ASIA

world's largest and most diverse continent, covering about 30 percent of the land area on Earth. The mainland is situated between latitude 78 N and 1 N and longitude 26 E and 170 W; it extends for about 6,000 miles (9,700 km) from east to west and 4,000 miles (6,500 km) from north to south. The continent is bounded on the north by the Arctic Ocean, on the east by the Pacific Ocean, and on the south by the Indian Ocean; the western boundary, with Europe, runs roughly north-south along the eastern Ural Mountains, the Zhem River, the Caspian Sea, the Kuma-Manych Depression, the Black Sea, the Aegean Sea, the Mediterranean Sea, the Suez Canal, and the Red Sea. The coastline of continental Asia is some 39,000 miles (62,750 km) long. The islands of Sri Lanka and Taiwan and the archipelagoes of Indonesia, the Philippines, and Japan also form part of Asia, which is the most populous of the continents. in antiquity, the first and westernmost Roman province in Asia Minor, stretching at its greatest extent from the Aegean coast in the west to a point beyond Philomelium (modern Aksehir) in the east and from the Sea of Marmara in the north to the strait between Rhodes and the mainland in the south. The province was first constituted when Attalus III, king of Pergamum, bequeathed his dominions to the Romans in 133 BC. At that time the province contained many different communities at different stages of development. The province was rich in natural resources, and its dyestuffs and woolen textiles were famous. Under the Roman Republic, however, its prosperity was ruined by commercial exploitation, taxation, and war, so that its advance toward Hellenization and urbanization, begun under the Seleucid and Pergamene kings, was impeded. Recovery under the empire was rapid. Asia was a peaceful province and was under senatorial jurisdiction, governed from Ephesus by a proconsul of consular rank (under the republic the governor had usually been a former praetor). The provincial assembly, called the koinon of Asia, to which the cities sent representatives, met annually in different cities, chose the officials known as Asiarchs, passed resolutions, made appeals, and sent deputations on provincial matters. The great cities of Asia were leading educational and cultural centres in the Eastern Roman Empire. Important Christian communities and bishoprics grew up within the province, as did important heresies, such as Montanism. During the 3rd and 4th centuries AD the province lost much of its economic importance as the development of the Balkan provinces, military needs, and the founding of Constantinople turned the empire's main lines of communication away from the Aegean and toward the northwest. Yet the province's reserves of products and manpower and its relative immunity from devastation made it an important factor in the survival of the Eastern Roman Empire. Under Diocletian (reigned AD 284305) it was divided into seven smaller provinces. world's largest and most diverse continent, covering about 30 percent of the land area on Earth. The eastern four-fifths of the giant Eurasian landmass, Asia is more a geographic term than a homogeneous continent. It has the greatest range of land elevation of any continent, has the longest coastline, is subject overall to the world's widest climatic extremes, and, consequently, produces the most varied forms of vegetation and animal life on Earth. In addition, the peoples of Asia have established the broadest pattern of human adaptation found on any of the continents. The name Asia is ancient, and its origin has been variously explained. The Greeks used it to designate the lands situated to the east of their homeland. It is also believed that the name may be derived from the Assyrian word asu, meaning east. Another possible explanation is that it was originally a local name given to the plains of Ephesus and gradually extended to include Anatolia (contemporary Asia Minor, which is the western extreme of mainland Asia) and the rest of the continent. Asia is bounded by the Arctic Ocean on the north, the Pacific Ocean on the east, the Indian Ocean on the south, the inland seas of the Atlantic Oceanthe Mediterranean and the Blackon the southwest, and Europe on the west. Asia is separated from North America to the northeast by the Bering Strait and from Australia to the southeast by the mingled waters of the Indian and Pacific oceans. The Isthmus of Suez unites Asia with Africa, and it is generally agreed that the Suez Canal forms the border between them. Two narrow straits, the Bosporus and the Dardanelles, separate Anatolia from the Balkan Peninsula. The land boundary between Asia and Europe is a historical and cultural construct that is subject to various interpretations; only as a matter of agreement is it tied to a specific borderline. The most convenient geographic boundaryone that has been adopted by most geographersis a line that runs south from the Arctic Ocean along the eastern slope of the Ural Mountains and then turns southwest along the Zhem River to the northern shore of the Caspian Sea; west of the Caspian, the boundary follows the Kuma-Manych Depression to the Sea of Azov and the Kerch Strait. The total area of Asia, including the Caucasian isthmus and excluding the island of New Guinea, amounts to about 17,226,000 square miles (44,614,000 square km). The islandsSevernaya Zemlya, the New Siberian Islands, Wrangel Island, Sakhalin, the Kurils, Japan, the Ryukyus, Taiwan, Hainan, the Philippines, Indonesia and insular Malaysia, the Andaman and Nicobar islands, Sri Lanka, and Cyprusaccount for about 1,240,000 square miles (3,210,000 square km) of the total (although New Guinea is mentioned occasionally in this article, it generally is not considered to be a part of Asia). The farthest terminal points of the Asian mainland are Cape Chelyuskin in north-central Siberia, Russia (7743 N), to the north; the tip of the Malay Peninsula, Cape Piai, or Bulus (116 N), to the south; Cape Baba in Turkey (264 E) to the west; and Cape Dezhnyov, or East Cape (16940 W), in northeastern Siberia, overlooking the Bering Strait, to the east. Asia has the highest average elevation of the continents and contains the sharpest relief. The highest peak in the world, Mount Everest, which is 29,035 feet (8,850 metres) high; the lowest place on the Earth's land surface, the Dead Sea, which averages about 1,312 feet (400 metres) below sea level; and the world's deepest continental trough, occupied by Lake Baikal, which is 5,315 feet (1,620 metres) deep and whose bottom lies at 3,822 feet (1,165 metres) below sea level, are all located in Asia. These physiographic extremes and the overall predominance of mountain belts and plateaus are the result of Asia's prolonged and intense geologic activity. Asia is the youngest of the continents; broadly speaking, it consists of several ancient platform cores, which over time accumulated immense quantities of material around them and were subjected to a series of collisions with one another that resulted in uplifting along the zones of collision. Asia's coastlinesome 39,000 miles (62,800 km) in lengthis, variously, high and mountainous, low and alluvial, terraced as a result of the land being uplifted, or drowned where the land has subsided. The specific features of the coastline in some areasespecially in the east and southeastare the result of active volcanism; of thermal abrasion (resulting from a combination of action by sea breakers and of thawing) by the subterranean fossilized ice (consisting of fossil ice, subsurface ice, and ice-formed rock), as in northeastern Siberia; and of coral building, as in the areas to the south and southeast. The mountain systems of Central Asia not only have provided the continent's great rivers with water from their melting snows but also have formed a forbidding natural barrier that has influenced the movement of peoples into the area. Migration has been possible only through mountain passes. As a result, the historic movement of population has been broadly from the arid zones of Central Asia through the mountain passes into the Indo-Pakistan subcontinent, from China through Southeast Asia to modern Indonesia and Malaysia, and from the Arabian Peninsula and from India across the Bay of Bengal into Indonesia and Malaysia. The Korean and Japanese people and, to a lesser extent, the Chinese have remained ethnologically more homogeneous than the populations of other Asian countries. Also as a result of this configuration, Asia's population is unevenly distributed. There is a concentration of population in western Asia as well as great concentrations in the Indo-Pakistan subcontinent and the eastern half of China and appreciable concentrations in the Pacific borderlands and on the islands; but vast areas of Central and North Asia have remained sparsely populated. Nonetheless, Asia, the most populous of the continents, contains almost three-fifths of the world's people. Asia is the birthplace of all the world's major religionsBuddhism, Christianity, Hinduism, Islam, and Judaismand of many minor ones. Of these, only Christianity developed primarily outside Asia; it exerts little influence on the continent, though many Asian countries have Christian minorities. Buddhism has had a greater impact outside its birthplace in India and is prevalent in various forms in China, Korea, Japan, the Southeast Asian countries, and Sri Lanka. Islam has spread out of Arabia eastward to South and Southeast Asia, as well as westward and southward to Africa. Hinduism has been mostly confined to the Indian subcontinent. Chakravarthi V. Narasimhan Yury Konstantinovich Yefremov The Editors of the Encyclopdia Britannica This article treats the physical and human geography of Asia, followed by discussion of geographic features of special interest. For detailed discussion of the peoples of Asia, see the article Asian people. For discussion of individual countries of the continent, see specific articles by namee.g., China, India, and Japan. For discussion of major cities of the continent, see specific articles by namee.g., Bangkok, Istanbul, Peking (Beijing), and Seoul. The principal treatment of Asian historical and cultural development is contained in the articles on Asian countries, regions, and cities and in the articles Palestine, history of and Islamic world. Related topics are discussed in articles on religion (e.g., Buddhism, Hinduism, and Islam) and arts and literature (e.g., Chinese literature, Japanese literature, Central Asian arts, Southeast Asian arts, and South Asian arts). Additional reading General works Useful atlases of the regions and countries of Asia include Tbinger Atlas des Vorderen Orients (1977 ), a major publication on the Middle East, comprising a geographic atlas covering contemporary physical geography and a historical atlas arranged chronologically, with text in both German and English; Richard Ulack and Gyula Pauer, Atlas of Southeast Asia (1989); Joseph E. Schwartzberg et al. (eds.), A Historical Atlas of South Asia (1978, reissued with additional material, 1992); The Population Atlas of China (1987), compiled by the Population Census Office of the Chinese government; The National Economic Atlas of China (1994); Chang Chi-yun (Chi-yun Chang) (ed.), National Atlas of China, 2nd ed., 5 vol. (196467); P.J.M. Geelan and D.C. Twitchett (eds.), The Times Atlas of China (1974); A. Ebato and K. Watanabe (eds.), Atlas of Japan: Physical, Economic, and Social, 2nd rev. ed. (1974); The National Atlas of Japan, rev. ed. (1990), compiled by the Geographical Survey Institute of the Ministry of Construction; S.P. Chatterjee (ed.), National Atlas of India (1968 ); and A Social and Economic Atlas of India (1987). Up-to-date statistics on demographic, social, and economic indicators are available in Asia Yearbook; and the World Development Report (annual), published for the World Bank; as well as in such major annuals as The Asia & Pacific Review; The Europa World Year Book; The Far East and Australasia; The Middle East and North Africa; and Economic and Social Survey of Asia and the Pacific, published by the United Nations. George Thomas Kurian, Encyclopedia of the Third World, 4th ed., 3 vol. (1992), offers a compendium of data on the developing countries. The Editors of the Encyclopdia Britannica Geologic history Works dealing with the general geology of Asia are few, and most are outdated, but some contain information that is still useful (including references to older literature) and give an idea of the evolution of the concepts, such as L. de Launay, La Gologie et les richesses minrales de l'Asie (1911); Emile Argand, Tectonics of Asia (1977; originally published in French, 1924); and Kurt Leuchs, Geologie von Asien, 2 vol. (193537). Structure and tectonic evolution are studied in A.L. Ianshin (ed.), Tektonika Evrazii (1966); Peter Molnar and Paul Tapponnier, Cenozoic Tectonics of Asia: Effects of a Continental Collision, Science, 189(4201):419426 (Aug. 8, 1975), the classic paper on the subject; Li Chnyu (Chn-y Li) et al., Explanatory Notes to the Tectonic Map of Asia (1982); International Geological Congress, Tectonics of Asia (1984); A. Miyashiro, Tectonic and Petrologic Aspects of Asia, Memoir of the Geological Society of China, 4:131 (1981); A.M. Cell Sengr, The Cimmeride Orogenic System and the Tectonics of Eurasia (1984), and Tectonic Subdivisions and Evolution of Asia, Bulletin of the Technical University of Istanbul, 40:355435 (1987); and S. Maruyama et al., Mesozoic and Cenozoic Evolution of Asia, in Zvi Ben-Avraham (ed.), The Evolution of the Pacific Ocean Margins (1989, pp. 7599). Magmatic and metamorphic development is examined in J.L. Whitford-Stark, A Survey of Cenozoic Volcanism on Mainland Asia (1987); and V.S. Sobolev et al. (eds.), Metamorphic Complexes of Asia (1982; originally published in Russian, 1977). Duncan R. Derry et al., World Atlas of Geology and Mineral Deposits (1980), provides a graphic summary of the mineral wealth of Asia and its relation to its geology.The following are regional studies. Treatments of North Asia include Geology of the USSR (1984), one of the colloquiums of the 27th International Geological Congress; Victor E. Khain, Geology of the USSR, vol. 1, Old Cratons and Paleozoic Fold Belts (1985); L.P. Zonenshayn, M.I. Kuzmin, and L.M. Natalov, Phanerozoic Palinspastic Reconstructions for the USSR, Geotectonics, 21(6):487502 (1988); and A.V. Peive et al. (eds.), Tektonika severnoi Evrazii (1980), a volume of explanatory material to the tectonic map of northern Eurasia. East Asia is analyzed in Thomas W.C. Hilde and Seiya Uyeda (eds.), Geodynamics of the Western Pacific-Indonesian Region (1983); Robert Orr Whyte et al. (eds.), The Evolution of the East Asian Environment, 2 vol. (1984); Asahiko Taira and Masayuki Tashiro (eds.), Historical Biogeography and Plate Tectonic Evolution of Japan and Eastern Asia (1987); Masaru Kono and B. Clark Burchfiel (eds.), Tectonics of Eastern Asia and Western Pacific Continental Margin (1990); and J. Angelier (ed.), Geodynamic Evolution of the Eastern Eurasian Margin (1990), the last two published as special issues of Tectonophysics, respectively, vol. 181 and 183. Discussions of Southeast Asia include Warren Hamilton, Tectonics of the Indonesian Region (1979); Dennis E. Hayes (ed.), The Tectonic and Geologic Evolution of Southeast Asian Seas and Islands, 2 vol. (198083); Eric Buffetaut, Jean-Jacques Jaeger, and Jean-Claude Rage, Palographie de l'Inde, du Tibet, et du Sud-Est asiatique (1985); Pham Quoc Tuong et al. (eds.), First Conference on Geology of Indochina (1986); Charles S. Hutchinson, Geological Evolution of South-East Asia (1988); and Dennis E. Hayes (compiler), A Geophysical Atlas of the East and Southeast Asian Seas (1978). South and Southwest Asia are addressed by Harsh K. Gupta and Frances M. Delany (eds.), Zagros, Hindu Kush, Himalaya: Geodynamic Evolution (1981); K. Nakazawa and J.M. Dickins (eds.), The Tethys: Her Paleogeography and Paleobiogeography from Paleozoic to Mesozoic (1985); Peter Molnar, A Review of Geophysical Constraints on the Deep Structure of the Tibetan Plateau, the Himalaya, and the Karakoram, and Their Tectonic Implications, in R.M. Shackleton, J.F. Dewey, and B.F Windley (eds.), Tectonic Evolution of the Himalayas and Tibet (1988), pp. 3388; and A.M. Cell Sengr et al. (eds.), Tectonic Evolution of the Tethyan Region (1989). A.M. Cell Sengr The land Broad surveys of physical features of the continent as a whole or of large parts of it include Dudley Stamp, Asia: A Regional and Economic Geography, 12th ed. (1967); Pierre Pfeffer, Asia: A Natural History (1968); N.A. Gvozdetskiy and N.I. Mikhailov, Physical Geography of the USSR: Asiatic Part, trans. from Russian (1971); Iu.K. Efremov, Priroda moei strany (1985), covering the natural history of the former U.S.S.R.; W.B. Fisher, The Middle East: A Physical, Social, and Regional Geography, 7th rev. ed. (1978); C.S. Pichamuthu, Physical Geography of India, 4th ed. (1980); O.H.K. Spate et al., India and Pakistan: A General and Regional Geography, 3rd rev. ed. (1967); Encyclopedia of New China (1987); and Jin-bee Ooi, Peninsular Malaysia, new ed. (1976). Specific ecological characteristics are addressed in R. Misra, Indian Savannas, in Franois Bourlire (ed.), Tropical Savannas (1983), pp. 151166; Charles A. Reed (ed.), Origins of Agriculture (1977); and Natural Resources of Humid Tropical Asia (1974), a UNESCO research report.Overviews of environmental zones include T.C. Whitmore, Tropical Rain Forests of the Far East, 2nd ed. (1984); Tropical Forest Ecosystems (1978), a UNESCO report; H. Walter et al., The Deserts of Central Asia, in Neil E. West (ed.), Temperate Deserts and Semi-Deserts (1983), pp. 193236; Vaclav Smil, The Bad Earth: Environmental Degradation in China (1984); and Qu Geping, Deserts in China and Their Prevention and Control, Mazingira, 4(2):7479 (1980). Climatic patterns are examined in William C. Brice (ed.), The Environmental History of the Near and Middle East Since the Last Ice Age (1978); U. Schweinfurth, H. Flohn, and M. Domrs, Studies in the Climatology of South Asia (1970); and Jen-hu Chang, Atmospheric Circulation Systems and Climates (1972). Plant life is treated in Arnold Newman, Tropical Rainforest: A World Survey of Our Most Valuable and Endangered Habitat with a Blueprint for Its Survival (1990); and Harry G. Champion and S.K. Seth, A Revised Survey of the Forest Types of India (1968). Aleksandr Maximovich Ryabchikov Nina Nikolaevna Alexeeva The people Marvin Harris, Culture, People, Nature: An Introduction to General Anthropology, 5th ed. (1988), puts the peoples of Asia in comparative ethnic/racial context. A useful traditional overview of monsoonal Asia's peoples, languages, and religions is presented in J.E. Spencer and William L. Thomas, Asia, East by South, 2nd ed. (1971). Among many works on comparative religions, S.A. Nigosian, World Faiths (1990), provides a cogent and thoughtful description of all of Asia's major and a number of minor religions; John Y. Fenton et al., Religions of Asia, 2nd ed. (1988), gives a good explanation of East and South Asian religions; and Joseph M. Kitagawa (ed.), The Religious Traditions of Asia (1989), collects essays of leadings scholars on the religions of South, Southeast, East, and Central Asia.Clarence Maloney, Peoples of South Asia (1974), remains a standard on the social and cultural geography of the subcontinent. Other useful works on the region include David E. Sopher (ed.), An Exploration of India: Geographical Perspectives on Society and Culture (1980); and Allen G. Noble and Ashok K. Dutt (eds.), India: Cultural Patterns and Processes (1982). Probably the best cultural work on East Asia is Albert Kolb, East Asia (1971; originally published in German, 1963). Clifton W. Pannell (ed.), East Asia: Geographical and Historical Approaches to Foreign Area Studies (1983), is a later collection of essays. Judith Banister, China's Changing Population (1987), comprehensively describes the large and varied population and is based on census data. Among the more detailed and thorough economic and social geographies of Southeast Asia is Donald W. Fryer, Emerging Southeast Asia: A Study in Growth and Stagnation, 2nd ed. (1979). E.H.G. Dobby, Southeast Asia, 11th ed. (1973), remains a standard on the region. Ashok K. Dutt (ed.), Southeast Asia: Realm of Contrasts, 3rd rev. ed. (1985), offers more historical as well as standard social and economic geography.Peter Beaumont, Gerald H. Blake, and J. Malcolm Wagstaff, The Middle East, 2nd ed. (1988), surveys the human geography of Southwest Asia. Somewhat broader in regional scope is Mushtaqur Rahman, Muslim World (1987), which includes topics of physical geography. Akbar S. Ahmed, Discovering Islam: Making Sense of Muslim History and Society (1988), perceptively focuses on the people and historical developments.Urbanization and the growth of great cities as key human processes transforming the lives of millions of Asians are analyzed in Frank J. Costa et al. (eds.), Urbanization in Asia: Spatial Dimensions and Policy Issues (1989); and Norton Ginsburg, Bruce Koppel, and T.G. McGee (eds.), The Extended Metropolis: Settlement Transition in Asia (1991). A good brief overview of the variable trends among a number of countries is presented in Gavin W. Jones, Structural Change and Prospects for Urbanization in Asian Countries (1983). Clifton W. Pannell The economy General economic surveys include Joseph E. Spencer, Oriental Asia: Themes Toward a Geography (1973); Denis Dwyer (ed.), South East Asian Development: Geographical Perspectives (1990); Tom Kemp, Industrialization in the Non-Western World, 2nd ed. (1989); and Robert A. Scalapino, Seizaburo Sato, and Jusuf Wanandi (eds.), Asian Economic DevelopmentPresent and Future (1985). Michael Smith et al., Asia's New Industrial World (1985), explores industrial growth in Japan, South Korea, Singapore, and Indonesia. Individual countries are the focus of David Friedman, The Misunderstood Miracle: Industrial Development and Political Change in Japan (1988); and David S.G. Goodman (ed.), China's Regional Development (1989). Economic aspects of Asian agriculture are studied in Y. Atal, Swidden Cultivation in Asia: The Need for a New Approach, Nature and Resources, 20(3):1926 (1984), comparing practices in India, Indonesia, Malaysia, the Philippines, and Thailand; Francesca Bray, The Rice Economies: Technology and Development in Asian Societies (1986); and Harry T. Oshima, Economic Growth in Monsoon Asia (1987), a useful comparative study. Thomas R. Leinbach Geologic history Asia is not only the Earth's largest but also its youngest and structurally most complicated continent. Although Asia's evolution began almost four billion years ago, more than half of it remains seismically active, and new continental material is currently being produced in the island-arc systems that surround it to the east and southeast. In such places, new land is continuously emerging and is added to the bulk of the continent by episodic collisions of the island arcs with the mainland. By virtue of its enormous size and relative youth, Asia contains many of the morphological extremes of the Earth's land surfacesuch as its highest and lowest points, longest coastline, and largest area of continental shelf. Asia's immense mountain ranges, vast continental plains and basins, and varied coastline have had a profound effect on the course of human history. The fact that Asia produces about half of the world's petroleum and coal, in addition to being a significant contributor to the global production of many minerals (e.g., about three-fifths of the world's tin), heavily underlines the importance of its geology for the welfare of the world's population. General considerations Tectonic framework The morphology of Asia masks an extremely complex geologic history that predates the active deformations largely responsible for the existing landforms. Tectonic units (regions identified by similarity of style and origin of geologic structures contained in them) that are defined on the basis of active structures in Asia are not identical to those defined on the basis of its fossil (i.e., now inactive) structures. It is therefore convenient to discuss the tectonic framework of Asia in terms of two separate maps, one showing its paleotectonic (i.e., older tectonic) units and the other displaying its neotectonic (new and presently active) units. Since continents are formed as a consequence of the motions of tectonic plates, the Earth's geologic history is dominated by the opening and closing of oceans. Oceans commonly open by riftingby tearing a continent asunderand close along subduction zones, which are inclined seismic planes along which ocean floors sink and are assimilated into the Earth's mantle. Ocean closure culminates in continental collision and may involve the accretion of vast tectonic collages, including small continental fragments, island arcs, large deposits of sediment, and occasional fragments of ocean-floor material. In defining the units to draw Asia's paleotectonic map, it is useful to outline such accreted objects and the lines, or sutures, along which they are opposed. Continuing convergence following collision may significantly distort the colliding continents, especially by faulting, and thus disrupt further an already assembled tectonic collage along new, secondary lines. Postcollisional disruption also may reactivate some of the old tectonic lines (such as sutures). These secondary structures dominate and define the neotectonic units of Asia. It should be mentioned, however, that most former continental collisions also have led to the generation of secondary structures that add to the structural diversity of the continent. The paleotectonic units of Asia are divided into two first-order classes: continental nuclei and orogenic (mountain-building) zones. The continental nuclei consist of platforms that were stabilized mostly in Precambrian time (between 3.8? billion and 540 million years ago) and covered largely by little-disturbed sedimentary rocks; included in this designation are the Angaran (or East Siberian), Indian, and Arabian platforms. There are also several smaller platforms that were deformed to a greater extent than the larger units and are called paraplatforms; these include the North China (or Sino-Korean) and Yangtze paraplatforms, the Kontum block, and the North Tarim fragment (also called Serindia). The orogenic zones consist of large tectonic collages that were accreted around the continental nuclei. Recognized zones are the Altaids, the Tethysides (further subdivided into the Cimmerides and the Alpides), and the circum-Pacific belt. (It should be noted that the Alpides and circum-Pacific belt are partially of neotectonic origin.) The Precambrian continental nuclei were formed by essentially the same plate tectonic processes that constructed the later orogenic zones, but it is best to treat them separately for three reasons. First, the nuclei occupy only about one-fourth of the area of Asia, and less than one-third of this area (i.e., less than 10 percent of Asia's total) consists of exposed Precambrian rocks that enable geologists to study their development. Second, Precambrian rocks are extremely poor in fossils, which makes global or even regional correlations difficult. Finally, during most of Phanerozoic time (i.e., the past 540 million years), the nuclei have behaved as singular entities and have acted as hosts around which the tectonic collages making up the Phanerozoic orogenic zones have accumulated. The paleotectonic evolution of Asia terminated some 50 million years ago as a result of the collision of India with Eurasia. Asia's subsequent neotectonic development has been responsible for largely disrupting the continent's preexisting fabric. The first-order neotectonic units of Asia are Stable Asia, the Arabian and Indian cratons, the Alpide plate boundary zone, and the island arcs and marginal basins. The economy General considerations While the economies of most Asian countries can be characterized as developing, there is enormous variation among them. This variation results from several causes: population size and characteristics, the history of development and external contact, resource base, and political structure. There is no typical economy. Japan is by far the most advanced country in Asia, whether measured in terms of economic or social indicators. At an intermediate stage of development are the newly industrializing countries (NICs), which include Hong Kong, Singapore, South Korea, and Taiwan, as well as Israel and the oil-rich nations of the Middle East. Further down the economic ladder are the countries of the Association of Southeast Asian Nations (ASEAN; Malaysia, Thailand, Philippines, Indonesia, Brunei, as well as the NIC Singapore), the South Asian countries, and China. Finally, among the poorest are the socialist countries of Southeast Asia and such nations as Afghanistan and Nepal. The explanation for these varying degrees of development is complex and multifaceted. In many countries economic development initially was stimulated by colonial rule, which provided improvements in transportation and communications, administration, health care, and the exploitation of agricultural and mineral resources. Too often, however, such development produced a reliance on a limited number of commodities that were tied to fluctuating world market prices. The lack of expertise and capital after many of these countries became independent resulted in economic stagnation, sometimes under misdirected leadership. In other situations, the availability of resources, such as oil, provided a driving economic force. In addition, political systems and ideological policies, as well as internal conflicts, have shaped economic development. A key variable in assessing development advancement is human capital; the level of education, the well-being of the citizenry, and an environment that encourages economic progress are important. Agriculture has remained a critical aspect of the economies of Asia. It is still the traditional source of livelihood for the great majority of the population and for many countries the source of most of their income. Despite the fact that there has been steady growth in food production, it is estimated that throughout developing Asia the increase in production per capita has been marginal in light of concurrent population growth. The dominant methods by which the major grain crops are produced remain traditional and labour-intensive. Crop yields vary greatly throughout Asia. For example, rice production per acre in Bangladesh is a third that of South Korea. Only about a third of Asia's land is arable, and it has been increasingly difficult to expand production by extending the amount of cultivated land. Major efforts to increase production have occurred through the so-called green revolution, which involved four major inputs: the use of chemical fertilizers and pesticides, irrigation, the introduction of high-yielding hybrid seed strains, and mechanization. These efforts have had a significant positive impact in many areas but a negative impact in others. Too often, wealthier farmers have had access to such inputs while poorer farmers have not. There has been much debate on the continuing impact of the green revolution, but efforts also have continued in these programs. A major barrier to further agricultural development has been the uneven distribution of land. This problem has been particularly acute in the poorer countries of Asia. While governments have made concerted efforts to produce workable land-reform programs, progress has been slow; this has been particularly conspicuous in the Indian subcontinent and the Philippines. In the socialist countries, land reform has been attempted through collectivization, but success in terms of production has been limited at best. A major development in many of the economies of Asia has been structural change and diversification. Since the 1960s the growth in industry and services, with a concomitant decline in the agricultural contribution to gross domestic product, has been conspicuous. The examples of China, India, Indonesia, Malaysia, Thailand, and Turkey are noteworthy. Most striking is the growth of the NICs. Despite their small size and the lack of raw materials, economic development has been produced by flexible resource allocation, export-oriented production, and a willingness to accept direct foreign investment. In this respect, the pattern of Japanese investment in Asia has been significant because of its major role in determining structures and patterns of production and trade. While heavy industry has grown, especially in the larger market economies of Asia, the most significant development has been the growth of light industry in the smaller countries. This has been based on local, overseas-Chinese, and Western multinational enterprises. A major shortcoming associated with this development has been an increased dependence on Western markets and a heightened vulnerability to protectionism. Yet such industries also have served critical local agricultural and industrial needs. Finally, in addition to formal industry, a significant informal sector of services and enterprises has emerged in response to local demands with respect to products and labour creation. Asian economic interdependence has grown significantly since the 1960s as a product of trade, investment, and skill flows. Yet this interdependence is immature and has produced strains between the wealthier and poorer countries. Formal organization of the regional economy remains relatively weak, although ASEAN has worked reasonably well. Resources The immensity of the continent and its geologic diversity explain the mineral wealth of Asia, which includes reserves of almost every important mineral. Abundant reserves of coal, oil, natural gas, uranium, iron, bauxite, and other ores are either being exploited or awaiting development; much wealth also remains to be surveyed. The inaccessibility of some of these reserves, however, sometimes has constituted a barrier to their exploitation. The land Animal life The Himalayas, stretching from east to west, form a barrier that largely prevents the movement of animals southward or northward. Thus, Asia north of the Himalayas, with parts of western Asia and most of East Asia, belongs to the Palaearctic (Old World) subregion of the Holarctic zoogeographic region (roughly, the Northern Hemisphere). Asia south of the Himalayas is called the Oriental, or Indian, region. The boundary dividing these zones east and west of the Himalayas is not well marked, however, as there the mountain chains often have a north-south trend facilitating migration of animals between them. Asian faunal habitats have been subjected to the same disruption from human activities that have affected the continent's vegetation, particularly in regions of extremely dense population ( e.g., the great Indian river valleys and the plains and lowlands of eastern and southern China). Asia's vastness and its numerous remote regions, however, have made it possible for many animal species to live practically undisturbed by human activity. Nonetheless, the threat of extinction remains for many species, most notably for the giant panda of China and the Sumatran rhinoceros and orangutan of Southeast Asia. The Palaearctic region A distinction can be made between the animal life of the tundra in the north and that of the adjacent taiga farther south. The taiga in turn merges into the steppes, which have their own distinctive forms of animal life. Finally, the fauna of East and Southwest Asia have their own distinguishing characteristics. The land Plant life An immense range of vegetation is found in Asia, the result of the continent's wide diversity of latitude, altitude, and climate. Natural conditions, however, are not entirely responsible for the associations of trees, plants, and grasses of Asia; natural landscapes have been transformed by more than eight millennia of farming and other human activities. The geographic pattern of vegetation North and Central Asia Thawed surface of the permafrost on the tundra in summer, Taymyr Peninsula, Siberia. The natural landscape has been least affected by man in sparsely populated North Asia. Vast plains, continentality, and the nearness of the Arctic Ocean explain the presence here of a zone of tundracold, treeless plains with permanently frozen subsoilsimilar to that found in the European part of Russia and in Canada. In more flourishing parts, the tundra has a discontinuous covering of lichens, mosses, sedges, rushes, some grasses, cushions of bilberries, and dwarf trees of willow and birch; in the far north, lichens grow on favourable hillsides. Because of the greater number of hours of daylight during the summer months, when the Arctic Circle receives the same amount of light energy as the tropics, the tundra at this season is covered with bright flowers. Nevertheless, climate conditions are extreme. In Severnaya Zemlya, along the Arctic coast, thawing begins in May and frosts begin in August, although in some years frosts may occur at night throughout the short summer. The soil never thaws below a depth of two or three feet; consequently, hollows are badly drained and turn into peat bogs. Windy conditions speed up evaporation, and the frozen soil cannot absorb water to compensate for this, so that surface drought often results in wind erosion and the removal of sediments deposited by annual riverine floods. The tundra belt extends still farther south on higher ground. In the Arctic, tundra in the Ural Mountains begins at about 3,000 feet, but at latitude 53 N it begins at 4,250 feet. Tundra extends over large areas of the Chersky, Verkhoyansk, and Kamchatka mountain ranges. The taiga zonea belt of coniferous forestbegins south of the tundra, after a transitional zone of wooded tundra and forest galleries found along streams between the tundra-covered watersheds. Taiga, although essentially coniferous, is mixed with hardy deciduous trees such as aspen and birch; there are sections of grass and shrub steppe in the drier zones. Larches account for more than a third of the vast Siberian forest, while pines cover about a fourth and spruces a tiny fraction. The geographic distribution of particular types of vegetation is determined chiefly by climate. Spruce, for example, unable to survive temperatures below -36 F (-38 C), is not found east of the Yenisey River. The taiga has a thin undergrowth of cranberries and bilberries, and there are numerous extensive peat bogs. In western Siberia, broad-leaved deciduous forest also does not extend east of the Yeniseywhere it gives way to the coniferous forests of central Siberiabut it reappears in eastern Siberia near the Sea of Okhotsk; poplars, birches, and alders are numerous there, as are various conifers and larches. Forests around the Ussuri River include maples, ashes, walnuts, elms, and lindens, in addition to species already mentioned. South of the western Siberian forests are found forest-steppes, with forest galleries lining the rivers. Forest-steppe and meadow-steppe vegetation is predominant on the Manchurian Plain. The steppe zone runs from Kazakstan through the Altai Mountains to the Greater Khingan Range. Herbaceous cover of feather grass, rootstock grasses, and sagebrush is utilized for grazing. Farther south, discontinuous semidesert and desert vegetation predominates. To the east, the steppes stretch toward the southern part of the Ordos Desert, forming the transition to the monsoonal landscapes of eastern China. Tibet, which is chiefly dry and cold, has a scattered vegetation of halophilic (salt-tolerant) bushes and species of the genus Artemisia. The land Climate Air masses and wind patterns The enormous expanse of Asia and its abundance of mountain barriers and inland depressions have resulted in great differences among regions in existing conditions of solar radiation, atmospheric circulation, and climate as a whole. A continental climate, associated with large landmasses and characterized by an extreme annual range of temperature, prevails over a large part of Asia. Air reaching Asia from the Atlantic Ocean, after passing over Europe or Africa, has had time to be transformed into continental air. As a result of the prevalent easterly movement of the air masses, as well as the isolating effect of the marginal mountain ranges, the influence of sea air