YEAR IN REVIEW 1996: WORLD-AFFAIRS: VIETNAM

Vietnam: Vietnam Reemerges On April 30, 1995, amid colourful billboards, bustling cafes, and roaring motorbikes, the Vietnamese people celebrated the 20th anniversary of the end of a war that had both devastated and unified their nation. As Communist Party members and invited guests watched a grand parade move through Ho Chi Minh City, once known as Saigon, they had reason to feel both thrilled and uneasy. These conflicting sentiments were visible everywhere as Vietnamese sought to release their pent-up energy and realize their potential while not forgetting that the freedom they enjoyed had been secured by communist soldiers. Since the institution of doi moi (economic renovation) in 1986, Vietnam's economy had thrived. While it was still among the poorest of the less developed nations (its gross national product per capita was $220), it had had more than 8% annual growth for the previous four years. Inflation had fallen from 700% in 1986 to 14.4% in 1995. Land reforms that gave more control and greater profits to farmers had been a tremendous success. A nation that once could barely feed itself was now the world's third largest exporter of rice. Vietnam's liberal investment laws, moreover, had triggered an enormous influx of money from neighbouring nations. With the end of the U.S. trade embargo in 1994 and the restoration of normal diplomatic relations between the U.S. and Vietnam in 1995, there was great promise of even more foreign investment. Chrysler planned to build cars there, Mobil Oil was searching for petroleum offshore, and Coca-Cola was the country's trendiest drink. Finally, with financial incentives from both Vietnam and developed nations, many boat people who fled the country had returned home. All this positive growth, however, carried with it a deep concern about unintended and undesirable consequences. Within the government there was heated debate about privatizing the economy and opening markets to outsiders. Many hard-line communists feared that the power and autonomy that they fought so hard for would be lost with the emergence of free markets. Such fears had already led to several setbacks for Vietnam's new economy. The conversion of agricultural land for industrial use had been stopped, and so had borrowing against land values. The government's uncertain long-term commitment to open trade had scared off many potential investors. The progress of the past decade had also deeply affected the culture of Vietnam. There was an unrestrained mania for all things Western, and the prospect of growing wealthy had, for example, tempted both students and teachers to seek well-paying jobs in the business sector. Vietnam's future would largely depend on who succeeded Communist Party leader Do Muoi and Prime Minister Vo Van Kiet. Perhaps the most important development in Vietnam during the year was its admission into the Association of Southeast Asian Nations in July. By linking its own economic strategies with those of noncommunist Thailand, Malaysia, Singapore, Indonesia, the Philippines, and Brunei and pursuing peaceful relations with other nations, it had shown that, as popular T-shirts in Ho Chi Minh City declared, Vietnam is a country, not a war. (JAMES HENNELLY) WESTERN SAMOA A constitutional monarchy and member of the Commonwealth, Western Samoa occupies an island group in the South Pacific Ocean. Area: 2,831 sq km (1,093 sq mi). Pop. (1995 est.): 166,000. Cap.: Apia. Monetary unit: Western Samoa tala, with (Oct. 6, 1995) a free rate of 2.50 tala to U.S. $1 (3.95 tala = 1 sterling). Head of state (O le Ao o le Malo) in 1995, Malietoa Tanumafili II; prime minister, Tofilau Eti Alesana. In February 1995, after a petition (with some 80,000 signatures) opposing the new value-added goods and services tax was submitted to Parliament, the government laid sedition charges against two leaders of Tumua ma Pule, an organization of traditional chiefs and orators. The case was dismissed by the Supreme Court in June. An Audit Office report, severely critical of the government and alleging mismanagement and corruption, led to the dismissal of the Controller and Chief Auditor. After a 6% contraction in 1994, the government anticipated 5% economic growth in 1995 and 1996. Inflation, 18.4% in 1994, was expected to be less than 10% in 1995. The government took control of Polynesian Airlines and injected $30 million to keep the company afloat. Two-thirds of aircraft leases were terminated, and route sharing with Air New Zealand was introduced as part of a recovery plan. Western Samoa joined other South Pacific Forum nations in protesting against the resumption of French nuclear testing in the region. (BARRIE MACDONALD) This updates the article Western Samoa. YEMEN A republic of the southwestern Arabian Peninsula, Yemen has coastlines on the Red Sea, the Gulf of Aden, and the Arabian Sea. Area: 527,970 sq km (203,850 sq mi), including 55,871 sq km of undemarcated area bordered by Saudi Arabia and claimed by the former Yemen Arab Republic (North Yemen). Pop. (1995 est.): 13,058,000. Cap.: San'a`. Monetary unit: Yemen Rial, with (Oct. 6, 1995) an official par value of YRls 50 to U.S. $1 (YRls 79.04 = 1 sterling) and a free market rate of YRls 140 to U.S. $1 (YRls 221.32 = 1 sterling). President in 1995, Maj. Gen. Ali Abdallah Salih; prime minister, 'Abd al-Aziz 'Abd al-Ghani. Despite tensions, Yemen retained its national unity throughout 1995. Eleven parties agreed in February to a document establishing a new alliance, the Opposition Democratic Coalition. In March the minister of defense declared that the integration of the northern and southern armed forces had been "successfully completed." In June a Cabinet reshuffle further consolidated the power of the president, Maj. Gen. Ali Abdallah Salih, by tipping the balance of the coalition government in favour of his General People's Congress over the Yemeni Alliance for Reform. Border tensions with Saudi Arabia, which had heated up in December 1994 and January 1995, led to the signing in February of a memorandum of understanding. The parties renewed their commitment to the agreement signed in at-Ta`if, Saudi Arabia, in 1934 and established joint committees to arrive at definitive boundaries and promote bilateral ties. There were subsequent talks, and in June President Salih met with King Fahd. Later in the year, however, there were further border clashes. Agreement was reached defining the boundaries with Oman. In December Yemen accused Eritrea of "armed aggression" for landing forces on the Hanish Islands in the Red Sea. After fighting in the area was followed by a cease-fire, the Eritreans continued to hold one of the islands at year-end. Estimated daily oil production averaged 340,000 bbl in 1995. The World Bank granted an economic recovery credit of $80 million in December as various free-market reforms began to get under way. (JAMAL A. SA'D) This updates the article Yemen, history of. YUGOSLAVIA A federal republic comprising the republics of Serbia and Montenegro, Yugoslavia borders Hungary to the north, Romania to the northeast, Bulgaria to the southeast, Macedonia and Albania to the south, the Adriatic Sea to the southwest, and Croatia and Bosnia and Herzegovina to the west. Area: 102,173 sq km (39,449 sq mi). Pop. (1995 est.): 10,555,000. Cap.: Belgrade. Monetary unit: new dinar (second), with (Oct. 6, 1995) a par value equal to the Deutsche Mark (free rates of 1.42 new dinars = U.S. $1 and 2.25 new dinars = 1 sterling). President in 1995, Zoran Lilic; prime minister, Radoje Kontic. Serbia's president, Slobodan Milosevic, regarded by many as the principal instigator of the war in former Yugoslavia, continued to play a key role in the peace process in Bosnia and Herzegovina in 1995. As before, his main concern seemed to be the lifting of UN sanctions imposed on Yugoslavia in May 1992 because of its involvement in the Bosnian war. Meanwhile, Milosevic continued to maintain a firm grip on power at home in Serbia and, to lesser degree, in Montenegro. During the first half of 1995, Yugoslavia continued to supply military aid and personnel to the Serbs of western Slavonia and the self-declared "Serb Republic of Krajina" in Croatia. In response to appeals from Croatian Serbs for more soldiers, the Yugoslav authorities rounded up able-bodied Serbs from Croatia living in Serbia and sent them to the Serb-controlled regions of Croatia. Politically, however, Yugoslavia continued to distance itself from the Croatian Serbs and their policy of close cooperation with the Bosnian Serb leaders, Radovan Karadzic and Ratko Mladic. Yugoslavia made no attempt to go to the aid of Serbs of western Slavonia in May or the Serbs of the Krajina in August when Croatia recaptured these areas in lightning military actions. Some Serb refugees were allowed to enter Yugoslavia and were typically sent either to Kosovo province, largely populated by the Albanian minority, or to Vojvodina, where they were given the homes of Croats and Hungarians who had fled or been expelled. In June Milosevic played a key role in the release of UN hostages who had been captured by Bosnian Serbs following NATO raids on arms dumps near Pale, the Bosnian Serb headquarters near Sarajevo. Milosevic sent Jovica Stanisic, his chief of secret police, to put pressure on Karadzic and Mladic to release the hostages. They were all released by June 18. On November 28 Milosevic carried out a purge of pro-Karadzic members of his own party, including the party's vice president, Borislav Jovic, his close ally from the last days of former Yugoslavia, and Mihailo Markovic, Milosevic's chief ideologue in the Socialist Party of Serbia (SPS), the recycled League of Communists of Serbia. Jovic published a diary late in the year that was extremely unflattering of the Serbian president and suggested that he deliberately began the war in Yugoslavia. A similar purge had been carried out earlier in the organs of the mass media, where heads of radio and television as well as of some of the most important newspapers, such as the daily Politika, were replaced by people more attuned to Milosevic's policy in Bosnia. The Bosnian Serbs' military actions in July, the bloody conquest of Srebrenica and Zepa, the threat to Gorazde, and the military push in the Bihac area all contributed to the marginalization of the Serbian political opposition. Meanwhile, Milosevic seemed to be attempting, with the aid of his wife, Mirjana Markovic, who led a small party called the United Yugoslav Left, to take Serbia away from a policy of overt nationalism. Often by precipitating scandals or using other means of pressure, pro-government people were slowly taking over constituencies where the opposition had won in 1993. The most radical nationalist opponent of Milosevic's, Vojislav Seselj, an erstwhile ally, had been imprisoned following an incident engineered by the secret police. His parliamentary immunity was lifted during a nocturnal session of the parliament, and he was quickly packed off to prison. Opinion polls, even in the small independent Belgrade press, showed Milosevic by far the most popular politician in the country. His popularity in Serbia increased still further in the wake of the U.S.-brokered negotiations at Dayton, Ohio, in November at which he was seen to be playing a key role, negotiating on behalf of the Bosnian Serbs. Milosevic's greatest triumph in the eyes of war-weary Serbs was the lifting of sanctions by the United States after the signing of the Balkan accords in Paris on December 14. Throughout the year the constituent republic of Montenegro demonstrated irritation with Serbian policies. It refused to cooperate in the roundup of Serb troops to fight in Croatian territories, and it viewed Serbia's refusal to recognize Croatia unless it ceded the strategic Prevlaka promontory (at the entrance to the Yugoslav Gulf of Kotor naval base) as a potential threat to Montenegro's postwar relations with Croatia. In October Montenegro withheld payment of customs duties and taxes to the federal government as a protest against its nonpayment of Montenegrin pensions and disability benefits. One of the most prominent figures from the Tito era, Milovan Djilas, a dissident and writer hailing from Montenegro, died on April 20 at the age of 83. Industrial production in Yugoslavia in January-November 1995 was 4.6% higher than in the corresponding period of 1994 but 48.5% lower than in 1991. Inflation was running at an annual rate of 114%. (K.F. CVIIC) This updates the article Yugoslavia, history of. ZAIRE The republic of Zaire is located in central Africa with a short coastline on the Atlantic Ocean. Area: 2,344,858 sq km (905,354 sq mi). Pop. (1995 est.): 43,901,000 (excluding 1.1 million Rwandan refugees). Cap.: Kinshasa. Monetary unit: new zare, with (Oct. 6, 1995) a free rate of 5,422 new zares to U.S. $1 (8,572 new zares = 1 sterling). President in 1995, Mobutu Sese Seko; first state commissioner (prime minister), Joseph Kengo Wa Dondo. In his 1995 New Year message, Pres. Mobutu Sese Seko said that the future prosperity of the country depended upon putting an end to political confusion. Soon afterward direct talks began between government representatives and members of the Sacred Union of the Radical Opposition and Allies (USORAS), which led to an announcement of cooperation by opposition leader and former prime minister tienne Tshisekedi on January 7. The press was more skeptical, accusing members of the national legislature of devoting more time to political squabbles than to legislative business, and by January 27 USORAS was demanding that the Supreme Court annul the appointment of Kengo Wa Dondo as prime minister. Yet it was Kengo's appointment that encouraged foreign governments, including the U.S., to look more favourably on relations with Zaire. Meanwhile, none appeared capable of halting or even of slowing down the galloping inflation that had driven the majority of people to rely on barter. The prime minister's efforts to bring the banks back into operation were foundering owing to a shortage of cash. Concern for the political stability of the country was briefly pushed aside in May by news of deaths from the Ebola virus in Kikwit, 500 km (310 mi) east of Kinshasa. The outbreak, the origin of which remained obscure, was quickly contained, and fewer than 300 people died from the disease. The speed with which the infection overwhelmed its victims and the dreadful nature of its progress caused widespread disquiet, however. The announcement that the transitional government would continue in office for an additional two years because it was impossible to arrange elections in time to meet the deadline previously set gave rise to another wave of unrest. Clashes on July 29 between security forces and demonstrators loyal to the memory of assassinated former prime minister Patrice Lumumba resulted in the deaths of nine civilians and one police officer. Leaders of USORAS, while dissociating themselves from the Lumumbist cause, insisted that the clashes would not deter them from conducting a campaign to oust Kengo Wa Dondo and to reinstate Tshisekedi as prime minister. A rally called to launch the campaign on August 6 took place peacefully. Later in August attention became focused on the more than one million refugees from Rwanda and Burundi who were living in camps just inside the country's eastern border. The local population had for some time complained of food shortages in the region and said that the refugees were cutting down vast numbers of trees to use for firewood and as building materials. In June and July more than 100 Zaireans were reported to have been killed in clashes with the refugees, which prompted the prime minister to ask the refugees to return home. The government was gravely concerned about the security problems created by the existence of the camps and was dissatisfied with the inadequate provisions made for the refugees by the international community. When the UN Security Council resolved on August 16 to end its embargo on the sale of arms to Rwanda, the government protested. It argued that this could only lead to attacks on the camps by Rwandan soldiers seeking reprisals against those responsible for the massacres in Rwanda that had led to the revolution there. Zaire's response was to begin the forcible repatriation of refugees on August 19. This caused an international outcry, but representatives of aid agencies in the camps recognized that the government's action had encouraged many of the refugees who wanted to go home to say so openly. Previously, they had been afraid to act because of rumours that they would be arrested or killed if they did so. As a result, the UN High Commissioner for Refugees offered on August 24 to transform the expulsion program into a scheme for voluntary repatriation, an offer that the government readily accepted. (KENNETH INGHAM) This updates the article Congo, history of. ZAMBIA A landlocked republic and member of the Commonwealth, Zambia is in eastern Africa. Area: 752,614 sq km (290,586 sq mi). Pop. (1995 est.): 9,456,000. Cap.: Lusaka. Monetary unit: kwacha, with (Oct. 6, 1995) a free rate of 941 kwacha to U.S. $1 (1,489 kwacha = 1 sterling). President in 1995, Frederick Chiluba. With yet another prolonged period of drought causing acute shortages of food in the southern half of the country and with the output of copper continuing to fall--though the effect of this was partially offset by the increase in world prices--Zambia started 1995 in a beleaguered condition. The decline in copper production, coupled with the reopening of trade with South Africa and peace in Mozambique, also resulted in a serious reduction in traffic on the Tanzam railway and led to proposals to reduce the workforce from 6,600 to 4,000. By the admission of Minister of Commerce Dipak Patel in July, 5.5 million of Zambia's 9.5 million people were living in abject poverty. Accusations that after 40 months in office his government still had not formulated a policy for agriculture, together with charges of corruption leveled against his administration, led Pres. Frederick Chiluba to take drastic action. On February 9 he ordered all his ministers and members of the National Assembly to declare their assets within 48 hours. He had already dismissed his minister of lands, Chuulu Kalima, for gross indiscipline and irresponsibility. He followed this, a few weeks later, by sacking the governor of the Bank of Zambia, Dominic Mulaisho, when the value of the kwacha suddenly and inexplicably fell by more than 20% and after criticism that the bank had failed to foresee and forestall the crisis that led to the failure of Meridien BIAO, Zambia's fourth largest commercial bank. Chiluba also pointed out that economic recovery could not be expected as long as the country was burdened with a crushing international debt, the servicing of which cost 40% of the gross national product. The president's actions did not put an end to sniping by the opposition, including the charge (firmly denied) that he was born in Zaire and therefore not entitled to hold office in Zambia. When on June 28 former president Kenneth Kaunda was again elected leader of the opposition United National Independence Party, he, too, was accused of having been president of the country for five years before renouncing his Malawian citizenship. A threat to deport him from Zambia was dropped, although a clause in the country's proposed new constitution, stating that candidates for the presidency must be citizens whose parents were both Zambians by birth, presented a further obstacle to Kaunda's hoped-for comeback. (KENNETH INGHAM) This updates the article Zambia, history of. ZIMBABWE A republic and member of the Commonwealth, Zimbabwe is a landlocked state in eastern Africa. Area: 390,757 sq km (150,872 sq mi). Pop. (1995 est.): 11,261,000. Cap.: Harare. Monetary unit: Zimbabwe dollar, with (Oct. 6, 1995) a free rate of Z$8.85 to U.S. $1 (Z$14 = 1 sterling). President in 1995, Robert Mugabe. A meeting of Zimbabwe's donor countries, scheduled to take place in Paris in February 1995, was postponed until March to give the government time to "put its books in order." Although there were fears that donors were becoming impatient at the slow rate at which the country was implementing the financial reforms required by the International Monetary Fund (IMF) and the World Bank, the latter agreed on March 10 to ratify disbursements to Zimbabwe of $792 million, an increase of $175 million over the amount already committed. The donor countries praised the government for its efforts to carry out the reforms. Those efforts had not met with uniform approval inside Zimbabwe. New excise taxes and the threat of a new surcharge on profits and income aroused considerable criticism, which led Pres. Robert Mugabe to express his anger at the severity of the measures his government was having to take to meet the requirements of the IMF and the World Bank. The situation was not helped by the lengthy illness of the finance minister, Bernard Chidzero. In his absence there had been some mismanagement of public spending. Other factors that adversely affected the country's economic prospects were not easily dealt with. Continuing drought led to food shortages and to a wheat crop that was barely a third of the 1994 harvest. Also, the national debt was almost equal to the annual gross domestic product, which caused 23% of the budget to be earmarked for interest payments. The general election, held in April, did not appreciably change the situation. Owing in part to a boycott by several opposition parties, which claimed that the electoral system was unfairly weighted against them, the governing Zimbabwe African National Union-Patriotic Front (ZANU-PF) won all but two seats in the House of Assembly. The new minister of finance, Ariston Chambati, recognized that the credibility of his July budget would depend upon "a high degree of political commitment and fiscal discipline." Though he died of meningitis in October, Chambati had imposed a virtual standstill on public spending, increased taxes on a number of consumer goods, and reduced import duties on spare parts and industrial components. Increases in the tobacco crop and in the output of gold--the two main foreign currency earners--provided grounds for optimism. Also encouraging was a deal in April involving three of the world's largest mining companies, which opened the way for Zimbabwe to become the second biggest producer of platinum. In October Ndabaningi Sithole, leader of the ZANU-Ndonga and one of the only two non-ZANU-PF members of the House of Assembly was arrested in connection with an alleged plot to assassinate President Mugabe. Critics of Mugabe believed that the arrest was the result of Sithole's announcement that he would be a candidate in the presidential election in 1996 and was, consequently, a further manifestation of Mugabe's refusal to allow any opposition. (KENNETH INGHAM) This updates the article Zimbabwe, history of. ZOOLOGY A keener awareness of global conservation issues emerged during 1995 from research involving a variety of animal groups. In addition, scientists discovered new reproductive traits related to mate selection, parental care, and the induction of egg hatching in several species. To examine factors that control the presence and absence of animal species on islands and that contribute to the success of colonization, Thomas W. Schoener and David A. Spiller of the University of California, Davis, conducted a difficult but informative experiment. Their objective was to test the relative influence of island size and the presence of predators on the colonization success of prey species. They selected islands from a chain in The Bahamas, of which five each were large ones with predatory lizards, Anolis sagrei; large ones without lizards; and small ones without lizards. They selected a common orb spider, Metepeira datona, native to the region but absent on all of the test islands, as the artificially introduced prey species. In the first year of the experiment, spiders of both sexes were released on each of the 15 islands, and in the following year three times as many were released. By the end of the five-year experiment, the introduced spiders were extinct on all islands with lizards. One small island still had spiders, and three of the large lizardless islands had enormous spider populations. The investigators concluded that the presence of predators strongly influenced survival success and persistence of spiders. In some ways island size was less important, suggesting that more emphasis in conservation ecology should be given to studying predation effects on islands. Zoological studies in temperate climates offered evidence that threats to biological diversity and to the environment are global in scale and not confined to tropical terrestrial ecosystems or restricted to less developed countries. Charles Lydeard and Richard L. Mayden of the University of Alabama reported on imperiled aquatic animals of the rivers and streams of the Mobile Basin in the southeastern U.S. They showed that the biodiversity of native fish, aquatic snails, mussels, and turtles in the temperate-zone ecosystem rivals that of many higher-profile tropical systems. The extraordinarily high species diversity found there was attributed to circumstances of the area's surface features and river-drainage history. Many species in the region remained undescribed, and the ecology and life history of the majority were poorly known. Numerous snails and mussels and at least two fish species in the region were known to have become extinct in the past century. Because declines and extirpations of species populations can be directly attributed to general habitat degradation, Lydeard and Mayden emphasized the importance of strengthening environmental protection regulations to safeguard entire ecosystems rather than just particular species. Karen A. Kidd and David W. Schindler of the University of Alberta and colleagues offered an explanation for the presence of unusually high levels of the pesticide toxaphene in fish from a subarctic lake. The use of toxaphene as an agricultural insecticide and fish-killing agent was discontinued in the U.S. and Canada in the 1980s but continued in Mexico, parts of South America, Africa, and Asia. The chlorinated compound is transported via the atmosphere to Arctic regions and in 1991 was detected in lake trout (Salvelinus namaycush), burbot (Lota lota), and whitefish (Coregonus clupeaformis) from Lake Laberge, Yukon Territory, at levels considered hazardous to human health. Although the same fish species in other lakes in the region also contained toxaphene, levels in the Lake Laberge fish were higher. Kidd, Schindler, and co-workers showed that the higher levels were caused by biological concentration, or biomagnification, of toxaphene up an unusually long food chain. In the other lakes the fish in question eat mostly invertebrates, whereas those in Lake Laberge feed heavily on other fish. By occupying the top of a longer food chain, the Lake Laberge fish accumulate more toxaphene than do the same fish species in other regional lakes. Bill Amos of the University of Cambridge and colleagues found evidence of mate fidelity in the gray seal (Halichoerus grypus), generally considered a purely polygynous species in which males compete with each other for territories and mates. Seals born on the island of North Rona, Scotland, were genetically analyzed to determine which pups were full siblings--i.e., shared the same father and mother. The number was high, although dominant males in the breeding colony fathered an unexpectedly small proportion of the full sibs, indicating significant partnering between females and subordinate males. The investigators concluded that although some males are polygynous, many show partner fidelity, mating with the same female year after year. Partner fidelity should increase survival rates of seal pups by reducing fights between males over females, which by disturbing the clan are often a major cause of pre-weaning deaths. Rudolf Diesel and Gernot Burle of the University of Bielefeld, Germany, and Peter Vogel of the University of the West Indies, Kingston, Jamaica, reported the first known instance in which frogs breed in caves and transport their fully developed young to the outside. The investigators observed male Jamaican frogs (Eleutherodactylus cundalli) calling from as far back as 87 m (285 ft) from the cave entrance to attract females. After mating, females laid eggs in the cave in total darkness, attended them for about a month, and then carried the hatchlings out of the cave on their backs. Egg laying in caves and the subsequent transport of newborn frogs were theorized to have evolved as a way to maintain developing eggs in a relatively predator-free environment and then to place the young in a productive habitat after birth. Karen M. Warkentin of the University of Texas reported the first known instance in which egg hatching is induced by a predator. The red-eyed tree frog (Agalychnis callidryas) of Middle America lays eggs on leaves overhanging temporary ponds. At hatching, which occurs 5 to 10 days after the eggs are laid, the tadpoles drop into the water below. The primary predator of the eggs is the cat-eyed snake (Leptodeira septentrionalis), whereas fish and other animals prey on the tadpoles. Older hatchlings were found to be less vulnerable to aquatic predators than younger ones; therefore, later hatching favoured the survival of tadpoles. In experiments comparing the timing of hatching, most undisturbed eggs hatched late, but eggs under attack by snakes were seen to hatch within minutes, sometimes seconds. The escaping tadpoles entered the water at a more vulnerable stage but managed to avoid egg predators. Such plasticity in an animal's life history can be highly advantageous. A hatching age that changes with conditions to maximize survivorship should increase fitness in a variable environment. (J. WHITFIELD GIBBONS) This updates the articles animal behaviour; biology; mammal; evolution, theory of.