evening primrose Any of various species of herbaceous plants of the genus Oenothera (family Onagraceae). They are noted for their showy flowers, especially the yellow-flowered biennial O. biennis, which is found widely throughout North America and and has been introduced to Europe. It has been grown by geneticists to determine certain principles of heredity. The true primrose belongs to the family Primulaceae.
Evenk See Siberian peoples
event horizon Boundary marking the limits of a black hole. At the event horizon, the escape velocity is equal to the speed of light. Since general relativity states that nothing can travel faster than the speed of light, noth¬ ing inside the event horizon can ever cross the boundary and escape beyond it, including light. Thus, nothing that enters a black hole can get out or can be observed from outside the event horizon. Likewise, any radiation generated inside the horizon can never escape beyond it. For a nonrotating black hole, the Schwarzschild radius delimits a spherical event horizon. Rotating black holes have distorted, nonspherical event horizons. Since the event horizon is not a material surface but rather merely a math¬ ematically defined demarcation boundary, nothing prevents matter or radiation from entering a black hole, only from exiting one. Though black holes themselves may not radiate energy, electromagnetic radiation and matter particles may be radiated from just outside the event horizon via Hawking radiation.
Everest, Mount Tibetan Chomolungma \,cho-m6-Tur]-m3\ Nepali Sagarmatha Peak on the crest of the Himalayas, southern Asia. The highest point on Earth, with a summit at 29,035 ft (8,850 m), it lies on the border between Nepal and Tibet (China). Numerous attempts to climb Everest were made from 1921; the summit was finally reached by Edmund Hillary of New Zealand and Tenzing Norgay of Nepal in 1953. In dispute is whether the English explorer George Mallory, whose body was dis¬ covered below Everest’s peak in 1999, had actually reached the peak ear¬ lier, in 1924, and was descending it when he died. The formerly accepted elevation of 29,028 ft (8,848 m), established in the early 1950s, was recalculated in the late 1990s.
Everglades Subtropical saw-grass marsh region, southern Florida, U.S. Covering about 4,000 sq mi (10,000 sq km), the area has water moving slowly through it from the lip of Lake Okeechobee to mangrove swamps bordering the Gulf of Mexico and Florida Bay. Everglades National Park, established in 1934, encompasses the southwestern portion of the marsh, covering 2,354 sq mi (6,097 sq km). The largest subtropical wilderness left in the continental U.S., it has a mild climate, which provides an envi¬ ronment for myriad birds, alligators, snakes, and turtles. A large portion of the glades has been reclaimed by drainage canals, altering the habitats of many species.
evergreen Any plant that retains its leaves through the winter and into the following summer or through several years. Many tropical species of
broad-leaved flowering plants are evergreen, but in cold-temperate and Arctic areas the evergreens commonly are cone-bearing shrubs or trees (conifers), such as pines and firs. The leaves of evergreens usually are thicker and more leathery than those of deciduous trees and often are needlelike or scalelike in cone-bearing trees. A leaf (or needle) may remain on an evergreen tree for two years or longer and may fall during any season.
everlasting Any of several plants that retain their form and colour when dried and are used in dry bouquets and flower arrangements. Popu¬ lar everlastings include several species of the composite family, especially the true everlastings, or immortelles, species of the genus Helichrysum, native to North Africa, Crete, and the parts of Asia bordering on the Mediterranean and cultivated in many parts of Europe. One of the best- known everlastings is the strawflower ( H. bracteatum ) of Australia. Many GRASSes with showy plumes or spikes are classified as everlastings.
ever-normal granaries Price-stabilizing granaries first established in the 1st century bc. Under the Qing dynasty they were set up by all Chi¬ nese provinces in each county to keep grain on hand to offset regional food shortages in years of crop failure. By keeping the supply of grain stable (“ever normal”), the granaries stabilized prices, and even undevel¬ oped regions of the country were protected from famine.
Evers Ve-verzV Med gar (Wiley) (b. July 2, 1925, Decatur, Miss., U.S.—d. June 12, 1963, Philadelphia, Miss.) African American civil- rights activist. After serving in World War II he entered business in Mis¬ sissippi. He and his elder brother, Charles, began organizing local affiliates of the NAACP; in 1954 Medgar became the organization’s first field sec¬ retary in Mississippi. He traveled throughout the state recruiting members and organizing economic boycotts. In June 1963, hours after a speech on civil rights by Pres. John F. Kennedy, Evers was shot and killed in an ambush outside his home. A white segregationist was charged with the murder but was set free after two trials in 1964 resulted in hung juries; he was finally convicted after a third trial in 1994. Evers’s widow, Myr- lie Evers-Williams, later headed the NAACP (1995-98).
Evert, Chris(tine Marie) formerly Chris Evert Lloyd (b. Dec. 21, 1954, Fort Lauderdale, Fla., U.S.) U.S. tennis player. She became in 1971 the youngest player to reach the semifinals of the U.S. championship. She won the U.S. Open women’s singles six times (1975-78, 1980, 1982) and repeatedly won the Wimbledon singles (1974, 1976, 1981), the French Open singles (1974, 1975, 1979, 1980, 1983, 1985, 1986), and the Aus¬ tralian Open singles (1982, 1984), for a total of 18 grand-slam titles. She retired in 1989.
evidence In law, something (e.g., testimony, documents, or physical objects) presented at a judicial or administrative proceeding for the pur¬ pose of establishing the truth or falsity of an allegation of fact. To pre¬ serve legal due process and to prevent the jury from being misled, an extensive body of rules has sprung up regarding the handling of evidence. In the U.S., all federal and many state courts adhere to the Federal Rules of Evidence, which covers such elements as types of evidence, admissi¬ bility, relevance, competency of witnesses, confessions and admissions, expert testimony, and authentication. Most evidence received at trial is in the form of verbal statements of witnesses, who are subject to question¬ ing by attorneys from both sides. Two important categories of evidence are direct evidence, which is offered by a witness whose knowledge of a factual matter is firsthand (as through sight or hearing), and circumstan¬ tial evidence. See also exclusionary rule.
evil eye Superstition holding that a glance can cause injury or death to those on whom it falls. The belief was found in ancient Greece and Rome as well as in folk cultures around the world, and it has persisted into mod¬ ern times. Children and animals are believed to be particularly vulner¬ able. The evil eye is often thought to stem from envy and malice toward prosperity and beauty, and thus in many cultures unguarded praise of one’s possessions or children is thought to invite misfortune. Safeguards include amulets, charms, and sacred texts; in Asia children may have their faces blackened for protection.
Evita See Eva Peron
evolution Biological theory that animals and plants have their origin in other preexisting types and that the distinguishable differences are due to modifications in successive generations. It is one of the keystones of modern biological theory. In 1858 Charles Darwin and Alfred Russel Wal¬ lace jointly published a paper on evolution. The next year Darwin pre-
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sented his major treatise On the Origin of Species by Means of Natural Selection, which revolutionized all later biological study. The heart of Darwinian evolution is the mechanism of natural selection. Surviving indi¬ viduals, which vary (see variation) in some way that enables them to live longer and reproduce, pass on their advantage to succeeding generations. In 1937 Theodosius Dobzhansky applied Mendelian genetics (see Gregor Mendel) to Darwinian theory, contributing to a new understanding of evo¬ lution as the cumulative action of natural selection on small genetic varia¬ tions in whole populations. Part of the proof of evolution is in the fossil record, which shows a succession of gradually changing forms leading up to those known today. Structural similarities and similarities in embry¬ onic development among living forms also point to common ancestry. Molecular biology (especially the study of genes and proteins) provides the most detailed evidence of evolutionary change. Though the theory of evolution is accepted by nearly the entire scientific community, it has sparked much controversy from Darwin’s time to the present; many of the objections have come from religious leaders and thinkers (see cre¬ ationism) who believe that elements of the theory conflict with literal interpretations of the Bible. See also Hugo de Vries, Ernst Haeckel, human evolution, Ernst Mayr, parallel evolution, phylogeny, sociocultural evolution,