''Darwinism: An Exposition of the Theory of Natural Selection with Some of Its Applications'' is an 1889 book on

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

Alfred Russel Wallace Alfred Russel Wallace (8 January 1823 – 7 November 1913) was an English naturalist, explorer, geographer, anthropologist, biologist and illustrator. He independently conceived the theory of evolution through natural selection; his 1858 pap ...

, the co-discoverer of evolution by

natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generation ...

together with

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...

. This was a book Wallace wrote as a defensive response to the scientific critics of natural selection. Of all Wallace's books, it is cited by scholarly publications the most.

Synopsis

In ''Darwinism'' fifteen chapters,

sets out his understanding of the theory of

. He begins by defining "

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

", discussing

creationism Creationism is the faith, religious belief that nature, and aspects such as the universe, Earth, life, and humans, originated with supernatural acts of Creation myth, divine creation, and is often Pseudoscience, pseudoscientific.#Gunn 2004, Gun ...

, opinion before

, and Darwin's theory. He then describes the Malthusian struggle for existence, given the ability of organisms to reproduce in a world of finite resources. He explains the importance of variability within species, giving examples. He describes variation in domesticated animals and cultivated plants, and the process of

artificial selection Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant ...

by breeders. Wallace then explains the process of natural selection acting on pre-existing variation. He lists various issues and objections to the theory. He discusses how interspecies hybrids are usually infertile, and how this can contribute to reproductive isolation. He then examines the purpose of

animal coloration Animal coloration is the general appearance of an animal resulting from the reflection or emission of light from its surfaces. Some animals are brightly coloured, while others are hard to see. In some species, such as the peafowl, the male h ...

, including

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

and

mimicry In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. In the simples ...

, arguing that these are evidence of natural selection. He gives detailed examples of

warning coloration Aposematism is the Advertising in biology, advertising by an animal, whether terrestrial or marine, to potential predation, predators that it is not worth attacking or eating. This unprofitability may consist of any defenses which make the pr ...

and mimicry, discussing how these are produced by selection. Animal coloration and ornamentation that differs between the sexes are discussed, though he largely disagrees with Darwin's theory of

sexual selection Sexual selection is a mechanism of evolution in which members of one sex mate choice, choose mates of the other sex to mating, mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex ...

. Wallace then explores the co-evolution of flowers with their pollinators including insects and birds. He then describes the geographical distribution of organisms, arguing that this was created by long-distance dispersal of pioneer organisms, such as insects blown across the sea. He explains the geological evidence for evolution, the

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

record in successive layers of rock. He then examines objections to Darwinism concerning variation and heredity. Finally, he looks at how Darwinism may apply to humans. File:Darwinism 1889 page 219.jpg, Wallace discusses the purposes of herbivore coloration as danger and recognition

signals A signal is both the process and the result of Signal transmission, transmission of data over some transmission media, media accomplished by embedding some variation. Signals are important in multiple subject fields including signal processin ...

, with an illustration of Soemmerring's gazelle. File:Darwinism 1889 page 259 image of mimicry.jpg, Wallace discusses

Batesian mimicry Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, who worked on butt ...

with a plate of a beetle that closely mimics a wasp. File:Darwinism 1889 page 320 flowers adapted for bird pollination.jpg, Wallace discusses the

coevolution In biology, coevolution occurs when two or more species reciprocally affect each other's evolution through the process of natural selection. The term sometimes is used for two traits in the same species affecting each other's evolution, as well a ...

of flowers and pollinators, illustrating it with a bird-pollinated flower.

Analysis

In the preface to ''Darwinism'', Wallace had used the term ''pure-Darwinism'' which proposed a "greater efficacy" for natural selection. The book is notable for defending

August Weismann August Friedrich Leopold Weismann (; 17 January 18345 November 1914) was a German evolutionary biology, evolutionary biologist. Fellow German Ernst Mayr ranked him as the second most notable evolutionary theorist of the 19th century, after Charl ...

's theory of heredity and rejecting the inheritance of acquired characteristics and the concept of

which Darwin gave credence to.

George Romanes George John Romanes (20 May 1848 – 23 May 1894) was a Canadian-Scots evolutionary biologist and physiologist who laid the foundation of what he called comparative psychology, postulating a similarity of cognitive processes and mechanisms ...

dubbed this view as "Wallaceism", noting that in contrast to Darwin, this position was advocating a "pure theory of natural selection to the exclusion of any supplementary theory."Romanes, John George. (1906)
''Darwin and After Darwin: An Exposition of the Darwinian Theory and a Discussion of Post-Darwinian Questions''
Volume 2. The Open Court Publishing Company. p. 12 The book is seen as laying the foundation for the neo-Darwinian theory of evolution. Kutschera, Ulrich; Hossfeld, Uwe. (2013). ''Alfred Russel Wallace (1823–1913): the forgotten co-founder of the Neo-Darwinian theory of biological evolution''. Theory in Biosciences 132 (4): 207–214. .

References

External links

''Darwinism: An Exposition of the Theory of Natural Selection with Some of Its Applications''
Online at

Internet Archive The Internet Archive is an American 501(c)(3) organization, non-profit organization founded in 1996 by Brewster Kahle that runs a digital library website, archive.org. It provides free access to collections of digitized media including web ...

. * {{gutenberg, no=14558, name=Darwinism 1889 non-fiction books 1889 in science Books about Charles Darwin Darwinism Evolutionary biology literature

Synopsis

Analysis

References

Further reading

External links