On the Origin of Species in the context of "Fantail pigeon"

Evolution is the change in the heritable characteristics of biological populations over successive generations. It occurs when evolutionary processes such as genetic drift and natural selection act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. The process of evolution has given rise to biodiversity at every level of biological organisation.

The scientific theory of evolution by natural selection was conceived independently by two British naturalists, Charles Darwin and Alfred Russel Wallace, in the mid-19th century as an explanation for why organisms are adapted to their physical and biological environments. The theory was first set out in detail in Darwin's book On the Origin of Species. Evolution by natural selection is established by observable facts about living organisms: (1) more offspring are often produced than can possibly survive; (2) traits vary among individuals with respect to their morphology, physiology, and behaviour; (3) different traits confer different rates of survival and reproduction (differential fitness); and (4) traits can be passed from generation to generation (heritability of fitness). In successive generations, members of a population are therefore more likely to be replaced by the offspring of parents with favourable characteristics for that environment.

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 paper on the subject was published that year alongside extracts from Charles Darwin's writings on the topic. It spurred Darwin to set aside the "big species book" he was drafting and to quickly write an abstract of it, which was published in 1859 as On the Origin of Species.

Wallace did extensive fieldwork, starting in the Amazon River basin. He then did fieldwork in the Malay Archipelago, where he identified the faunal divide now termed the Wallace Line, which separates the Indonesian archipelago into two distinct parts: a western portion in which the animals are largely of Asian origin, and an eastern portion where the fauna reflect Australasia. He was considered the 19th century's leading expert on the geographical distribution of animal species, and is sometimes called the "father of biogeography", or more specifically of zoogeography.

The 19th century in science saw the birth of science as a profession; the term scientist was coined in 1833 by William Whewell, which soon replaced the older term of (natural) philosopher.

Among the most influential ideas of the 19th century were those of Charles Darwin (alongside the independent research of Alfred Russel Wallace), who in 1859 published the book On the Origin of Species, which introduced the idea of evolution by natural selection. Another important landmark in medicine and biology were the successful efforts to prove the germ theory of disease. Following this, Louis Pasteur made the first vaccine against rabies, and also made many discoveries in the field of chemistry, including the asymmetry of crystals. In chemistry, Dmitri Mendeleev, following the atomic theory of John Dalton, created the first periodic table of elements. In physics, the experiments, theories and discoveries of Michael Faraday, Andre-Marie Ampere, James Clerk Maxwell, and their contemporaries led to the creation of electromagnetism as a new branch of science. Thermodynamics led to an understanding of heat and the notion of energy was defined.

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 males and females will sexually reproduce and have offspring together. Domesticated animals are known as breeds, normally bred by a professional breeder, while domesticated plants are known as varieties, cultigens, cultivars, or breeds. Two purebred animals of different breeds produce a crossbreed, and crossbred plants are called hybrids. Flowers, vegetables and fruit-trees may be bred by amateurs and commercial or non-commercial professionals: major crops are usually the provenance of the professionals.

In animal breeding artificial selection is often combined with techniques such as inbreeding, linebreeding, and outcrossing. In plant breeding, similar methods are used. Charles Darwin discussed how selective breeding had been successful in producing change over time in his 1859 book, On the Origin of Species. Its first chapter discusses selective breeding and domestication of such animals as pigeons, cats, cattle, and dogs. Darwin used artificial selection as an analogy to propose and explain the theory of natural selection but distinguished the latter from the former as a separate process that is non-directed.

Nature versus nurture is a long-standing debate in biology and society about the relative influence on human beings of their genetic inheritance or biology (nature) and the environmental conditions of their development (nurture). Nature is what people think of as pre-wiring and is influenced by genetic inheritance and other biological factors. Nurture is generally taken as the influence of external factors after conception e.g. the product of exposure, experience and learning on an individual.

The phrase in its modern sense was popularized by the Victorian polymath Francis Galton, the modern founder of eugenics and behavioral genetics when he was discussing the influence of heredity and environment on social advancement. Galton was influenced by On the Origin of Species written by his half-cousin, the evolutionary biologist Charles Darwin. The complementary combination of the two concepts is an ancient concept (Ancient Greek: ἁπό φύσεως καὶ εὐτροφίας).

In evolutionary biology, what is now called the Baldwin effect describes the ways agency, imitation and learned behaviour can pioneer evolutionary change. It was first christened as such in the 1950s by George Gaylord Simpson, one of the architects of the modern synthesis, to bring attention to a process highlighted in the previous century by James Mark Baldwin.

Inspired to challenge late Victorian neo-darwinism by Darwin's own use of his theory of natural selection (in On the Origin of Species) to reframe the laws of use and disuse in terms of transitional habits—giving several examples of the ways different organisms' change of habits, as in flying squirrels and flightless beetles, have altered their anatomies' subsequent evolutionary fates—Baldwin and others re-emphasised that an organism's ability to learn new behaviours (e.g., to colonise new habitat or acclimatise to a new stressor) may affect its reproductive success and may, therefore, subsequently affect the genetic makeup of its species through natural selection, if supported by heritable traits. The Baldwin effect posits that, if such new habits prove advantageous, subsequent selection will reinforce those habits and any other structures they affect so that they will become instinctive or in-born over many generations. This process may appear similar to non-Darwinian Lamarckism, a view which proposes that living things may directly inherit their parents' acquired characteristics. But, in contrast to Lamarck, and echoing Darwin's argument about transitional habits in On the Origin of Species, Baldwin proposed that, only if supportable by heritable traits, can changed behaviour lead to adaptive evolutionary change.

Herbert Spencer (27 April 1820 – 8 December 1903) was an English polymath active as a philosopher, psychologist, biologist, sociologist, and anthropologist. Spencer originated the expression "survival of the fittest", which he coined in Principles of Biology (1864) after reading Charles Darwin's 1859 book On the Origin of Species. The term strongly suggests natural selection, yet Spencer saw evolution as extending into realms of sociology and ethics, so he also supported Lamarckism.

Spencer developed an all-embracing conception of evolution as the progressive development of the physical world, biological organisms, the human mind, and human culture and societies. As a polymath, he contributed to a wide range of subjects, including ethics, religion, anthropology, economics, political theory, philosophy, literature, astronomy, biology, sociology, and psychology. During his lifetime he achieved tremendous authority, mainly in English-speaking academia. Spencer was "the single most famous European intellectual in the closing decades of the nineteenth century" but his influence declined sharply after 1900: "Who now reads Spencer?" asked Talcott Parsons in 1937.

The Expression of the Emotions in Man and Animals is Charles Darwin's third major work of evolutionary theory, following On the Origin of Species (1859) and The Descent of Man, and Selection in Relation to Sex (1871). Initially intended as a chapter in Descent of Man, Expression grew in length and was published separately in 1872. Darwin explores the biological aspects of emotional behaviour and the animal origins of human characteristics like smiling and frowning, shrugging shoulders, blushing, the lifting of eyebrows in surprise, and baring teeth in an angry sneer.

A German translation of Expression appeared in 1872, and Dutch and French versions followed in 1873 and 1874. Though Expression has never been out of print since its first publication, it has also been described as Darwin's "forgotten masterpiece". Psychologist Paul Ekman has argued that Expression is the foundational text for modern scientific psychology.

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 as gene-culture coevolution.

Charles Darwin mentioned evolutionary interactions between flowering plants and insects in On the Origin of Species (1859). He used use the similar word coadaptation and suggested how plants and insects could evolve through reciprocal evolutionary changes. Naturalists in the late 1800s studied other examples of how interactions among species could result in reciprocal evolutionary change. Beginning in the 1940s, plant pathologists developed breeding programs that were examples of human-induced coevolution. Development of new crop plant varieties that were resistant to some diseases favored rapid evolution in pathogen populations to overcome those plant defenses. That, in turn, required the development of yet new resistant crop plant varieties, producing an ongoing cycle of reciprocal evolution in crop plants and diseases that continues to this day.