already modified in many different ways have to be
adapted for the same general purpose. We can, in short, see why nature is
prodigal in variety, though niggard
(3) in innovation. But why this should be a law of nature if each species
has been independently created no man can explain. Many
other facts are, as it seems to me, explicable on this theory. How strange it
is that a bird, under the form of a woodpecker, should prey on insects on the
ground; that upland geese which rarely or never swim, should possess webbed
feet; that a thrush-like bird should dive and feed on sub-aquatic insects;
and that a petrel should have the habits and structure fitting it for the
life of an auk! and so in endless other cases. But
on the view of each species constantly trying to increase in member, with
natural selection always ready to adapt the slowly varying descendants of
each to any unoccupied or ill-occupied place in nature, these facts cease to
be strange, or might even have been anticipated. We can
to a certain extent understand how it is that there is so much beauty
throughout nature; for this may be largely attributed to the agency of
selection. That beauty, according to our sense of it, is not universal, must
be admitted by every one who will look at some
venomous snakes, at some fishes, and at certain hideous bats with a distorted
resemblance to the human face. Sexual selection has given the most brilliant
colors, elegant patterns, and other ornaments to the males, and sometimes to
both sexes of many birds, butterflies, and other animals. With birds it has
often rendered the voice of the male musical to the female, as well as to our
ears. Flowers and fruit have been rendered conspicuous by brilliant colors in
contrast with the green foliage, in order that the flowers may be easily
seen, visited, and fertilized by insects, and the seeds disseminated by
birds. How it comes that certain colors, sounds, and forms should give
pleasure to man and the lower animals,--that is, how the sense of beauty in
its simplest form was first acquired,--we do not know any more than how
certain odors and favors were first rendered agreeable. As
natural selection acts by competition, it adapts and improves the inhabitants
of each country only in relation to their co-inhabitants; so that we need
feel no surprise at the species of any one country, although on the ordinary
view supposed to have been created and specially adapted for that country,
being beaten and supplanted by the naturalized productions from another land.
Nor ought we to marvel if all the contrivances in nature be
not, as far as we can judge, absolutely perfect, as in the case even of the
human eye; or if some of them be abhorrent to our ideas of fitness. We need
not marvel at the sting of the bee, when used against an enemy, causing the
bee's own death; at drones being produced in such great numbers for one
single act, and being then slaughtered by their sterile sisters; at the
astonishing waste of pollen by our fir-trees; at the instinctive hatred of
the queen-bee for her own fertile daughters; at ichneumonidae (4) feeding within the living bodies of
caterpillars; or at other such cases. The wonder indeed is, on the theory of
natural selection, that more cases of the want
(5) of absolute perfection have not been detected. . . . Authors
of the highest eminence seem to be fully satisfied with the view that each
species has been independently created. To my mind it accords better with
what we know of the laws impressed on matter by the Creator,
that the production and extinction of the past and present inhabitants
of the world should have been due to secondary causes, like those determining
the birth and death of the individual. When I view all beings not as special
creations, but as the lineal descendants of some few beings which lived long
before the first bed of the Cambrian
(6) system was deposited, they seem to me to become ennobled. Judging
from the past, we may safely infer that not one living species will transmit
its unaltered likeness to a distant futurity. And of the species now living
very few will transmit progeny of any kind to a far distant futurity; for the
manner in which all organic beings are grouped, shows that the greater number
of species in each genus, and all the species in many genera, have left no
descendants, but have become utterly extinct. We can so far take a prophetic
glance into futurity as to foretell that it will be the common and
widely-spread species, belonging to the larger and dominant groups within
each class, which will ultimately prevail and procreate new and dominant
species. As all the living forms of life are the lineal descendants of those
which lived long before the Cambrian epoch, we may feel certain that the
ordinary succession by generation has never once been broken, and that no
cataclysm has desolated the whole world. (7) Hence we may look with some
confidence to a secure future of great length. And as natural selection works
solely by and for the good of each being, all
corporeal and mental endowments will tend to progress towards perfection. (8) It is
interesting to contemplate a tangled bank, clothed with many plants of many
kinds, with birds singing on the bushes, with various insects flitting about,
and with worms crawling through the damp earth, and to reflect that these
elaborately constructed forms, so different from each other, and dependent
upon each other in so complex a manner, have all been produced by laws acting
around us. These laws, taken in the largest sense, being Growth with
Reproduction; Inheritance which is almost implied by reproduction;
Variability from the indirect and direct action of the conditions of life,
and from use and disuse: a Ratio of Increase so high as to lead to a Struggle
for Life, and as a consequence to Natural Selection, entailing Divergence of
Character and the Extinction of less-improved forms. Thus, from the war of
nature, from famine and death, the most exalted object which we are capable
of conceiving, namely, the production of the higher animals, directly
follows. There is grandeur in this view of life, with its several powers,
having been originally breathed by the Creator into a few forms or into one;
and that, whilst this planet has gone cycling on according to the fixed law
of gravity, from so simple a beginning endless forms most beautiful and most
wonderful have been, and are being evolved. (1) One modern school of thought rejects Darwin's
gradualism, arguing that sudden and widespread change after long periods of
stability has been more characteristic of evolutionary history. (2) Nature makes no leaps. (3) Miserly. (4) A kind of wasp. (5) Lack. (6) About 700,000,000 years ago (7) Darwin has in mind not only
the Biblical flood, but theories of nature which attributed all traces of
large-scale change to various catastrophes. Ironically, most modern
Darwinians have integrated the belief in at least one great cataclysm--the cometary impact which evidently ended the age of the
dinosaurs--into evolutionary theory. (8) This view has been disputed by
some scientists who argue that later forms are not necessarily
"better" than later ones. The Complete
Text of The Origin of Species |