Mut \'mut\ In Egyptian religion, a sky goddess and divine mother. Mut may have originated either in the Nile River delta or in Middle Egypt. During the 18th dynasty (1539-1292 bc), she became the companion of the god Amon at Thebes. Amon, Mut, and the young god Khons (said to be her son) formed the Theban triad. The name Mut means “mother,” and her role was that of an older woman among the gods. She was usually represented as a woman wearing a double crown; she was also sometimes depicted with the head of a lioness.
mutagen Vmyii-to-jonV Any agent capable of altering a cell’s genetic makeup by changing the structure of the hereditary material, DNA. Many forms of electromagnetic radiation (e.g., cosmic rays, X rays, ultraviolet light) are mutagenic, as are various chemical compounds. The effects of some mutagens are increased or suppressed in some organisms by the presence of certain other, nonmutagenic substances; oxygen, for example, makes cells more sensitive to the mutagenic effects of X rays.
Mutanabb? N.mu-ta-'nab-beV (Abu al-Tayyib Ahmad ibn Husayn) al- (b. 915, Al-Kufah, Iraq—d. Sept. 23, 965, near Dayr al- c Aqul) Poet regarded by many as the greatest in the Arabic language. Al-MutanabbI received an education, unusual for his time and rank, because of his poetic talent. He lived among the Bedouin and, claiming to be a prophet, led an unsuccessful Muslim revolt in Syria. After two years’ imprisonment he recanted and became a wandering poet, eventually leav¬ ing Syria for Egypt and Iran. He primarily wrote panegyrics in a flowery, bombastic style marked by improbable metaphors. His poetic voice is proud and arrogant in tone, and his verse is crafted with consummate skill and artistry. His powerful influence on Arabic poetry persisted into mod¬ ern times.
mutation Alteration in the genetic material of a cell that is transmitted to the cell’s offspring. Mutations may be spontaneous or induced by out¬ side factors (mutagens). They take place in the genes, occurring when one base is substituted for another in the sequence of bases that determines the genetic code, or when one or more bases are inserted or deleted from a gene. Many mutations are harmless, often masked by the presence of a dominant normal gene (see dominance). Some have serious consequences; for example, a particular mutation inherited from both parents results in sickle-cell anemia. Only mutations that occur in the sex cells (eggs or
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sperm) can be transmitted to the individual’s offspring. Alterations caused by these mutations are usually harmful. In the rare instances in which a mutation produces a beneficial change, the percentage of organisms with this gene will tend to increase until the mutated gene becomes the norm in the population. In this way, beneficial mutations serve as the raw mate¬ rial of EVOLUTION.
Mu'tazilah \mu-'ta-zi-b\ In Islam, one of two early religious groups. The term applies primarily to members of a theological school that flourished in Al- Basrah and Baghdad in the 8th-10th century. These Mu'tazilah were the first Muslims to employ systematically the categories and methods of Hel¬ lenistic philosophy to derive their dogma. The tenets of their faith included belief in the oneness of God ( tawhid ), advocation of human free will (the ability to choose between good and evil), and the fundamental belief in God’s fairness (i.e., God will punish only those deserving of punishment). Their doctrine of a created Qur’an (the eternal nature of which was advo¬ cated by their opponents) held sway in the caliphal court briefly in the early 9th century and was the first instance in the Muslim world in which politi¬ cal authorities attempted to enforce any form of doctrinal rigour; the Mu'tazilah theological program soon lost political sway, however, and had faded by the 13th century. Though it was ultimately abandoned by Sunnite Muslims (the group’s methods came to be accepted by some ShTite groups), its true importance lay in the fact that it forced other theological groups to embrace a more rigorous dialectical method (see kalam).
mutiny Any concerted resistance to lawful military authority. Mutiny was formerly regarded as a most serious offense, especially aboard ships at sea. Wide disciplinary powers were given the commanding officer, including the power to inflict capital punishment without a court-martial. With the development of radio communications, the threat diminished and harsh punishment was prohibited in the absence of a court-martial.
Mutsuhito See Meiji emperor
mutual fund or unit trust or open-end trust Company that invests the funds of its subscribers in diversified securities and issues units representing shares in those holdings. It differs from an investment trust, which issues shares in the company itself. While investment trusts have a fixed capitalization and a limited number of shares for sale, mutual funds make a continuous offering of new shares at net asset value (plus a sales charge) and redeem their shares on demand at net asset value, determined daily by the market value of the securities they hold.
Muwahhidun, al- North African dynasty: see Almohad dynasty; Ara¬ bian religious group: see Wahhabi
Muybridge Vml-.brijV Eadweard orig. Edward James Mug- geridge (b. April 9, 1830, Kingston upon Thames, Surrey, Eng.—d. May 8, 1904, Kingston upon Thames) English photographer. He immi¬ grated to the U.S. from England as a young man, and in 1868 his photos of Yosemite Valley made him famous. Hired by Leland Stanford to pho¬ tograph a trotting horse in motion, to test Stanford’s contention that it lifted all four legs simultaneously, he developed a special fast shutter for his battery of 12 to 24 cameras, and in 1877 he proved Stanford right. He lectured widely on animal locomotion, illustrating his lectures with his zoopraxiscope, a predecessor of the movie projector. His extensive pho¬ tographic studies of human movement (1884-87) have been useful to art¬ ists and scientists.
Mwene Mata pa Vmwa-na-ma-'ta-poX Title borne by a line of kings ruling a South African territory between the Zambezi and Limpopo riv¬ ers, in what is now Zimbabwe and Mozambique, from the 14th to the 17th century. Their domain, often called Matapa (or Mutapa), is associ¬ ated with the historical site of Great Zimbabwe in southeastern Zimbabwe.
Mweru, Lake \'mwa-ru\ French Lac Moero X.lak-mwa-'roX Lake, central Africa. It is located on the boundary between southeastern Demo¬ cratic Republic of the Congo (Zaire) and Zambia, west of the southern tip of Lake Tanganyika. Part of the Congo River system, it is 76 mi (122 km) long and has a surface area of 1,900 sq mi (4,920 sq km). The Lua- pula River, a headstream of the Congo River, flows through it. The Bang- weulu Swamps adjoin the lake.
My Lai \'me-Tl\ Massacre (March 16, 1968) Mass killing of as many as 500 unarmed villagers by U.S. soldiers in the hamlet of My Lai dur¬ ing the Vietnam War. A company of U.S. soldiers on a search-and-destroy mission against the hamlet found no armed Viet Cong there but nonethe¬ less killed all the elderly men, women, and children they could find; few
villagers survived. The incident was initially covered up by high-ranking army officers, but it was later made public by former soldiers. In the ensu¬ ing courts-martial, platoon leader Lt. William Calley was accused of directing the killings and was convicted of premeditated murder and sen¬ tenced to life in prison; but Pres. Richard Nixon intervened on his behalf, and he was paroled after three years. The massacre and other atrocities revealed during the trial divided the U.S. public and contributed to grow¬ ing disillusionment with the war.