Charles Darwin

Sir Julian Sorell Huxley FRS (22 June 1887 – 14 February 1975) was an English evolutionary biologist, eugenicist and internationalist. He was a proponent of natural selection, and a leading figure in the mid-twentieth-century modern synthesis. He was secretary of the Zoological Society of London (1935–1942), the first director of UNESCO, a founding member of the World Wildlife Fund, the president of the British Eugenics Society (1959–1962), and the first president of the British Humanist Association.

Huxley was well known for his presentation of science in books and articles, and on radio and television. He directed an Oscar-winning wildlife film. He was awarded UNESCO's Kalinga Prize for the popularisation of science in 1953, the Darwin Medal of the Royal Society in 1956, and the Darwin–Wallace Medal of the Linnaean Society in 1958. He was also knighted in the 1958 New Year Honours, a hundred years after Charles Darwin and Alfred Russel Wallace announced the theory of evolution by natural selection. In 1956 he received a Special Award from the Lasker Foundation in the category Planned Parenthood – World Population.

The modern synthesis was the early 20th-century synthesis of Charles Darwin's theory of evolution and Gregor Mendel's ideas on heredity into a joint mathematical framework. Julian Huxley coined the term in his 1942 book, Evolution: The Modern Synthesis. The synthesis combined the ideas of natural selection, Mendelian genetics, and population genetics. It also related the broad-scale macroevolution seen by palaeontologists to the small-scale microevolution of local populations.

The synthesis was defined differently by its founders, with Ernst Mayr in 1959, G. Ledyard Stebbins in 1966, and Theodosius Dobzhansky in 1974 offering differing basic postulates, though they all include natural selection, working on heritable variation supplied by mutation. Other major figures in the synthesis included E. B. Ford, Bernhard Rensch, Ivan Schmalhausen, and George Gaylord Simpson. An early event in the modern synthesis was R. A. Fisher's 1918 paper on mathematical population genetics, though William Bateson, and separately Udny Yule, had already started to show how Mendelian genetics could work in evolution in 1902.

Paleontology or palaeontology is the scientific study of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geologic time, and assess the interactions between prehistoric organisms and their natural environment. While paleontological observations are known from at least the 6th century BC, the foundation of paleontology as a science dates back to the work of Georges Cuvier in 1796. Cuvier demonstrated evidence for the concept of extinction and how the life of the past was not necessarily the same as that of the present. The field developed rapidly over the course of the following decades, and the French word paléontologie was introduced for the study in 1822, which was derived from the Ancient Greek word for 'ancient' and words describing relatedness and a field of study. Further advances in the field accompanied the work of Charles Darwin who popularized the concept of evolution. Together, evolution and extinction can be understood as complementary processes that shaped the history of life.

Paleontology overlaps the most with the fields of geology and biology. It draws on technology and analysis of a wide range of sciences to apply them to the study of life and environments of the past, particularly for the subdisciplines of paleobiology and paleoecology that are analogous to biology and ecology. Paleontology also contributes to other sciences, being utilized for biostratigraphy to reconstruct the geologic time scale of Earth, or in studies on extinction to establish both external and internal factors that can lead to the disappearance of a species. Much of the history of life is now better understood because of advances in paleontology and the increase in interdisciplinary studies. Several improvements in understanding have occurred from the introduction of theoretical analysis to paleontology in the 1950s and 1960s which led to the rise of more focused fields of paleontology that assess the changing geography and climate of Earth, the phylogenetic relationships between different species, and the analysis of how fossilization occurs and what biases can impact the quality of the fossil record.

Sexual selection is a mechanism of evolution in which members of one sex choose mates of the other sex to mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex (intrasexual selection). These two forms of selection mean that some individuals have greater reproductive success than others within a population, for example because they are more attractive or prefer more attractive partners to produce offspring. Successful males benefit from frequent mating and monopolizing access to one or more fertile females. Females can maximise the return on the energy they invest in reproduction by selecting and mating with the best males.

The concept was first articulated by Charles Darwin who wrote of a "second agency" other than natural selection, in which competition between mate candidates could lead to speciation. The theory was given a mathematical basis by Ronald Fisher in the early 20th century. Sexual selection can lead males to extreme efforts to demonstrate their fitness to be chosen by females, producing sexual dimorphism in secondary sexual characteristics, such as the ornate plumage of birds-of-paradise and peafowl, or the antlers of deer. Depending on the species, these rules can be reversed. This is caused by a positive feedback mechanism known as a Fisherian runaway, where the passing-on of the desire for a trait in one sex is as important as having the trait in the other sex in producing the runaway effect. Although the sexy son hypothesis indicates that females would prefer male offspring, Fisher's principle explains why the sex ratio is most often 1:1. Sexual selection is widely distributed in the animal kingdom, and is also found in plants and fungi.

Evolutionary developmental biology, informally known as evo-devo, is a field of biological research that compares the developmental processes of different organisms to infer how developmental processes evolved.

The field grew from 19th-century beginnings, where embryology faced a mystery: zoologists did not know how embryonic development was controlled at the molecular level. Charles Darwin noted that having similar embryos implied common ancestry, but little progress was made until the 1970s. Then, recombinant DNA technology at last brought embryology together with molecular genetics. A key early discovery was that of homeotic genes that regulate development in a wide range of eukaryotes.

Natural selection is the differential survival and reproduction of individuals due to differences in the relative fitness endowed on them by their own particular complement of observable characteristics. It is a key law or mechanism of evolution which changes the heritable traits characteristic of a population or species over generations. Charles Darwin popularised the term "natural selection", contrasting it with artificial selection, which is intentional, whereas natural selection is not.

For Darwin natural selection was a law or principle which resulted from three different kinds of process: inheritance, including the transmission of heritable material from parent to offspring and its development (ontogeny) in the offspring; variation, which partly resulted from an organism's own agency (see phenotype; Baldwin effect); and the struggle for existence, which included both competition between organisms and cooperation or 'mutual aid' (particularly in 'social' plants and social animals).

The concept of the struggle for existence (or struggle for life) concerns the competition or battle for resources needed to live. It can refer to human society, or to organisms in nature. The concept is ancient, and the term struggle for existence was in use by the end of the 18th century. From the 17th century onwards the concept was associated with a population exceeding resources, an issue shown starkly in Thomas Robert Malthus’ An Essay on the Principle of Population which drew on Benjamin Franklin's Observations Concerning the Increase of Mankind, Peopling of Countries, etc..

It is sometimes forgotten that Charles Darwin used the term "struggle for existence" in what he called a metaphorical sense. This was because he used it to refer not only to direct competition between (and within) species but indirect competition (as with a plant at the edge of the desert). Darwin noted that the struggle for existence could also involve active or passive mutual aid between organisms of the same or different species, instancing social insects (see also symbiosis).

Christ's College is a constituent college of the University of Cambridge, England. The college includes the Master, the Fellows of the College, and about 450 undergraduate and 250 graduate students. The college was founded by William Byngham in 1437 as God's House. In 1505, the college was granted a new royal charter, was given a substantial endowment by Lady Margaret Beaufort, and changed its name to Christ's College, becoming the twelfth of the Cambridge colleges to be founded in its modern form.

Alumni of the college include the poet John Milton, the naturalist Charles Darwin, as well as the Nobel Laureates Martin Evans, James Meade, Alexander Todd, Duncan Haldane, and John Clarke. The Master is Lord McDonald of Salford.

The second voyage of HMS Beagle, from 27 December 1831 to 2 October 1836, was the second survey expedition of HMS Beagle, made under her newest commander, Robert FitzRoy. FitzRoy had thought of the advantages of having someone onboard who could investigate geology, and sought a naturalist to accompany them as a supernumerary. At the age of 22, the graduate Charles Darwin hoped to see the tropics before becoming a parson, and accepted the opportunity. He was greatly influenced by reading Charles Lyell's Principles of Geology during the voyage. By the end of the expedition, Darwin had made his name as a geologist, and fossil collector, and the publication of his journal (later known as The Voyage of the Beagle) gave him wide renown as a writer.

Beagle sailed across the Atlantic Ocean, and then carried out detailed hydrographic surveys around the coasts of southern South America, returning via Tahiti and Australia, after having circumnavigated the Earth. The initial offer to Darwin told him the voyage would last two years; it lasted almost five.

HMS Beagle was a Cherokee-class 10-gun brig-sloop of the Royal Navy, one of more than 100 ships of this class. The vessel, constructed at a cost of £7,803, was launched on 11 May 1820 from the Woolwich Dockyard on the River Thames. Later reports say the ship took part in celebrations of the coronation of George IV, passing under the old London Bridge, and was the first rigged man-of-war afloat upriver of the bridge. There was no immediate need for Beagle, so she "lay in ordinary", moored afloat but without masts or rigging. She was then adapted as a survey barque and took part in three survey expeditions.

The second voyage of HMS Beagle is notable for carrying the recently graduated naturalist Charles Darwin around the world. While the survey work was carried out, Darwin travelled and researched geology, natural history and ethnology onshore. He gained fame by publishing his diary journal, best known as The Voyage of the Beagle, and his findings played a pivotal role in the formation of his scientific theories on evolution and natural selection.