India known as the Republic of India, is a country in South Asia. It is the seventh largest country by area and with more than 1.3 billion people, it is the second most populous country as well as the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, the Bay of Bengal on the southeast, it shares land borders with Pakistan to the west. In the Indian Ocean, India is in the vicinity of Sri Lanka and the Maldives, while its Andaman and Nicobar Islands share a maritime border with Thailand and Indonesia; the Indian subcontinent was home to the urban Indus Valley Civilisation of the 3rd millennium BCE. In the following millennium, the oldest scriptures associated with Hinduism began to be composed. Social stratification, based on caste, emerged in the first millennium BCE, Buddhism and Jainism arose. Early political consolidations took place under the Gupta empires. In the medieval era, Zoroastrianism and Islam arrived, Sikhism emerged, all adding to the region's diverse culture.
Much of the north fell to the Delhi Sultanate. The economy expanded in the 17th century in the Mughal Empire. In the mid-18th century, the subcontinent came under British East India Company rule, in the mid-19th under British Crown rule. A nationalist movement emerged in the late 19th century, which under Mahatma Gandhi, was noted for nonviolent resistance and led to India's independence in 1947. In 2017, the Indian economy was the world's sixth largest by nominal GDP and third largest by purchasing power parity. Following market-based economic reforms in 1991, India became one of the fastest-growing major economies and is considered a newly industrialised country. However, it continues to face the challenges of poverty, corruption and inadequate public healthcare. A nuclear weapons state and regional power, it has the second largest standing army in the world and ranks fifth in military expenditure among nations. India is a federal republic governed under a parliamentary system and consists of 29 states and 7 union territories.
A pluralistic and multi-ethnic society, it is home to a diversity of wildlife in a variety of protected habitats. The name India is derived from Indus, which originates from the Old Persian word Hindush, equivalent to the Sanskrit word Sindhu, the historical local appellation for the Indus River; the ancient Greeks referred to the Indians as Indoi, which translates as "The people of the Indus". The geographical term Bharat, recognised by the Constitution of India as an official name for the country, is used by many Indian languages in its variations, it is a modernisation of the historical name Bharatavarsha, which traditionally referred to the Indian subcontinent and gained increasing currency from the mid-19th century as a native name for India. Hindustan is a Middle Persian name for India, it was introduced into India by the Mughals and used since then. Its meaning varied, referring to a region that encompassed northern India and Pakistan or India in its entirety; the name may refer to either the northern part of India or the entire country.
The earliest known human remains in South Asia date to about 30,000 years ago. Nearly contemporaneous human rock art sites have been found in many parts of the Indian subcontinent, including at the Bhimbetka rock shelters in Madhya Pradesh. After 6500 BCE, evidence for domestication of food crops and animals, construction of permanent structures, storage of agricultural surplus, appeared in Mehrgarh and other sites in what is now Balochistan; these developed into the Indus Valley Civilisation, the first urban culture in South Asia, which flourished during 2500–1900 BCE in what is now Pakistan and western India. Centred around cities such as Mohenjo-daro, Harappa and Kalibangan, relying on varied forms of subsistence, the civilization engaged robustly in crafts production and wide-ranging trade. During the period 2000–500 BCE, many regions of the subcontinent transitioned from the Chalcolithic cultures to the Iron Age ones; the Vedas, the oldest scriptures associated with Hinduism, were composed during this period, historians have analysed these to posit a Vedic culture in the Punjab region and the upper Gangetic Plain.
Most historians consider this period to have encompassed several waves of Indo-Aryan migration into the subcontinent from the north-west. The caste system, which created a hierarchy of priests and free peasants, but which excluded indigenous peoples by labeling their occupations impure, arose during this period. On the Deccan Plateau, archaeological evidence from this period suggests the existence of a chiefdom stage of political organisation. In South India, a progression to sedentary life is indicated by the large number of megalithic monuments dating from this period, as well as by nearby traces of agriculture, irrigation tanks, craft traditions. In the late Vedic period, around the 6th century BCE, the small states and chiefdoms of the Ganges Plain and the north-western regions had consolidated into 16 major oligarchies and monarchies that were known as the mahajanapadas; the emerging urbanisation gave rise to non-Vedic religious movements, two of which became independent religions. Jainism came into prominence during the life of Mahavira.
Buddhism, based on the teachings of Gautama Buddha, attracted followers from all social classes excepting the middle
Roraima is the northernmost and least populated state of Brazil, located in the Amazon region. It borders the states of Pará, as well as the nations of Venezuela and Guyana; the population is 450,000 and the capital is Boa Vista. Roraima is the Brazilian state with 15 in total; the climate of Roraima is tropical with an annual mean temperature of 26°C. The state's southern part is located in the Amazon rainforest, while the north has open grassland fields, there is a small strip of savanna to the east; the state is rich in mineral deposits - gold, cassiterite, bauxite and copper. Many of these deposits are located in indigenous reserves, illegal mining has resulted in frequent conflicts with the native population the Yanomami and the Macuxi and allied groups; the Monte Roraima National Park is located around one of the highest mountains of both Venezuela and Brazil, the highest in Guyana, a 2,875 m high tepui known as Monte Roraima. Only a small fraction of the mountain is in Brazilian territory and the highest point of the Brazilian part is at 2,734 metres.
Except for the higher mountains where the climate is cooler but wet, Roraima has an equatorial climate. This is a type of tropical climate in which there is no dry season – all months have mean precipitation values of at least 60 mm, it is found at latitudes within five degrees of the equator – which are dominated by the Intertropical Convergence Zone. The equatorial climate is denoted Af in the Köppen climate classification. Tropical rainforest is the natural vegetation in equatorial regions. Since the beginnings of the 16th century, the region now considered the state of Roraima was disputed territory, because of its rich mineral reserves, it was sought by the Spanish, Portuguese and English until the beginning of the last century. But in 1943, together with a section from the state of Amazonas, the Federal Government created the territory of Rio Branco, which became Roraima in 1962. In 1988, Roraima became a state by decision of the National Congress; the name of the state was taken from Mount Roraima, whose name comes from the Pemon words “roroi” and “ma”.
One of the main archaeological site is the Pedra Pintada, with ancient rock art and engravings. According to the IBGE of 2007, there were 405,000 people residing in the state; the population density was 1.8 inh./km². Urbanization: 80.3%. The latest PNAD data reveal the following numbers: 278,000 Brown people, 81,000 White people, 29,000 Black people, 15,000 Asian or Amerindian people. Ethnic groups found in Roraima include: Amerindians, Africans, Spanish and Lebanese; the Brazilian Indian Agency, estimates the state's indigenous population at 30,715. The largest indigenous groups are the better-known Yanomami. Much of the state's indigenous population lives in several large recognized indigenous reserves and a number of smaller ones, totalling 46.13% of the land area of the state. Vehicles: 187,209 Mobile phones: 148,000 Telephones: 67,000 Cities: 15; the service sector is the largest component of GDP at 87.5%, followed by the industrial sector at 8.7%. Agriculture represents 3.8%, of GDP. Roraima exports: wood 74%, leather 22.6%.
Share of the Brazilian economy: 0.1%. Portuguese is the official national language, thus the primary language taught in schools, but English and Spanish are part of the official high school curriculum. Universidade Federal de Roraima; the city's major teams are: Atlético Roraima Clube. The passenger terminal and apron were all enlarged, a separate taxiway was built; the airport has the capacity to receive 675,000 passengers a year. BR-174; the blue of the flag represents the pure air and the sky of Roraima, the white strip symbolizes peace, the green to the right represents the forests and fields. The star - symbolizing the state in the national flag of Brazil - is yellow, which symbolizes the mineral resources of the state; the red line in bottom stands for the equator. The flag was designed by the artist Mário Barreto, was adopted by Law No.133 of June 14, 1996. Official Website Brazilian Tourism Portal
Natural capital is the world's stock of natural resources, which includes geology, air and all living organisms. Some natural capital assets provide people with free goods and services called ecosystem services. Two of these make human life possible, it is an extension of the economic notion of capital to goods and services provided by the natural environment. For example, a well-maintained forest or river may provide an indefinitely sustainable flow of new trees or fish, whereas over-use of those resources may lead to a permanent decline in timber availability or fish stocks. Natural capital provides people with essential services, like water catchment, erosion control and crop pollination by insects, which in turn ensure the long-term viability of other natural resources. Since the continuous supply of services from the available natural capital assets is dependent upon a healthy, functioning environment, the structure and diversity of habitats and ecosystems are important components of natural capital.
Methods, called'natural capital asset checks', help decision-makers understand how changes in the current and future performance of natural capital assets will impact on human well-being and the economy. Natural capital is one approach to ecosystem valuation which revolves around the idea, in contrast to traditional economics, that non-human life produces essential resources. Thus, ecological health is essential to the sustainability of the economy. In Natural Capitalism: Creating the Next Industrial Revolution the author claims that the global economy is within a larger economy of natural resources and ecosystem services that sustain us. In order to continue to reap the benefits of our natural environment, we need to recognize the importance of natural capital within the economy. According to the authors, the "next industrial revolution" depends on the espousal of four central strategies: "the conservation of resources through more effective manufacturing processes, the reuse of materials as found in natural systems, a change in values from quantity to quality, investing in natural capital, or restoring and sustaining natural resources."In a traditional economic analysis of the factors of production, natural capital would be classified as "land" distinct from traditional "capital".
The historical distinction between "land" and "capital" defined “land” as occurring with a fixed supply, whereas “capital”, as defined referred only to man-made goods. It is however, misleading to view "land" as if its productive capacity is fixed, because natural capital can be improved or degraded by the actions of man over time. Moreover, natural capital yields benefits and goods, such as timber or food, which can be harvested by humans; these benefits are similar to those realized by owners of infrastructural capital which yields more goods, such as a factory which produces automobiles just as an apple tree produces apples. The term'natural capital' was first used in 1973 by E. F. Schumacher in his book Small Is Beautiful and is identified with Herman Daly, Robert Costanza, the Biosphere 2 project, the Natural Capitalism economic model of Paul Hawken, Amory Lovins, Hunter Lovins, it has begun to be used by politicians, notably Ralph Nader, Paul Martin Jr. and agencies of the UK government, including its Natural Capital Committee and the London Health Observatory.
All users of the term differentiate natural from man-made or infrastructural capital in some way. Indicators adopted by United Nations Environment Programme's World Conservation Monitoring Centre and the Organisation for Economic Co-operation and Development to measure natural biodiversity use the term in a more specific way. According to the OECD, natural capital is “natural assets in their role of providing natural resource inputs and environmental services for economic production” and is “generally considered to comprise three principal categories: natural resources stocks and ecosystems.” Within the international community the basic principle is not controversial, although much uncertainty exists over how best to value different aspects of ecological health, natural capital and ecosystem services. Full-cost accounting, triple bottom line, measuring well-being and other proposals for accounting reform include suggestions to measure an "ecological deficit" or "natural deficit" alongside a social and financial deficit.
It is difficult to measure such a deficit without some agreement on methods of valuation and auditing of at least the global forms of natural capital. Ecologists are teaming up with economists to measure and express values of the wealth of ecosystems as a way of finding solutions to the biodiversity crisis; some researchers have attempted to place a dollar figure on ecosystem services such as the value that the Canadian boreal forest's contribution to global ecosystem services. If ecologically intact, the boreal forest has an estimated value of US$3.7 trillion. The boreal forest ecosystem is one of the planet's great atmospheric regulators and it stores more carbon than any other biome on the planet; the annual value for ecological services of the Boreal Forest is estimated at US$93.2 billion, or 2.5 greater than the annual value of resource extraction. The economic value of 17 ecosystem services for the entire biosphere has an estimated average value of US$33 trillion per year; these ecological economic values are not included in calculations of national income accounts, the GDP and they have no price attributes because they exist outside of the global markets.
Indigenous peoples known as first peoples, aboriginal peoples or native peoples, are ethnic groups who are the original settlers of a given region, in contrast to groups that have settled, occupied or colonized the area more recently. Groups are described as indigenous when they maintain traditions or other aspects of an early culture, associated with a given region. Not all indigenous peoples share this characteristic, as many have adopted substantial elements of a colonizing culture, such as dress, religion or language. Indigenous peoples may be settled in a given region or exhibit a nomadic lifestyle across a large territory, but they are historically associated with a specific territory on which they depend. Indigenous societies are found in every inhabited climate continent of the world. Since indigenous peoples are faced with threats to their sovereignty, economic well-being and their access to the resources on which their cultures depend, political rights have been set forth in international law by international organizations such as the United Nations, the International Labour Organization and the World Bank.
The United Nations has issued a Declaration on the Rights of Indigenous Peoples to guide member-state national policies to the collective rights of indigenous peoples, such as culture, identity and access to employment, health and natural resources. Estimates put the total population of indigenous peoples from 220 million to 350 million. International Day of the World's Indigenous Peoples is celebrated on 9 August each year; the adjective indigenous was used to describe animals and plant origins. During the late twentieth century, the term Indigenous people began to be used to describe a legal category in indigenous law created in international and national legislations, it is derived from the Latin word indigena, based on the root gen-'to be born' with an archaic form of the prefix in'in'. Notably, the origins of the term indigenous is not related in any way to the origins of the term Indian which until was applied to indigenous peoples of the Americas. Any given people, ethnic group or community may be described as indigenous in reference to some particular region or location that they see as their traditional indigenous land claim.
Other terms used to refer to indigenous populations are aboriginal, original, or first. The use of the term peoples in association with the indigenous is derived from the 19th century anthropological and ethnographic disciplines that Merriam-Webster Dictionary defines as "a body of persons that are united by a common culture, tradition, or sense of kinship, which have common language and beliefs, constitute a politically organized group". James Anaya, former Special Rapporteur on the Rights of Indigenous Peoples, has defined indigenous peoples as "living descendants of pre-invasion inhabitants of lands now dominated by others, they are culturally distinct groups that find themselves engulfed by other settler societies born of forces of empire and conquest". They form at present non-dominant sectors of society and are determined to preserve and transmit to future generations their ancestral territories, their ethnic identity, as the basis of their continued existence as peoples, in accordance with their own cultural patterns, social institutions and legal system.
The International Day of the World's Indigenous People falls on 9 August as this was the date of the first meeting in 1982 of the United Nations Working Group of Indigenous Populations of the Subcommission on Prevention of Discrimination and Protection of Minorities of the Commission on Human Rights. Throughout history, different states designate the groups within their boundaries that are recognized as indigenous peoples according to international or national legislation by different terms. Indigenous people include people indigenous based on their descent from populations that inhabited the country when non-indigenous religions and cultures arrived—or at the establishment of present state boundaries—who retain some or all of their own social, economic and political institutions, but who may have been displaced from their traditional domains or who may have resettled outside their ancestral domains; the status of the indigenous groups in the subjugated relationship can be characterized in most instances as an marginalized, isolated or minimally participative one, in comparison to majority groups or the nation-state as a whole.
Their ability to influence and participate in the external policies that may exercise jurisdiction over their traditional lands and practices is frequently limited. This situation can persist in the case where the indigenous population outnumbers that of the other inhabitants of the region or state. In a ground-breaking 1997 decision involving the Ainu people of Japan, the Japanese courts recognised their claim in law, stating that "If one minority group lived in an area prior to being ruled over by a majority group and preserved its distinct ethnic culture after being ruled over by the majority group, while another came to live in an area ruled over by a majority after consenting to the majority rule, it must be recognised that it is only natural that the distinct ethnic culture of the former group requires greater consideration."In Russia, definition of "indigenous peoples" is contested referring to a number of population (less
Biodiversity refers to the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic and ecosystem level. Terrestrial biodiversity is greater near the equator, the result of the warm climate and high primary productivity. Biodiversity is not distributed evenly on Earth, is richest in the tropics; these tropical forest ecosystems cover less than 10 percent of earth's surface, contain about 90 percent of the world's species. Marine biodiversity is highest along coasts in the Western Pacific, where sea surface temperature is highest, in the mid-latitudinal band in all oceans. There are latitudinal gradients in species diversity. Biodiversity tends to cluster in hotspots, has been increasing through time, but will be to slow in the future. Rapid environmental changes cause mass extinctions. More than 99.9 percent of all species that lived on Earth, amounting to over five billion species, are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described.
More in May 2016, scientists reported that 1 trillion species are estimated to be on Earth with only one-thousandth of one percent described. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037 and weighs 50 billion tonnes. In comparison, the total mass of the biosphere has been estimated to be as much as 4 TtC. In July 2016, scientists reported identifying a set of 355 genes from the Last Universal Common Ancestor of all organisms living on Earth; the age of the Earth is about 4.54 billion years. The earliest undisputed evidence of life on Earth dates at least from 3.5 billion years ago, during the Eoarchean Era after a geological crust started to solidify following the earlier molten Hadean Eon. There are microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia. Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old meta-sedimentary rocks discovered in Western Greenland. More in 2015, "remains of biotic life" were found in 4.1 billion-year-old rocks in Western Australia.
According to one of the researchers, "If life arose quickly on Earth.. it could be common in the universe."Since life began on Earth, five major mass extinctions and several minor events have led to large and sudden drops in biodiversity. The Phanerozoic eon marked a rapid growth in biodiversity via the Cambrian explosion—a period during which the majority of multicellular phyla first appeared; the next 400 million years included repeated, massive biodiversity losses classified as mass extinction events. In the Carboniferous, rainforest collapse led to a great loss of animal life; the Permian–Triassic extinction event, 251 million years ago, was the worst. The most recent, the Cretaceous–Paleogene extinction event, occurred 65 million years ago and has attracted more attention than others because it resulted in the extinction of the dinosaurs; the period since the emergence of humans has displayed an ongoing biodiversity reduction and an accompanying loss of genetic diversity. Named the Holocene extinction, the reduction is caused by human impacts habitat destruction.
Conversely, biodiversity positively impacts human health in a number of ways, although a few negative effects are studied. The United Nations designated 2011–2020 as the United Nations Decade on Biodiversity. 1916 - The term biological diversity was used first by J. Arthur Harris in "The Variable Desert," Scientific American, JSTOR 6182: "The bare statement that the region contains a flora rich in genera and species and of diverse geographic origin or affinity is inadequate as a description of its real biological diversity." 1975 - The term natural diversity was introduced 1980 - Thomas Lovejoy introduced the term biological diversity to the scientific community in a book.. It became used. 1985 -The contracted form biodiversity was coined by W. G. Rosen 1985 - The term "biodiversity" appears in the article, "A New Plan to Conserve the Earth's Biota" by Laura Tangley. 1988 - The term biodiversity first appeared in a publication. The present - the term has achieved widespread use. "Biodiversity" is most used to replace the more defined and long established terms, species diversity and species richness.
Biologists most define biodiversity as the "totality of genes and ecosystems of a region". An advantage of this definition is that it seems to describe most circumstances and presents a unified view of the traditional types of biological variety identified: taxonomic diversity ecological diversity morphological diversity functional diversity This multilevel construct is consistent with Datman and Lovejoy. An explicit definition consistent with this interpretation was first given in a paper by Bruce A. Wilcox commissioned by the International Union for the Conservation of Nature and Natural Resources for the 1982 World National Parks Conference. Wilcox's definition was "Biological diversity is the variety of life forms...at all levels of biologi
In business, overhead or overhead expense refers to an ongoing expense of operating a business. Overheads are the expenditure which cannot be conveniently traced to or identified with any particular cost unit, unlike operating expenses such as raw material and labor. Therefore, overheads cannot be associated with the products or services being offered, thus do not directly generate profits. However, overheads are still vital to business operations as they provide critical support for the business to carry out profit making activities. For example, overhead costs such as the rent for a factory allows workers to manufacture products which can be sold for a profit; such expenses are incurred for output and not for particular work order. Overheads are very important cost element along with direct materials and direct labor. Overheads are related to accounting concepts such as fixed costs and indirect costs. Overhead expenses are all costs on the income statement except for direct labor, direct materials, direct expenses.
Overhead expenses include accounting fees, insurance, legal fees, labor burden, repairs, taxes, telephone bills, travel expenditures, utilities. There are two types of business overheads: administrative overheads and manufacturing overheads. Administrative overheads include items such as utilities, strategic planning, various supporting functions; these costs are treated as overheads due to the fact that they aren't directly related to any particular function of the organization nor does it directly result in generating any profits. Instead, these costs take on the role of supporting all of the business' other functions. Universities charge administrative overhead rates on research. In the U. S. the average overhead rate is 52%, spent on building operation, administrative salaries and other areas not directly tied to research. Academics have argued against these charges. For example, Benjamin Ginsberg showed how overhead rates are used to subsidize ballooning administrative salaries and building depreciation, neither of which directly benefit research.
An article written by Joshua Pearce in Science argued that overhead accounting practices hurt science by removing funds from research and discouraging the use of less-expensive open source hardware. He went into detail on the accounting showing how millions were wasted each year on overhead cash grabs by university administrators in ZME Science; this includes monthly and annual salaries that are agreed upon. They are considered overheads as these costs must be paid regardless of sales and profits of the company. In addition, salary differs from wage as salary is not affected by working hours and time, therefore will remain constant. In particular, this would more apply to more senior staff members as they are signed to longer tenure contracts, meaning that their salaries are more predetermined; this includes office equipment such as printer, fax machine, refrigerator, etc. They are equipment that do not directly result in sales and profits as they are only used for supporting functions that they can provide to business operations.
However, equipment can vary between administrative overheads and manufacturing overheads based on the purpose of which they are using the equipment. For example, for a printing company a printer would be considered a manufacturing overhead; this includes the cost of hiring external audit firms on behalf of the company. This would not apply if company has own audit plans. Due to regulations and necessary annual audits to ensure a satisfactory work place environment, these costs cannot be avoided. Since these costs do not contribute directly to sales, they are considered as indirect overheads. Although in most cases necessary, these costs can sometimes be reduced. Many companies provide usage of company cars as a perk for their employees. Since these cars do not contribute directly to sales and profits, they are considered an overhead. Similar company perks that are a one-off or constant payment such as partner contract fees with a gym will fall under administrative overheads; this will include company-paid business arrangements.
As well as refreshments and entertainment fees during company gatherings. Although one might argue that these costs motivate workers to become more productive and efficient, the majority of economists agree that these costs do not directly contribute to sales and profits, therefore shall be categorized as an administrative overhead. Despite these costs occurring periodically and sometimes without prior preparation, they are one-off payments and are expected to be within the company's budget for travel and entertainment. Manufacturing overheads are all costs endured by a business, within the physical platform in which the product or service is created. Difference between manufacturing overheads and administrative overheads is that manufacturing overheads are categorized within a factory or office in which the sale takes place. Whilst administrative overheads is categorized within some sort of back-office or supporting office. Although there are cases when the two physical buildings may overlap, it is the usage of the overheads that separates them.
Although the general concept is identical to the example under administrative overheads, the key difference is the role of the employee. In the case of manufacturing overheads, employees would have roles such as maintenance personnel, manufacturing m
West Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Guinea, Guinea-Bissau, Ivory Coast, Mali, Niger, Senegal, Sierra Leone and Togo, as well as the United Kingdom Overseas Territory of Saint Helena and Tristan da Cunha; the population of West Africa is estimated at about 362 million people as of 2016, at 381,981,000 as of 2017, to which 189,672,000 are female, 192,309,000 male. Studies of human mitochondrial DNA suggest that all humans share common ancestors from Africa, originated in the southwestern regions near the coastal border of Namibia and Angola at the approximate coordinates 12.5° E, 17.5°S with a divergence in the migration path around 37.5°E, 22.5°N near the Red Sea. A particular haplogroup of DNA, haplogroup L2, evolved between 87,000 and 107,000 years ago or approx. 90,000 YBP. Its age and widespread distribution and diversity across the continent makes its exact origin point within Africa difficult to trace with any confidence, however an origin for several L2 groups in West or Central Africa seems with the highest diversity in West Africa.
Most of its subclades are confined to West and western-Central Africa. Because of the large numbers of West Africans enslaved in the Atlantic slave trade, most African Americans are to have mixed ancestry from different regions of western Africa; the history of West Africa can be divided into five major periods: first, its prehistory, in which the first human settlers arrived, developed agriculture, made contact with peoples to the north. Early human settlers from northern Holocene societies arrived in West Africa around 12,000 B. C. At Gobero, the Kiffian, who were hunters of tall stature, lived during the green Sahara between 10,000 and 8,000 years ago; the Tenerian, who were a more built people that hunted and herded cattle, lived during the latter part of the green Sahara 7,000 to 4,500 years ago. Sedentary farming began in, or around the fifth millennium B. C, as well as the domestication of cattle. By 1500 B. C, ironworking technology allowed an expansion of agricultural productivity, the first city-states formed.
Northern tribes developed walled settlements and non-walled settlements that numbered at 400. In the forest region, Iron Age cultures began to flourish, an inter-region trade began to appear; the desertification of the Sahara and the climatic change of the coast cause trade with upper Mediterranean peoples to be seen. The domestication of the camel allowed the development of a trans-Saharan trade with cultures across the Sahara, including Carthage and the Berbers. Local leather and gold contributed to the abundance of prosperity for many of the following empires; the development of the region's economy allowed more centralized states and civilizations to form, beginning with Dhar Tichitt that began in 1600 B. C. followed by Djenné-Djenno beginning in 300 B. C; this was succeeded by the Ghana Empire that first flourished between the 9th and 12th centuries, which gave way to the Mali Empire. In current-day Mauritania, there exist archaeological sites in the towns of Tichit and Oualata that were constructed around 2000 B.
C. and were found to have originated from the Soninke branch of the Mandé peoples, according to their tradition, originate from Aswan, Egypt. Based on the archaeology of city of Kumbi Saleh in modern-day Mauritania, the Mali empire came to dominate much of the region until its defeat by Almoravid invaders in 1052. Three great kingdoms were identified in Bilad al-Sudan by the ninth century, they included Ghana and Kanem. The Sosso Empire sought to fill the void, but was defeated by the Mandinka forces of Sundiata Keita, founder of the new Mali Empire; the Mali Empire continued to flourish for several centuries, most under Sundiata's grandnephew Musa I, before a succession of weak rulers led to its collapse under Mossi and Songhai invaders. In the 15th century, the Songhai would form a new dominant state based on Gao, in the Songhai Empire, under the leadership of Sonni Ali and Askia Mohammed. Meanwhile, south of the Sudan, strong city states arose in Igboland, such as the 10th-century Kingdom of Nri, which helped birth the arts and customs of the Igbo people, Bono in the 12th century, which culminated in the formation the all-powerful Akan Empire of Ashanti, while Ife rose to prominence around the 14th century.
Further east, Oyo arose as the dominant Yoruba state and the Aro Confederacy as a dominant Igbo state in modern-day Nigeria. The Kingdom of Nri was a West African medieval state in the present-day southeastern Nigeria and a subgroup of the Igbo people; the Kingdom of Nri was unusual in the history of world government in that its leader exercised no military power over his subjects. The kingdom existed as a sphere of religious and political influence over a third of Igboland and was administered by a priest-king called as an Eze Nri; the Eze Nri managed trade and diplomacy on behalf of the Nri people and possessed divine authority in religious matters. The Oyo Empire was a Yoruba empire of what is today Western and North c