Misplaced Pages

#942057

113-848: The river basin is famous for its large number of early hominid fossils and archeological findings such as early stone tools, leading to its inclusion on the UNESCO World Heritage List in 1980. The Omo River forms through the confluence of the Gibe River , by far the largest total tributary of the Omo River, and the Wabe River , the largest left-bank tributary of the Omo at 8°19′N 37°28′E  /  8.317°N 37.467°E  / 8.317; 37.467 . Given their sizes, lengths and courses one might consider both

226-415: A multi-layered network of cooperating, distinct, or even competing social groups – from families and peer groups to corporations and political states . As such, social interactions between humans have established a wide variety of values, social norms , languages , and traditions (collectively termed institutions ), each of which bolsters human society . Humans are also highly curious , with

339-668: A theory of mind . The human mind is capable of introspection , private thought , imagination , volition , and forming views on existence . This has allowed great technological advancements and complex tool development through complex reasoning and the transmission of knowledge to subsequent generations through language . Humans have had a dramatic effect on the environment . They are apex predators , being rarely preyed upon by other species. Human population growth , industrialization, land development, overconsumption and combustion of fossil fuels have led to environmental destruction and pollution that significantly contributes to

452-505: A French expedition. The most significant finds were made later, between 1967 and 1975, by an international archaeological team. This team located a number of different items, including the jawbone of an Australopithecus man, estimated at some 2.5 million years old. Archeologists have also found fossil fragments of Olduwan hominids from the early Pleistocene era and up to the Pliocene era. Quartz tools have been located with some of

565-443: A consequence of better nutrition, healthcare, and living conditions. The average mass of an adult human is 59 kg (130 lb) for females and 77 kg (170 lb) for males. Like many other conditions, body weight and body type are influenced by both genetic susceptibility and environment and varies greatly among individuals. Humans have a far faster and more accurate throw than other animals. Humans are also among

678-419: A few other places), saw the emergence of agriculture and permanent human settlement ; in turn, this led to the development of civilization and kickstarted a period of continuous (and ongoing) population growth and rapid technological change . Since then, a number of civilizations have risen and fallen, while a number of sociocultural and technological developments have resulted in significant changes to

791-463: A great capacity for altering their habitats by means of technology, irrigation , urban planning , construction, deforestation and desertification . Human settlements continue to be vulnerable to natural disasters , especially those placed in hazardous locations and with low quality of construction. Grouping and deliberate habitat alteration is often done with the goals of providing protection, accumulating comforts or material wealth, expanding

904-612: A higher body fat percentage. At puberty , humans develop secondary sex characteristics . Females are capable of pregnancy , usually between puberty, at around 12 years old, and menopause , around the age of 50. As omnivorous creatures, they are capable of consuming a wide variety of plant and animal material, and have used fire and other forms of heat to prepare and cook food since the time of Homo erectus . Humans can survive for up to eight weeks without food and several days without water . Humans are generally diurnal , sleeping on average seven to nine hours per day. Childbirth

1017-475: A human can lose personhood (such as by going into a persistent vegetative state ). Humans are apes ( superfamily Hominoidea ). The lineage of apes that eventually gave rise to humans first split from gibbons (family Hylobatidae) and orangutans (genus Pongo ), then gorillas (genus Gorilla ), and finally, chimpanzees and bonobos (genus Pan ). The last split, between the human and chimpanzee–bonobo lineages, took place around 8–4 million years ago, in

1130-692: A large S- bend then resumes its southerly course to Lake Turkana. According to materials published by the Ethiopian Central Statistical Agency , the Omo-Bottego River is 760 kilometres (470 mi) long. In its course the Omo-Bottego has a total fall of about 700 metres (2,300 ft) from the confluence of the Gibe and Wabe rivers at 1,060 metres (3,480 ft) to 360 metres (1,180 ft) at lake-level, and

1243-581: A more barrel-shaped chests in contrast to the funnel shape of other apes, an adaptation for bipedal respiration. Apart from bipedalism and brain size, humans differ from chimpanzees mostly in smelling , hearing and digesting proteins . While humans have a density of hair follicles comparable to other apes, it is predominantly vellus hair , most of which is so short and wispy as to be practically invisible. Humans have about 2 million sweat glands spread over their entire bodies, many more than chimpanzees, whose sweat glands are scarce and are mainly located on

SECTION 10

#1732765538943

1356-504: A much clearer picture of life at the time. Between the 8th and 6th century BCE, Europe entered the classical antiquity age, a period when ancient Greece and ancient Rome flourished. Around this time other civilizations also came to prominence. The Maya civilization started to build cities and create complex calendars . In Africa, the Kingdom of Aksum overtook the declining Kingdom of Kush and facilitated trade between India and

1469-613: A remarkably long adolescence, not being weaned for several years, and not becoming fully mature for eight to thirteen years in most species (longer in orangutans and humans). As a result, females typically give birth only once every few years. There is no distinct breeding season. Gorillas and chimpanzees live in family groups of around five to ten individuals, although much larger groups are sometimes noted. Chimpanzees live in larger groups that break up into smaller groups when fruit becomes less available. When small groups of female chimpanzees go off in separate directions to forage for fruit,

1582-451: A result, humans are a cosmopolitan species found in almost all regions of the world, including tropical rainforest , arid desert , extremely cold arctic regions , and heavily polluted cities; in comparison, most other species are confined to a few geographical areas by their limited adaptability. The human population is not, however, uniformly distributed on the Earth 's surface, because

1695-639: A similar species. Migrating out of Africa , they gradually replaced and interbred with local populations of archaic humans. Multiple hypotheses for the extinction of archaic human species such as Neanderthals include competition, violence , interbreeding with Homo sapiens , or inability to adapt to climate change . Humans began exhibiting behavioral modernity about 160,000–60,000 years ago. For most of their history, humans were nomadic hunter-gatherers. The Neolithic Revolution , which began in Southwest Asia around 13,000 years ago (and separately in

1808-515: A simple linear or branched progression but involved interbreeding between related species . Genomic research has shown that hybridization between substantially diverged lineages was common in human evolution. DNA evidence suggests that several genes of Neanderthal origin are present among all non sub-Saharan-African populations, and Neanderthals and other hominins, such as Denisovans , may have contributed up to 6% of their genome to present-day non sub-Saharan-African humans. Human evolution

1921-451: A successful labor increased significantly during the 20th century in wealthier countries with the advent of new medical technologies. In contrast, pregnancy and natural childbirth remain hazardous ordeals in developing regions of the world, with maternal death rates approximately 100 times greater than in developed countries. Both the mother and the father provide care for human offspring, in contrast to other primates, where parental care

2034-481: A theory of mind. This is also the case for some New World monkeys outside the family of great apes, as, for example, the capuchin monkeys . However, even without the ability to test whether early members of the Hominini (such as Homo erectus , Homo neanderthalensis , or even the australopithecines) had a theory of mind, it is difficult to ignore similarities seen in their living cousins. Orangutans have shown

2147-622: A tunnel entrance 7°55′27″N 37°23′16″E  /  7.92417°N 37.38778°E  / 7.92417; 37.38778  ( Gilgel Gibe II Power Station headrace tunnel entrance ) on the Gilgel Gibe River in a run-of-river scheme. The tunnel entrance is sitting downstream of the Gilgel Gibe I Dam also on the Gilgel Gibe River with which it forms a hydroelectric cascade. The Gibe III Hydroelectric dam

2260-741: A varied use of the word "hominid" over time. The original meaning of the term referred to only humans and their closest relatives—what is now the modern meaning of the term " hominin ". The meaning of the taxon Hominidae changed gradually, leading to a modern usage of "hominid" that includes all the great apes including humans. A number of very similar words apply to related classifications: A cladogram indicating common names (cf. more detailed cladogram below ): Hylobatidae    gibbons Pongo abelii Pongo tapanuliensis Pongo pygmaeus Gorilla gorilla Gorilla beringei Pan troglodytes Pan paniscus Homo sapiens      humans Hominidae

2373-406: A wide variety of plant and animal material. Human groups have adopted a range of diets from purely vegan to primarily carnivorous . In some cases, dietary restrictions in humans can lead to deficiency diseases ; however, stable human groups have adapted to many dietary patterns through both genetic specialization and cultural conventions to use nutritionally balanced food sources. The human diet

SECTION 20

#1732765538943

2486-419: Is Oreopithecus , from the fossil-rich coal beds in northern Italy and dated to 9 million years ago. Molecular evidence indicates that the lineage of gibbons (family Hylobatidae), the "lesser apes", diverged from that of the great apes some 18–12 million years ago, and that of orangutans (subfamily Ponginae) diverged from the other great apes at about 12 million years. There are no fossils that clearly document

2599-734: Is 2.1.2.3 2.1.2.3 . Human teeth and jaws are markedly smaller relative to body size compared to those of other apes. This may be an adaptation not only to the extensive use of tools, which has supplanted the role of jaws in hunting and fighting, but also to eating cooked food since the end of the Pleistocene . Although most living species are predominantly quadrupedal , they are all able to use their hands for gathering food or nesting materials, and, in some cases, for tool use. They build complex sleeping platforms, also called nests, in trees to sleep in at night, but chimpanzees and gorillas also build terrestrial nests, and gorillas can also sleep on

2712-568: Is "the most destructive dam under construction in Africa." The project would condemn "half a million of the region's most vulnerable people to hunger and conflict." A group of international campaigners launched an online petition against Ethiopia's dam project over human rights concerns. However, Azeb Asnake, project manager of Gibe III for the government power provider, said that a mitigation measure has been prepared in case something happens. Apart from this, Asnake predicted no adverse consequence from

2825-511: Is 38 weeks, but a normal pregnancy can vary by up to 37 days. Embryonic development in the human covers the first eight weeks of development; at the beginning of the ninth week the embryo is termed a fetus . Humans are able to induce early labor or perform a caesarean section if the child needs to be born earlier for medical reasons. In developed countries, infants are typically 3–4 kg (7–9 lb) in weight and 47–53 cm (19–21 in) in height at birth. However, low birth weight

2938-624: Is a 243 metres (797 ft) high roller-compacted concrete dam with an associated hydropower plant on the Omo River in Ethiopia . It is the largest hydropower plant in Ethiopia with a power output of about 1870 Megawatt (MW), thus more than doubling total installed capacity in Ethiopia from its 2007 level of 814 MW. A controversy has ensued over its construction, with several NGOs forming a campaign to oppose it. According to Terri Hathaway, director of International Rivers ' Africa programme, Gibe III

3051-485: Is a mixture of the two parental sets. Among the 23 pairs of chromosomes, there are 22 pairs of autosomes and one pair of sex chromosomes . Like other mammals, humans have an XY sex-determination system , so that females have the sex chromosomes XX and males have XY. Genes and environment influence human biological variation in visible characteristics, physiology, disease susceptibility and mental abilities. The exact influence of genes and environment on certain traits

3164-424: Is a population decline in the winter months of this realm. Humans established nation-states in the other seven realms, such as South Africa , India , Russia , Australia , Fiji , United States and Brazil (each located in a different biogeographical realm). By using advanced tools and clothing , humans have been able to extend their tolerance to a wide variety of temperatures, humidities , and altitudes. As

3277-438: Is also important geologically and archaeologically. Over 50,000 fossils have been identified from the lower valley, including 230 hominid fossils dating to the Pliocene and Pleistocene . Fossils belonging to the genera Australopithecus and Homo have been found at several archaeological sites, as well as tools made from quartzite , the oldest of which date back to about 2.4 million years ago. When they were discovered, it

3390-402: Is characterized by a number of morphological , developmental , physiological , and behavioral changes that have taken place since the split between the last common ancestor of humans and chimpanzees . The most significant of these adaptations are hairlessness , obligate bipedalism, increased brain size and decreased sexual dimorphism ( neoteny ). The relationship between all these changes

3503-456: Is common in developing countries, and contributes to the high levels of infant mortality in these regions. Compared with other species, human childbirth is dangerous, with a much higher risk of complications and death. The size of the fetus's head is more closely matched to the pelvis than in other primates. The reason for this is not completely understood, but it contributes to a painful labor that can last 24 hours or more. The chances of

Omo River - Misplaced Pages Continue

3616-585: Is consequently a rapid stream in its upper reaches, being broken by the Kokobi and other falls, and navigable only for a short distance above where it empties into Lake Turkana, one of the lakes of the Gregory Rift . The Spectrum Guide to Ethiopia describes it as a popular site for white-water rafting in September and October, when the river is still high from the rainy season. Its most important tributary

3729-421: Is dangerous, with a high risk of complications and death . Often, both the mother and the father provide care for their children, who are helpless at birth . Humans have a large, highly developed, and complex prefrontal cortex , the region of the brain associated with higher cognition. Humans are highly intelligent and capable of episodic memory ; they have flexible facial expressions, self-awareness , and

3842-479: Is generally aging, with the median age around 40 years. In the developing world , the median age is between 15 and 20 years. While one in five Europeans is 60 years of age or older, only one in twenty Africans is 60 years of age or older. In 2012, the United Nations estimated that there were 316,600 living centenarians (humans of age 100 or older) worldwide. Humans are omnivorous , capable of consuming

3955-443: Is inherited only from the mother, geneticists have concluded that the last female common ancestor whose genetic marker is found in all modern humans, the so-called mitochondrial Eve , must have lived around 90,000 to 200,000 years ago. Most human reproduction takes place by internal fertilization via sexual intercourse , but can also occur through assisted reproductive technology procedures. The average gestation period

4068-408: Is mostly done by the mother. Helpless at birth , humans continue to grow for some years, typically reaching sexual maturity at 15 to 17 years of age. The human life span has been split into various stages ranging from three to twelve. Common stages include infancy , childhood , adolescence , adulthood and old age . The lengths of these stages have varied across cultures and time periods but

4181-541: Is much greater than that between male and female chimpanzees. This enables gorilla males to physically dominate female gorillas more easily. In both chimpanzees and gorillas, the groups include at least one dominant male, and young males leave the group at maturity. Due to the close genetic relationship between humans and the other great apes, certain animal rights organizations, such as the Great Ape Project , argue that nonhuman great apes are persons and, per

4294-521: Is not well understood. While no humans – not even monozygotic twins  – are genetically identical, two humans on average will have a genetic similarity of 99.5%-99.9%. This makes them more homogeneous than other great apes, including chimpanzees. This small variation in human DNA compared to many other species suggests a population bottleneck during the Late Pleistocene (around 100,000 years ago), in which

4407-536: Is the Gibe River ; smaller tributaries include the Wabi , Denchya , Gojeb , Mui and Usno rivers. The Omo-Bottego River formed the eastern boundaries for the former kingdoms of Janjero , and Garo . The Omo also flows past the Mago and Omo National Parks , which are known for their wildlife. Many animals live near and on the river, including hippopotamuses , crocodiles and puff adders . The entire Omo river basin

4520-460: Is the only one that has occurred within the past fifty years. The recent drop in the level of Lake Turkana, which is generally recognized to receive about ninety percent of its waters from the Omo River's inflow, has already caused a rise in salinity level. The increased size of the delta, now about 1,300 square kilometres (500 sq mi) in extent, has provided lands for recessional cultivation and pasture for cattle and other domestic livestock of

4633-445: Is the subject of ongoing debate. Hylobatidae ( gibbons ) Pongo abelii Pongo tapanuliensis Pongo pygmaeus Gorilla gorilla Gorilla beringei Pan troglodytes Pan paniscus Homo sapiens (humans) Until about 12,000 years ago, all humans lived as hunter-gatherers . The Neolithic Revolution (the invention of agriculture ) first took place in Southwest Asia and spread through large parts of

Omo River - Misplaced Pages Continue

4746-654: Is typified by an unusually rapid growth spurt during adolescence. Human females undergo menopause and become infertile at around the age of 50. It has been proposed that menopause increases a woman's overall reproductive success by allowing her to invest more time and resources in her existing offspring, and in turn their children (the grandmother hypothesis ), rather than by continuing to bear children into old age. The life span of an individual depends on two major factors, genetics and lifestyle choices. For various reasons, including biological/genetic causes, women live on average about four years longer than men. As of 2018 ,

4859-479: Is vital to the indigenous groups that live along it. The flood brings fertile silt and inundates the banks with water, making river bank cultivation possible. The diverse peoples along the lower Omo—which include the Turkana , Dassanach , Hamer , Nyangatom , Karo, Kwegu , Mursi , Bodi , and Me'en —derive a great portion of their food supply from flood retreat cultivation. The large and destructive flood of 2006

4972-548: The British Empire expanded to become the world's largest empire . A tenuous balance of power among European nations collapsed in 1914 with the outbreak of the First World War , one of the deadliest conflicts in history. In the 1930s, a worldwide economic crisis led to the rise of authoritarian regimes and a Second World War , involving almost all of the world's countries . The war's destruction led to

5085-580: The Caral–Supe civilization is the oldest complex civilization in the Americas. Astronomy and mathematics were also developed and the Great Pyramid of Giza was built. There is evidence of a severe drought lasting about a hundred years that may have caused the decline of these civilizations, with new ones appearing in the aftermath. Babylonians came to dominate Mesopotamia while others, such as

5198-511: The Church would provide centralized authority and education. In the Middle East, Islam became the prominent religion and expanded into North Africa. It led to an Islamic Golden Age , inspiring achievements in architecture , the revival of old advances in science and technology, and the formation of a distinct way of life. The Christian and Islamic worlds would eventually clash, with

5311-560: The Declaration on Great Apes , should be given basic human rights . In 1999, New Zealand was the first country to ban any great ape experimentation, and now 29 countries have currently instituted a research ban to protect great apes from any kind of scientific testing. On 25 June 2008, the Spanish parliament supported a new law that would make "keeping apes for circuses, television commercials or filming" illegal. On 8 September 2010,

5424-774: The European Union banned the testing of great apes . The following table lists the estimated number of great ape individuals living outside zoos. Below is a cladogram with extinct species. It is indicated approximately how many million years ago (Mya) the clades diverged into newer clades. Kenyapithecus (†13 Mya) Sivapithecus (†9) Crown Ponginae Ankarapithecus (†9) Giganthopithecus (†0.1) Khoratpithecus (†7) Pierolapithecus (†11) Hispanopithecus (†10) Lufengpithecus (†7) Khoratpithecus (†9) Ardipithecus (incl. Homo ) Homo sapiens Humans ( Homo sapiens , meaning "thinking man" or "wise man") or modern humans are

5537-474: The Homo genus. The name " Homo sapiens " means 'wise man' or 'knowledgeable man'. There is disagreement if certain extinct members of the genus, namely Neanderthals , should be included as a separate species of humans or as a subspecies of H. sapiens . Human is a loanword of Middle English from Old French humain , ultimately from Latin hūmānus , the adjectival form of homō ('man' – in

5650-579: The Kingdom of England , the Kingdom of France and the Holy Roman Empire declaring a series of holy wars to regain control of the Holy Land from Muslims . In the Americas, between 200 and 900 CE Mesoamerica was in its Classic Period , while further north, complex Mississippian societies would arise starting around 800 CE. The Mongol Empire would conquer much of Eurasia in the 13th and 14th centuries. Over this same time period,

5763-801: The Mali Empire in Africa grew to be the largest empire on the continent, stretching from Senegambia to Ivory Coast . Oceania would see the rise of the Tuʻi Tonga Empire which expanded across many islands in the South Pacific. By the late 15th century, the Aztecs and Inca had become the dominant power in Mesoamerica and the Andes , respectively. The early modern period in Europe and

SECTION 50

#1732765538943

5876-515: The Neolithic Revolution , have consumed mostly cereals and other starchy foods, including increasingly highly processed foods , as well as many other domesticated plants (including fruits) and meat . Gestation in great apes lasts 8–9 months, and results in the birth of a single offspring, or, rarely, twins. The young are born helpless, and require care for long periods of time. Compared with most other mammals, great apes have

5989-587: The Old World over the following millennia. It also occurred independently in Mesoamerica (about 6,000 years ago), China, Papua New Guinea , and the Sahel and West Savanna regions of Africa. Access to food surplus led to the formation of permanent human settlements , the domestication of animals and the use of metal tools for the first time in history. Agriculture and sedentary lifestyle led to

6102-652: The Poverty Point culture , Minoans and the Shang dynasty , rose to prominence in new areas. The Late Bronze Age collapse around 1200 BCE resulted in the disappearance of a number of civilizations and the beginning of the Greek Dark Ages . During this period iron started replacing bronze, leading to the Iron Age . In the 5th century BCE, history started being recorded as a discipline , which provided

6215-446: The bonobo ); and Homo , of which only modern humans ( Homo sapiens ) remain. Numerous revisions in classifying the great apes have caused the use of the term hominid to change over time. The original meaning of "hominid" referred only to humans ( Homo ) and their closest extinct relatives. However, by the 1990s humans and other apes were considered to be "hominids". The earlier restrictive meaning has now been largely assumed by

6328-795: The colonization of the Americas and the Columbian Exchange . This expansion led to the Atlantic slave trade and the genocide of Native American peoples . This period also marked the Scientific Revolution , with great advances in mathematics , mechanics , astronomy and physiology . The late modern period (1800–present) saw the Technological and Industrial Revolution bring such discoveries as imaging technology , major innovations in transport and energy development . Influenced by Enlightenment ideals,

6441-518: The Americas and Europe experienced a period of political revolutions known as the Age of Revolution . The Napoleonic Wars raged through Europe in the early 1800s, Spain lost most of its colonies in the New World , while Europeans continued expansion into Africa  – where European control went from 10% to almost 90% in less than 50 years  – and Oceania. In the 19th century,

6554-488: The Frenchmen in the party accurately mapped for the first time many of the meanders of the Omo River delta. This rendition of the Omo River remained in use until the 1930s when Italian colonial cartographers made a new and more accurate rendition of the river and its delta. There are several power stations and dams in the Omo River basin which are named after the Gilgel Gibe River and Gibe River , which are tributaries of

6667-876: The Mediterranean. In West Asia, the Achaemenid Empire 's system of centralized governance became the precursor to many later empires, while the Gupta Empire in India and the Han dynasty in China have been described as golden ages in their respective regions. Following the fall of the Western Roman Empire in 476, Europe entered the Middle Ages . During this period, Christianity and

6780-832: The Near East ( c.  1450 –1800) began with the final defeat of the Byzantine Empire , and the rise of the Ottoman Empire . Meanwhile, Japan entered the Edo period , the Qing dynasty rose in China and the Mughal Empire ruled much of India. Europe underwent the Renaissance , starting in the 15th century, and the Age of Discovery began with the exploring and colonizing of new regions. This included

6893-437: The Omo River. Despite the somewhat confusing naming they are native power stations and dams located on the Omo River. The Gilgel Gibe II Power Station 7°45′23″N 37°33′45″E  /  7.756492664604506°N 37.56255950100352°E  / 7.756492664604506; 37.56255950100352 is a hydroelectric power station on the Omo River with a power output of 420 Megawatt (MW). The power station receives water from

SECTION 60

#1732765538943

7006-612: The Omo and the Gibe rivers to be one and the same river but with different names. Consequently, the whole river basin is sometimes called the Omo-Gibe River Basin . This river basin includes part of the western Oromia Region and the middle of the Southern Nations, Nationalities, and People's Region . Its course is generally to the south, however with a major bend to the west at about 7° N 37° 30' E to about 36° E where it turns south until 5° 30' N where it makes

7119-412: The Omo delta on 12 September 1898, and found that an Ethiopian expedition, led by Ras Wolda Giyorgis , had previously planted Ethiopian flags on the northern shore of Lake Turkana on 7 April, as well as having plundered the locals and reduced them to poverty. Lieutenant Alexander Bulatovich led a second Ethiopian expedition which reached the lake August 21, 1899, and was equally destructive. Despite this,

7232-631: The ancestry of gibbons, which may have originated in a still-unknown South East Asian hominoid population; but fossil proto-orangutans, dated to around 10 million years ago, may be represented by Sivapithecus from India and Griphopithecus from Turkey. Species close to the last common ancestor of gorillas, chimpanzees and humans may be represented by Nakalipithecus fossils found in Kenya and Ouranopithecus fossils found in Greece . Molecular evidence suggests that between 8 and 4 million years ago, first

7345-478: The available food, improving aesthetics , increasing knowledge or enhancing the exchange of resources. Humans are one of the most adaptable species, despite having a low or narrow tolerance for many of the earth's extreme environments. Currently the species is present in all eight biogeographical realms , although their presence in the Antarctic realm is very limited to research stations and annually there

7458-490: The bare ground. All species are omnivorous , although chimpanzees and orangutans primarily eat fruit. When gorillas run short of fruit at certain times of the year or in certain regions, they resort to eating shoots and leaves, often of bamboo , a type of grass. Gorillas have extreme adaptations for chewing and digesting such low-quality forage, but they still prefer fruit when it is available, often going miles out of their way to find especially preferred fruits. Humans, since

7571-561: The best long-distance runners in the animal kingdom, but slower over short distances. Humans' thinner body hair and more productive sweat glands help avoid heat exhaustion while running for long distances. Compared to other apes, the human heart produces greater stroke volume and cardiac output and the aorta is proportionately larger. Like most animals, humans are a diploid and eukaryotic species. Each somatic cell has two sets of 23 chromosomes , each set received from one parent; gametes have only one set of chromosomes, which

7684-424: The chimpanzees and the gorillas to the genus Homo along with humans.) But, those fossil relatives more closely related to humans than the chimpanzees represent the especially close members of the human family, and without necessarily assigning subfamily or tribal categories. Many extinct hominids have been studied to help understand the relationship between modern humans and the other extant hominids. Some of

7797-665: The collapse of most global empires, leading to widespread decolonization. Following the conclusion of the Second World War in 1945, the United States and the USSR emerged as the remaining global superpowers . This led to a Cold War that saw a struggle for global influence, including a nuclear arms race and a space race , ending in the collapse of the Soviet Union. The current Information Age , spurred by

7910-787: The combined eastern and western Roman Empire in the 4th century AD. Bubonic plagues , first recorded in the 6th century AD, reduced the population by 50%, with the Black Death killing 75–200 million people in Eurasia and North Africa alone. Human population is believed to have reached one billion in 1800. It has since then increased exponentially, reaching two billion in 1930 and three billion in 1960, four in 1975, five in 1987 and six billion in 1999. It passed seven billion in 2011 and passed eight billion in November 2022. It took over two million years of human prehistory and history for

8023-478: The continent, gradually replacing or interbreeding with local populations of archaic humans. Humans began exhibiting behavioral modernity about 160,000–70,000 years ago, and possibly earlier. This development was likely selected amidst natural climate change in Middle to Late Pleistocene Africa. The "out of Africa" migration took place in at least two waves, the first around 130,000 to 100,000 years ago,

8136-410: The country, overgrazing and deforestation are blamed for this tragedy. "The rivers in Ethiopia have less capacity to hold as much water as they did years before, because they are being filled up with silt," World Food Programme spokeswoman Paulette Jones said. "It takes less intensity of rainfall ... to make a river in any particular part of the country overflow." The seasonal flooding of the Omo River

8249-423: The desire to understand and influence phenomena having motivated humanity's development of science , technology , philosophy , mythology , religion , and other frameworks of knowledge ; humans also study themselves through such domains as anthropology , social science , history , psychology , and medicine . There are estimated to be more than eight billion living humans . Although some scientists equate

8362-399: The development of culture comparable to that of chimpanzees, and some say the orangutan may also satisfy those criteria for the theory of mind concept. These scientific debates take on political significance for advocates of great ape personhood . The great apes are tailless primates, with the smallest living species being the bonobo at 30 to 40 kilograms (66 to 88 lb) in weight, and

8475-516: The development of the Internet and Artificial Intelligence systems, sees the world becoming increasingly globalized and interconnected. Early human settlements were dependent on proximity to water and – depending on the lifestyle – other natural resources used for subsistence , such as populations of animal prey for hunting and arable land for growing crops and grazing livestock. Modern humans, however, have

8588-418: The dominant males can no longer control them and the females often mate with other subordinate males. In contrast, groups of gorillas stay together regardless of the availability of fruit. When fruit is hard to find, they resort to eating leaves and shoots. This fact is related to gorillas' greater sexual dimorphism relative to that of chimpanzees; that is, the difference in size between male and female gorillas

8701-626: The drier environments outside the African equatorial belt; and there they encountered antelope, hyenas, elephants and other forms becoming adapted to surviving in the East African savannas , particularly the regions of the Sahel and the Serengeti . The wet equatorial belt contracted after about 8 million years ago, and there is very little fossil evidence for the divergence of the hominin lineage from that of gorillas and chimpanzees—which split

8814-654: The early Miocene , about 22 million years ago, there were many species of tree-adapted primitive catarrhines from East Africa; the variety suggests a long history of prior diversification. Fossils from 20 million years ago include fragments attributed to Victoriapithecus , the earliest Old World monkey. Among the genera thought to be in the ape lineage leading up to 13 million years ago are Proconsul , Rangwapithecus , Dendropithecus , Limnopithecus , Nacholapithecus , Equatorius , Nyanzapithecus , Afropithecus , Heliopithecus , and Kenyapithecus , all from East Africa. At sites far distant from East Africa,

8927-640: The early 20th century, there has been continuous human presence in Antarctica through research stations and, since 2000, in space through habitation on the International Space Station . All modern humans are classified into the species Homo sapiens , coined by Carl Linnaeus in his 1735 work Systema Naturae . The generic name " Homo " is a learned 18th-century derivation from Latin homō , which refers to humans of either sex. The word human can refer to all members of

9040-685: The emergence of early civilizations . An urban revolution took place in the 4th millennium BCE with the development of city-states , particularly Sumerian cities located in Mesopotamia . It was in these cities that the earliest known form of writing, cuneiform script , appeared around 3000 BCE. Other major civilizations to develop around this time were Ancient Egypt and the Indus Valley Civilisation . They eventually traded with each other and invented technology such as wheels, plows and sails. Emerging by 3000 BCE,

9153-402: The extinct members of this family include Gigantopithecus , Orrorin , Ardipithecus , Kenyanthropus , and the australopithecines Australopithecus and Paranthropus . The exact criteria for membership in the tribe Hominini under the current understanding of human origins are not clear, but the taxon generally includes those species that share more than 97% of their DNA with

9266-486: The family Hominidae had already speciated from the family Hylobatidae (the gibbons ), perhaps 15 to 20 million years ago. Due to the close genetic relationship between humans and the other great apes, certain animal rights organizations, such as the Great Ape Project , argue that nonhuman great apes are persons and should be given basic human rights . Twenty-nine countries have instituted research bans to protect great apes from any kind of scientific testing. In

9379-511: The genomes of 1,184 individuals from 11 populations and identified 1.6 million single nucleotide polymorphisms . African populations harbor the highest number of private genetic variants. While many of the common variants found in populations outside of Africa are also found on the African continent, there are still large numbers that are private to these regions, especially Oceania and the Americas . By 2010 estimates, humans have approximately 22,000 genes. By comparing mitochondrial DNA , which

9492-595: The global average life expectancy at birth of a girl is estimated to be 74.9 years compared to 70.4 for a boy. There are significant geographical variations in human life expectancy, mostly correlated with economic development – for example, life expectancy at birth in Hong Kong is 87.6 years for girls and 81.8 for boys, while in the Central African Republic , it is 55.0 years for girls and 50.6 for boys. The developed world

9605-512: The gorillas (genus Gorilla ), and then the chimpanzees (genus Pan ) split off from the line leading to humans. Human DNA is approximately 98.4% identical to that of chimpanzees when comparing single nucleotide polymorphisms (see human evolutionary genetics ). The fossil record, however, of gorillas and chimpanzees is limited; both poor preservation—rain forest soils tend to be acidic and dissolve bone—and sampling bias probably contribute most to this problem. Other hominins probably adapted to

9718-443: The human lifestyle. Genes and the environment influence human biological variation in visible characteristics, physiology , disease susceptibility, mental abilities, body size, and life span. Though humans vary in many traits, humans are among the least genetically diverse species. Any two humans are at least 99.5% genetically similar. Humans are sexually dimorphic : generally, males have greater body strength and females have

9831-555: The human population to reach one billion and only 207 years more to grow to 7 billion. The combined biomass of the carbon of all the humans on Earth in 2018 was estimated at 60 million tons, about 10 times larger than that of all non-domesticated mammals. In 2018, 4.2 billion humans (55%) lived in urban areas, up from 751 million in 1950. The most urbanized regions are Northern America (82%), Latin America (81%), Europe (74%) and Oceania (68%), with Africa and Asia having nearly 90% of

9944-517: The human population was reduced to a small number of breeding pairs. The forces of natural selection have continued to operate on human populations, with evidence that certain regions of the genome display directional selection in the past 15,000 years. The human genome was first sequenced in 2001 and by 2020 hundreds of thousands of genomes had been sequenced. In 2012 the International HapMap Project had compared

10057-402: The largest being the eastern gorillas, with males weighing 140 to 180 kilograms (310 to 400 lb). In all great apes, the males are, on average, larger and stronger than the females, although the degree of sexual dimorphism varies greatly among species. Hominid teeth are similar to those of the Old World monkeys and gibbons, although they are especially large in gorillas. The dental formula

10170-567: The late Miocene epoch. During this split, chromosome 2 was formed from the joining of two other chromosomes, leaving humans with only 23 pairs of chromosomes, compared to 24 for the other apes. Following their split with chimpanzees and bonobos, the hominins diversified into many species and at least two distinct genera. All but one of these lineages – representing the genus Homo and its sole extant species Homo sapiens  – are now extinct. The genus Homo evolved from Australopithecus . Though fossils from

10283-486: The later Homo sapiens remains found on the riverbanks. Since then, the excavations have been carried out by a joint French and American team. In addition to early hominid fossils, a diversity of mammal and fish fossils have been found within the Omo Valley. The lower valley of the Omo is currently believed by some to have been a crossroads for thousands of years as various cultures and ethnic groups migrated around

10396-501: The modern human genome , and exhibit a capacity for language or for simple cultures beyond their 'local family' or band. The theory of mind concept—including such faculties as empathy, attribution of mental state, and even empathetic deception—is a controversial criterion; it distinguishes the adult human alone among the hominids. Humans acquire this capacity after about four years of age, whereas it has not been proven (nor has it been disproven) that gorillas or chimpanzees ever develop

10509-501: The most common and widespread species of primate , and the last surviving species of the genus Homo . They are great apes characterized by their hairlessness , bipedalism , and high intelligence . Humans have large brains , enabling more advanced cognitive skills that enable them to thrive and adapt in varied environments, develop highly complex tools , and form complex social structures and civilizations . Humans are highly social , with individual humans tending to belong to

10622-559: The ongoing mass extinction of other forms of life. Within the last century, humans have explored challenging environments such as Antarctica , the deep sea , and outer space . Human habitation within these hostile environments is restrictive and expensive, typically limited in duration, and restricted to scientific , military , or industrial expeditions. Humans have visited the Moon and made their presence known on other celestial bodies through human-made robotic spacecraft . Since

10735-442: The only primates to have short, relatively flush canine teeth . Humans have characteristically crowded teeth, with gaps from lost teeth usually closing up quickly in young individuals. Humans are gradually losing their third molars , with some individuals having them congenitally absent. Humans share with chimpanzees a vestigial tail, appendix , flexible shoulder joints, grasping fingers and opposable thumbs . Humans also have

10848-474: The palm of the hand and on the soles of the feet. It is estimated that the worldwide average height for an adult human male is about 171 cm (5 ft 7 in), while the worldwide average height for adult human females is about 159 cm (5 ft 3 in). Shrinkage of stature may begin in middle age in some individuals but tends to be typical in the extremely aged . Throughout history, human populations have universally become taller, probably as

10961-573: The pastoralists and agro-pastoralists indigenous to the lower Omo basin. Hominid sister: Hylobatidae The Hominidae ( / h ɒ ˈ m ɪ n ɪ d iː / ), whose members are known as the great apes or hominids ( / ˈ h ɒ m ɪ n ɪ d z / ), are a taxonomic family of primates that includes eight extant species in four genera : Pongo (the Bornean , Sumatran and Tapanuli orangutan ); Gorilla (the eastern and western gorilla ); Pan (the chimpanzee and

11074-515: The population density varies from one region to another, and large stretches of surface are almost completely uninhabited, like Antarctica and vast swathes of the ocean. Most humans (61%) live in Asia; the remainder live in the Americas (14%), Africa (14%), Europe (11%), and Oceania (0.5%). Estimates of the population at the time agriculture emerged in around 10,000 BC have ranged between 1 million and 15 million. Around 50–60 million people lived in

11187-543: The presence of other generalized non- cercopithecids , that is, non-monkey primates, of middle Miocene age— Otavipithecus from cave deposits in Namibia, and Pierolapithecus and Dryopithecus from France, Spain and Austria—is further evidence of a wide diversity of ancestral ape forms across Africa and the Mediterranean basin during the relatively warm and equable climatic regimes of the early and middle Miocene. The most recent of these far-flung Miocene apes ( hominoids )

11300-454: The project, adding that more than half of the people that live in the area are dependent on food aid and that the new station is necessary as currently the corporation is only supplying power for 25 per cent of the population. Heavy rains in 2006 caused the Omo to flood its lower course, drowning at least 456 people and stranding over 20,000 people over the space of five days ending 16 August. While seasonal heavy rains are normal for this part of

11413-551: The region. To this day, the people of the Lower Valley of the Omo, including the Mursi , Suri , Nyangatom , Dizi and Me'en , are studied for their diversity . Italian explorer Vittorio Bottego first reached the Omo river on 29 June 1896 during his second African expedition (1895–97), dying during this expedition on 17 March 1897. The Omo river was renamed Omo-Bottego in his honour. Herbert Henry Austin and his men reached

11526-404: The second ( Southern Dispersal ) around 70,000 to 50,000 years ago. H. sapiens proceeded to colonize all the continents and larger islands, arriving in Eurasia 125,000 years ago, Australia around 65,000 years ago, the Americas around 15,000 years ago, and remote islands such as Hawaii , Easter Island , Madagascar , and New Zealand in the years 300 to 1280 CE. Human evolution was not

11639-547: The sense of humanity). The native English term man can refer to the species generally (a synonym for humanity ) as well as to human males. It may also refer to individuals of either sex. Despite the fact that the word animal is colloquially used as an antonym for human , and contrary to a common biological misconception , humans are animals . The word person is often used interchangeably with human , but philosophical debate exists as to whether personhood applies to all humans or all sentient beings , and further if

11752-438: The taxon Hominidae, a number of extant and extinct genera are grouped with the humans, chimpanzees, and gorillas in the subfamily Homininae ; others with orangutans in the subfamily Ponginae (see classification graphic below). The most recent common ancestor of all Hominidae lived roughly 14 million years ago, when the ancestors of the orangutans speciated from the ancestral line of the other three genera. Those ancestors of

11865-421: The term hominin , which comprises all members of the human clade after the split from the chimpanzees ( Pan ). The current meaning of "hominid" includes all the great apes including humans. Usage still varies, however, and some scientists and laypersons still use "hominid" in the original restrictive sense; the scholarly literature generally shows the traditional usage until the turn of the 21st century. Within

11978-433: The term "humans" with all members of the genus Homo , in common usage it generally refers to Homo sapiens , the only extant member. All other members of the genus Homo , which are now extinct, are known as archaic humans , and the term "modern human" is used to distinguish Homo sapiens from archaic humans. Anatomically modern humans emerged around 300,000 years ago in Africa, evolving from Homo heidelbergensis or

12091-427: The transition are scarce, the earliest members of Homo share several key traits with Australopithecus . The earliest record of Homo is the 2.8 million-year-old specimen LD 350-1 from Ethiopia , and the earliest named species are Homo habilis and Homo rudolfensis which evolved by 2.3 million years ago. H. erectus (the African variant is sometimes called H. ergaster ) evolved 2 million years ago and

12204-494: The use of Pongidae to be restricted to just one closely related grouping. Thus, many biologists now assign Pongo (as the sub family Ponginae ) to the family Hominidae. The taxonomy shown here follows the monophyletic groupings according to the modern understanding of human and great ape relationships. Humans and close relatives including the tribes Hominini and Gorillini form the subfamily Homininae (see classification graphic below). (A few researchers go so far as to refer

12317-440: The world's 3.4 billion rural population. Problems for humans living in cities include various forms of pollution and crime , especially in inner city and suburban slums . Most aspects of human physiology are closely homologous to corresponding aspects of animal physiology. The dental formula of humans is: 2.1.2.3 2.1.2.3 . Humans have proportionately shorter palates and much smaller teeth than other primates. They are

12430-559: Was originally the name given to the family of humans and their (extinct) close relatives, with the other great apes (that is, the orangutans, gorillas and chimpanzees) all being placed in a separate family, the Pongidae . However, that definition eventually made Pongidae paraphyletic because at least one great ape species (the chimpanzees) proved to be more closely related to humans than to other great apes. Most taxonomists today encourage monophyletic groups—this would require, in this case,

12543-402: Was the first archaic human species to leave Africa and disperse across Eurasia. H. erectus also was the first to evolve a characteristically human body plan . Homo sapiens emerged in Africa around 300,000 years ago from a species commonly designated as either H. heidelbergensis or H. rhodesiensis , the descendants of H. erectus that remained in Africa. H. sapiens migrated out of

12656-525: Was thought that the tools might have been part of a so-called pre-Oldowan industry, even more primitive than what was found in the Olduvai Gorge . Later research has shown that the crude looks of the tools were in fact caused by very poor raw materials, and that the techniques used and the shapes permit their inclusion in the Oldowan . The first archaeological discoveries in the area were in 1901, by

12769-403: Was thought to have occurred around that time. The earliest fossils argued by some to belong to the human lineage are Sahelanthropus tchadensis (7 Ma) and Orrorin tugenensis (6 Ma), followed by Ardipithecus (5.5–4.4 Ma), with species Ar. kadabba and Ar. ramidus . The classification of the great apes has been revised several times in the last few decades; these revisions have led to

#942057