108-580: Proteopithecidae is an extinct family of primates which lived in the Priabonian (late Eocene ) and probably early Oligocene periods. Fossils that have been found are in the Jebel Qatrani Formation in Egypt. Currently two genera are recognised, each with a single species, those being Proteopithecus sylviae and Serapia eocaena . Proteopithecus sylviae is unusual in having
216-415: 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
324-668: 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
432-505: A characteristic type of keratin fingernail on the end of each finger and toe. The bottom sides of the hands and feet have sensitive pads on the fingertips . Most have opposable thumbs , a characteristic primate feature most developed in humans , though not limited to this order ( opossums and koalas , for example, also have them). Thumbs allow some species to use tools . In primates, the combination of opposing thumbs, short fingernails (rather than claws) and long, inward-closing fingers
540-443: 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
648-564: A considerable amount of running and pronograde (four limbed) leaping. Seiffert et al. (2010) note that Simons, the discoverer of Serapia originally placed it within the Parapithecidae , but in 2001 transferred Serapia to the Proteopithecidae, a view supported by Gunnell and Miller (2001), Beard (2002), and Seiffert et al. (2004 & 2005a). Kay and Williams (2013, edited by Feagle and Kay) continue to place Serapia in
756-419: 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
864-525: A founding lemur population of a few individuals is thought to have reached Madagascar from Africa via a single rafting event between 50 and 80 mya. Other colonization options have been suggested, such as multiple colonizations from Africa and India, but none are supported by the genetic and molecular evidence. Until recently, the aye-aye has been difficult to place within Strepsirrhini. Theories had been proposed that its family, Daubentoniidae,
972-544: A four-one family distribution instead of five-two as presented here. During the Eocene , most of the northern continents were dominated by two groups, the adapiforms and the omomyids . The former are considered members of Strepsirrhini, but did not have a toothcomb like modern lemurs; recent analysis has demonstrated that Darwinius masillae fits into this grouping. The latter was closely related to tarsiers, monkeys, and apes. How these two groups relate to extant primates
1080-463: 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
1188-612: 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
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#17327981534011296-475: 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
1404-411: A large degree of sexual dimorphism of the canine teeth, which is unknown in extant primates of a similar (relatively small) size. It was arboreal , probably diurnal , probably with a diet of fruit and insects. It weighed around 250 grams. It was the first Eocene anthropoid for which postcranial remains were found. The hindlimbs are similar to those of platyrrhines and indicates an animal that would do
1512-581: 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
1620-504: 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
1728-485: A noun use of Latin primat- , from primus ('prime, first rank'). The name was given by Carl Linnaeus because he thought this the "highest" order of animals. The relationships among the different groups of primates were not clearly understood until relatively recently, so the commonly used terms are somewhat confused. For example, ape has been used either as an alternative for monkey or for any tailless, relatively human-like primate. Sir Wilfrid Le Gros Clark
1836-451: 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
1944-639: 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
2052-515: 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
2160-451: 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
2268-406: 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
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#17327981534012376-511: 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
2484-438: Is a relict of the ancestral practice of gripping branches, and has, in part, allowed some species to develop brachiation (swinging by the arms from tree limb to tree limb) as a significant means of locomotion. Prosimians have clawlike nails on the second toe of each foot, called toilet-claws , which they use for grooming. Human Humans ( Homo sapiens , meaning "thinking man" or "wise man") or modern humans are
2592-485: 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
2700-424: 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
2808-400: Is an order of mammals , which is further divided into the strepsirrhines , which include lemurs , galagos , and lorisids ; and the haplorhines , which include tarsiers and simians ( monkeys and apes ). Primates arose 85–55 million years ago first from small terrestrial mammals, which adapted for life in tropical forests : many primate characteristics represent adaptations to
2916-402: 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
3024-456: 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
3132-581: Is composed of two sister clades. Prosimian tarsiers in the family Tarsiidae (monotypic in its own infraorder Tarsiiformes), represent the most basal division, originating about 58 mya. The earliest known haplorhine skeleton, that of 55 MA old tarsier-like Archicebus , was found in central China, supporting an already suspected Asian origin for the group. The infraorder Simiiformes (simian primates, consisting of monkeys and apes) emerged about 40 mya, possibly also in Asia; if so, they dispersed across
3240-421: 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
3348-479: 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
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3456-443: 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
3564-408: 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
3672-521: 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
3780-445: 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
3888-654: 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 ,
3996-470: Is unclear. Omomyids perished about 30 mya, while adapiforms survived until about 10 mya. According to genetic studies, the lemurs of Madagascar diverged from the lorisoids approximately 75 mya. These studies, as well as chromosomal and molecular evidence, also show that lemurs are more closely related to each other than to other strepsirrhine primates. However, Madagascar split from Africa 160 mya and from India 90 mya. To account for these facts,
4104-946: Is used. New primate species continue to be discovered: over 25 species were described in the 2000s, 36 in the 2010s, and six in the 2020s . Primates have large brains (relative to body size) compared to other mammals, as well as an increased reliance on visual acuity at the expense of the sense of smell , which is the dominant sensory system in most mammals. These features are more developed in monkeys and apes, and noticeably less so in lorises and lemurs. Some primates, including gorillas , humans and baboons , are primarily ground-dwelling rather than arboreal, but all species have adaptations for climbing trees. Arboreal locomotion techniques used include leaping from tree to tree and swinging between branches of trees ( brachiation ); terrestrial locomotion techniques include walking on two hindlimbs ( bipedalism ) and modified walking on four limbs ( quadripedalism ) via knuckle-walking . Primates are among
4212-548: 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
4320-580: 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
4428-511: 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
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4536-548: The Eocene by island hopping , facilitated by Atlantic Ocean ridges and a lowered sea level. Alternatively, a single rafting event may explain this transoceanic colonization. Due to continental drift , the Atlantic Ocean was not nearly as wide at the time as it is today. Research suggests that a small 1 kg (2.2 lb) primate could have survived 13 days on a raft of vegetation. Given estimated current and wind speeds, this would have provided enough time to make
4644-474: 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
4752-579: 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,
4860-854: 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
4968-587: 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
5076-652: 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
5184-530: The Tethys Sea from Asia to Africa soon afterwards. There are two simian clades, both parvorders : Catarrhini , which developed in Africa, consisting of Old World monkeys , humans and the other apes, and Platyrrhini, which developed in South America, consisting of New World monkeys . A third clade, which included the eosimiids , developed in Asia, but became extinct millions of years ago. As in
5292-795: 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,
5400-509: The gibbons and orangutan ... the gorilla and chimpanzee ... and humans "; thereby Benton was using apes to mean hominoids. In that case, the group heretofore called apes must now be identified as the non-human apes. As of 2021 , there is no consensus as to whether to accept traditional (that is, common), but paraphyletic, names or to use monophyletic names only; or to use 'new' common names or adaptations of old ones. Both competing approaches can be found in biological sources, often in
5508-518: 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,
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#17327981534015616-876: 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
5724-832: 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
5832-814: The author, Colin Groves , increased that number to 376 for his contribution to the third edition of Mammal Species of the World (MSW3). However, publications since the taxonomy in MSW3 was compiled in 2003 have pushed the number to 522 species, or 708 including subspecies. Primate hybrids usually arise in captivity, but there have also been examples in the wild. Hybridization occurs where two species' range overlap to form hybrid zones ; hybrids may be created by humans when animals are placed in zoos or due to environmental pressures such as predation. Intergeneric hybridizations, hybrids of different genera, have also been found in
5940-478: 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
6048-561: 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
6156-428: The case of lemurs, the origin of New World monkeys is unclear. Molecular studies of concatenated nuclear sequences have yielded a widely varying estimated date of divergence between platyrrhines and catarrhines, ranging from 33 to 70 mya, while studies based on mitochondrial sequences produce a narrower range of 35 to 43 mya. The anthropoid primates possibly traversed the Atlantic Ocean from Africa to South America during
6264-543: The challenging environment among tree tops , including large brain sizes , binocular vision , color vision , vocalizations , shoulder girdles allowing a large degree of movement in the upper limbs , and opposable thumbs (in most but not all) that enable better grasping and dexterity . Primates range in size from Madame Berthe's mouse lemur , which weighs 30 g (1 oz), to the eastern gorilla , weighing over 200 kg (440 lb). There are 376–524 species of living primates, depending on which classification
6372-419: The clade Euarchontoglires , which is nested within the clade Eutheria of Class Mammalia . Recent molecular genetic research on primates, colugos , and treeshrews has shown that the two species of colugos are more closely related to primates than to treeshrews, even though treeshrews were at one time considered primates. These three orders make up the clade Euarchonta . The combination of this clade with
6480-642: The clade Glires (composed of Rodentia and Lagomorpha ) forms the clade Euarchontoglires. Variously, both Euarchonta and Euarchontoglires are ranked as superorders. Some scientists consider Dermoptera to be a suborder of Primates and use the suborder Euprimates for the "true" primates. The primate lineage is thought to go back at least near the Cretaceous–Paleogene boundary or around 63–74 ( mya ). The earliest possible primate/proto-primate may be Purgatorius , which dates back to Early Paleocene of North America ~66mya. The oldest known primates from
6588-665: 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
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#17327981534016696-787: 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
6804-478: 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,
6912-423: 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
7020-516: 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
7128-640: 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
7236-405: The elaboration of the brain, in particular the neocortex (a part of the cerebral cortex ), which is involved with sensory perception , generation of motor commands , spatial reasoning, conscious thought and, in humans, language . While other mammals rely heavily on their sense of smell , the arboreal life of primates has led to a tactile , visually dominant sensory system, a reduction in
7344-685: 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,
7452-419: The eye sockets reinforces weaker bones in the face, which are put under strain during chewing. Strepsirrhines have a postorbital bar , a bone around the eye socket, to protect their eyes; in contrast, the higher primates, haplorhines , have evolved fully enclosed sockets. Primates show an evolutionary trend towards a reduced snout . Technically, Old World monkeys are distinguished from New World monkeys by
7560-577: The first time. The primate skull has a large, domed cranium , which is particularly prominent in anthropoids . The cranium protects the large brain, a distinguishing characteristic of this group. The endocranial volume (the volume within the skull) is three times greater in humans than in the greatest nonhuman primate, reflecting a larger brain size. The mean endocranial volume is 1,201 cubic centimeters in humans, 469 cm in gorillas , 400 cm in chimpanzees and 397 cm in orangutans . The primary evolutionary trend of primates has been
7668-569: The fossil record date to the Late Paleocene of Africa, c.57 mya ( Altiatlasius ) or the Paleocene-Eocene transition in the northern continents, c. 55 mya ( Cantius , Donrussellia , Altanius , Plesiadapis and Teilhardina ). Other studies, including molecular clock studies, have estimated the origin of the primate branch to have been in the mid-Cretaceous period, around 85 mya. By modern cladistic reckoning,
7776-566: 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
7884-595: 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
7992-443: 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
8100-555: 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
8208-517: 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
8316-567: 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
8424-568: The living Strepsirrhini divides them into two infraorders, Lemuriformes and Lorisiformes. Order Primates was established by Carl Linnaeus in 1758, in the tenth edition of his book Systema Naturae , for the genera Homo (humans), Simia (other apes and monkeys), Lemur (prosimians) and Vespertilio (bats). In the first edition of the same book (1735), he had used the name Anthropomorpha for Homo , Simia and Bradypus (sloths). In 1839, Henri Marie Ducrotay de Blainville , following Linnaeus and aping his nomenclature, established
8532-737: The living primates: groups that use common (traditional) names are shown on the right. Dermoptera [REDACTED] lemurs (superfamily Lemuroidea) [REDACTED] lorises and allies (superfamily Lorisoidea) [REDACTED] tarsiers (superfamily Tarsioidea) [REDACTED] New World monkeys (parvorder Platyrrhini) [REDACTED] Old World monkeys (superfamily Cercopithecoidea) [REDACTED] gibbons (family Hylobatidae) [REDACTED] orangutans (subfamily Ponginae) [REDACTED] gorillas (tribe Gorillini) [REDACTED] humans (g. Homo ) [REDACTED] chimpanzees, bonobos (g. Pan ) [REDACTED] All groups with scientific names are clades , or monophyletic groups, and
8640-563: The most cognitively advanced animals, with humans (genus Homo ) capable of creating complex languages and sophisticated civilizations , and non-human primates are recorded to use tools . They may communicate using facial and hand gestures, smells and vocalizations. Close interactions between humans and non-human primates (NHPs) can create opportunities for the transmission of zoonotic diseases , especially virus diseases including herpes , measles , ebola , rabies and hepatitis . Thousands of non-human primates are used in research around
8748-405: The most social of all animals, forming pairs or family groups, uni-male harems, and multi-male/multi-female groups. Non-human primates have at least four types of social systems , many defined by the amount of movement by adolescent females between groups. Primates have slower rates of development than other similarly sized mammals, reach maturity later, and have longer lifespans. Primates are also
8856-501: 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
8964-475: The number of cusps on their molars : monkeys have four, apes have five - although humans may have four or five. The main hominid molar cusp ( hypocone ) evolved in early primate history, while the cusp of the corresponding primitive lower molar (paraconid) was lost. Prosimians are distinguished by their immobilized upper lips, the moist tip of their noses and forward-facing lower front teeth. Primates generally have five digits on each limb ( pentadactyly ), with
9072-467: The olfactory region of the brain and increasingly complex social behavior. The visual acuity of humans and other hominids is exceptional; they have the most acute vision known among all vertebrates, with the exception of certain species of predatory birds . Primates have forward-facing eyes on the front of the skull; binocular vision allows accurate distance perception, useful for the brachiating ancestors of all great apes. A bony ridge above
9180-559: 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
9288-442: 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
9396-491: The order Primates is monophyletic . The suborder Strepsirrhini , the " wet-nosed " primates, is generally thought to have split off from the primitive primate line about 63 mya, although earlier dates are also supported. The seven strepsirrhine families are the five related lemur families and the two remaining families that include the lorisids and the galagos . Older classification schemes wrap Lepilemuridae into Lemuridae and Galagidae into Lorisidae , yielding
9504-413: The orders Secundates (including the suborders Chiroptera , Insectivora and Carnivora ), Tertiates (or Glires ) and Quaternates (including Gravigrada , Pachydermata and Ruminantia ), but these new taxa were not accepted. Before Anderson and Jones introduced the classification of Strepsirrhini and Haplorhini in 1984, (followed by McKenna and Bell's 1997 work Classification of Mammals: Above
9612-474: 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
9720-453: The parapithecidae as part of a proposed sub-family, Qatraniinae, alongside Arsinoea and Qatrania (they note these all share similar dental features to each other, but they are more primitive than other parapithecidae they also note that the similarity may be because of shared lineage rather than being closely related). Primates sister: Dermoptera Plesiadapiformes ( cladistically including crown primates ) Primates
9828-464: 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
9936-430: The primates, several of these groups are paraphyletic , or rather they do not include all the descendants of a common ancestor. In contrast with Clark's methodology, modern classifications typically identify (or name) only those groupings that are monophyletic ; that is, such a named group includes all the descendants of the group's common ancestor. The cladogram below shows one possible classification sequence of
10044-538: The same work, and sometimes by the same author. Thus, Benton defines apes to include humans, then he repeatedly uses ape-like to mean 'like an ape rather than a human'; and when discussing the reaction of others to a new fossil he writes of "claims that Orrorin ... was an ape rather than a human". A list of the families of the living primates is given below, together with one possible classification into ranks between order and family. Other classifications are also used. For example, an alternative classification of
10152-404: 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
10260-547: 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
10368-430: The sequence of scientific classification reflects the evolutionary history of the related lineages. Groups that are traditionally named are shown on the right; they form an "ascending series" (per Clark, see above), and several groups are paraphyletic: Thus, the members of the two sets of groups, and hence names, do not match, which causes problems in relating scientific names to common (usually traditional) names. Consider
10476-406: The species level ), Primates was divided into two superfamilies: Prosimii and Anthropoidea . Prosimii included all of the prosimians : Strepsirrhini plus the tarsiers . Anthropoidea contained all of the simians . Rodentia (rodents) Lagomorpha (rabbits, hares, pikas) Scandentia (treeshrews) Dermoptera (colugos) † Plesiadapiformes crown primates Order Primates is part of
10584-687: The structure of the nose, and from apes by the arrangement of their teeth . In New World monkeys, the nostrils face sideways; in Old World monkeys, they face downwards. Dental pattern in primates vary considerably; although some have lost most of their incisors , all retain at least one lower incisor. In most strepsirrhines, the lower incisors form a toothcomb , which is used in grooming and sometimes foraging. Old World monkeys have eight premolars , compared with 12 in New World monkeys. The Old World species are divided into apes and monkeys depending on
10692-438: The superfamily Hominoidea: In terms of the common names on the right, this group consists of apes and humans and there is no single common name for all the members of the group. One remedy is to create a new common name, in this case hominoids . Another possibility is to expand the use of one of the traditional names. For example, in his 2005 book, the vertebrate palaeontologist Benton wrote, "The apes, Hominoidea, today include
10800-433: 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
10908-427: 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
11016-769: The voyage between the continents. Apes and monkeys spread from Africa into Europe and Asia starting in the Miocene . Soon after, the lorises and tarsiers made the same journey. The first hominin fossils were discovered in northern Africa and date back 5–8 mya. Old World monkeys disappeared from Europe about 1.8 mya. Molecular and fossil studies generally show that modern humans originated in Africa 100,000–200,000 years ago. Although primates are well studied in comparison to other animal groups, several new species have been discovered recently , and genetic tests have revealed previously unrecognised species in known populations. Primate Taxonomy listed about 350 species of primates in 2001;
11124-413: The wild. Although they belong to genera that have been distinct for several million years, interbreeding still occurs between the gelada and the hamadryas baboon . On 24 January 2018, scientists in China reported in the journal Cell the creation of two crab-eating macaque clones , named Zhong Zhong and Hua Hua , using the complex DNA transfer method that produced Dolly the sheep , for
11232-454: The world because of their psychological and physiological similarity to humans. About 60% of primate species are threatened with extinction. Common threats include deforestation , forest fragmentation , monkey drives , and primate hunting for use in medicines, as pets, and for food. Large-scale tropical forest clearing for agriculture most threatens primates. The English name primates is derived from Old French or French primat , from
11340-440: 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
11448-429: Was either a lemuriform primate (meaning its ancestors split from the lemur line more recently than lemurs and lorises split) or a sister group to all the other strepsirrhines. In 2008, the aye-aye family was confirmed to be most closely related to the other Malagasy lemurs, likely having descended from the same ancestral population that colonized the island. Suborder Haplorhini , the simple-nosed or "dry-nosed" primates,
11556-408: Was one of the primatologists who developed the idea of trends in primate evolution and the methodology of arranging the living members of an order into an "ascending series" leading to humans. Commonly used names for groups of primates such as prosimians , monkeys , lesser apes , and great apes reflect this methodology. According to our current understanding of the evolutionary history of
11664-402: 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
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