76-432: Evolutionary anthropology , the interdisciplinary study of the evolution of human physiology and human behaviour and of the relation between hominids and non-hominid primates , builds on natural science and on social science . Various fields and disciplines of evolutionary anthropology include: Evolutionary anthropology studies both the biological and the cultural evolution of humans, past and present. Based on
152-519: A scientific approach, it brings together fields such as archaeology, behavioral ecology , psychology , primatology, and genetics . As a dynamic and interdisciplinary field, it draws on many lines of evidence to understand the human experience , past and present. Studies of human biological evolution generally focus on the evolution of the human form. Cultural evolution involves the study of cultural change over time and space and frequently incorporates cultural-transmission models. Cultural evolution
228-491: A common ancestor about 660,000 years ago. However, a sequencing of the Neanderthal genome in 2010 indicated that Neanderthals did indeed interbreed with anatomically modern humans c. 45,000-80,000 years ago, around the time modern humans migrated out from Africa, but before they dispersed throughout Europe, Asia and elsewhere. The genetic sequencing of a 40,000-year-old human skeleton from Romania showed that 11% of its genome
304-526: A functional shift toward grinding and crushing in the cheek teeth as an adaptation towards increasing omnivory and herbivory. The skull of Plesiadapis is relatively broad and flat, with a long snout with rodent-like jaws and teeth and long, gnawing incisors separated by a gap from its molars . Orbits are still directed to the side, unlike the forward-facing eyeballs of modern primates that enable three-dimensional vision. Plesiadapis had mobile limbs that terminated in strongly curved claws, and it sported
380-599: A higher rate of depression. The flow of genes from Neanderthal populations to modern humans was not all one way. Sergi Castellano of the Max Planck Institute for Evolutionary Anthropology reported in 2016 that while Denisovan and Neanderthal genomes are more related to each other than they are to us, Siberian Neanderthal genomes show more similarity to modern human genes than do European Neanderthal populations. This suggests Neanderthal populations interbred with modern humans around 100,000 years ago, probably somewhere in
456-531: A long bushy tail which is preserved in the Menat skeletons. The way of life of Plesiadapis has been much debated in the past. Climbing habits could be expected in a relative of the primates, but tree-dwelling animals are rarely found in such high numbers. Based on this and other evidence, some paleontologists have concluded that these animals were mainly living on the ground, like today's marmots and ground squirrels. However, more recent investigations have confirmed that
532-485: A number of clear anatomical differences between anatomically modern humans (AMH) and Neanderthal specimens, many relating to the superior Neanderthal adaptation to cold environments. Neanderthal surface to volume ratio was even lower than that among modern Inuit populations, indicating superior retention of body heat. Neanderthals also had significantly larger brains, as shown from brain endocasts, casting doubt on their intellectual inferiority to modern humans. However,
608-485: A phylogenetic analysis that includes also the basal primate Archicebus positions Plesiadapis firmly outside of the Primates, as a sister group to both Primates and Dermoptera . Plesiadapis is one of the most completely known early primatomorphs, with a significant amount of the skeleton known. Though, the skeleton is mostly known from P. gidleyi and the relatively late (derived) P. tricuspidens . The skull
684-476: A related lineage. In September 2019, scientists reported the computerized determination, based on 260 CT scans , of a virtual skull shape of the last common human ancestor to modern humans ( H. sapiens ), representative of the earliest modern humans, and suggested that modern humans arose between 260,000 and 350,000 years ago through a merging of populations in East and South Africa. Between 400,000 years ago and
760-469: A study of the life history of Ar. ramidus that the species provides evidence for a suite of anatomical and behavioral adaptations in very early hominins unlike any species of extant great ape. This study demonstrated affinities between the skull morphology of Ar. ramidus and that of infant and juvenile chimpanzees, suggesting the species evolved a juvenalised or paedomorphic craniofacial morphology via heterochronic dissociation of growth trajectories. It
836-592: Is Kamoyapithecus from the uppermost Oligocene at Eragaleit in the northern Great Rift Valley in Kenya, dated to 24 million years ago. Its ancestry is thought to be species related to Aegyptopithecus , Propliopithecus , and Parapithecus from the Faiyum, at around 35 mya. In 2010, Saadanius was described as a close relative of the last common ancestor of the crown catarrhines, and tentatively dated to 29–28 mya, helping to fill an 11-million-year gap in
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#1733093511956912-510: Is a reference to the adapiform primate of the Eocene period , Adapis . Plesiadapis tricuspidens , the type specimen, is named after the three cusps present on its upper incisors. The first discovery of Plesiadapis was made by François Louis Paul Gervaise in 1877, who first discovered Plesiadapis tricuspidens in France. The type specimen is MNHN Crl-16, and is a left mandibular fragment dated to
988-445: Is claimed to have been discovered living at the same time period of A. afarensis . There is debate whether A. deyiremeda is a new species or is A. afarensis . Australopithecus prometheus , otherwise known as Little Foot has recently been dated at 3.67 million years old through a new dating technique, making the genus Australopithecus as old as afarensis . Given the opposable big toe found on Little Foot, it seems that
1064-457: Is consistent with recent studies indicating that the divergence of some human alleles dates to one Ma, although this interpretation has been questioned. Neanderthals and AMH Homo sapiens could have co-existed in Europe for as long as 10,000 years, during which AMH populations exploded, vastly outnumbering Neanderthals, possibly outcompeting them by sheer numbers. In 2008, archaeologists working at
1140-686: Is evidence of a wide diversity of forms across Africa and the Mediterranean basin during the relatively warm and equable climatic regimes of the Early and Middle Miocene. The youngest of the Miocene hominoids, Oreopithecus , is from coal beds in Italy that have been dated to 9 million years ago. Molecular evidence indicates that the lineage of gibbons diverged from the line of great apes some 18–12 mya, and that of orangutans (subfamily Ponginae ) diverged from
1216-486: Is intriguing both for its size and its age, being an example of a recent species of the genus Homo that exhibits derived traits not shared with modern humans. In other words, H. floresiensis shares a common ancestor with modern humans, but split from the modern human lineage and followed a distinct evolutionary path. The main find was a skeleton believed to be a woman of about 30 years of age. Found in 2003, it has been dated to approximately 18,000 years old. The living woman
1292-405: Is limited; both poor preservation – rain forest soils tend to be acidic and dissolve bone – and sampling bias probably contribute to this problem. Other hominins probably adapted to the drier environments outside the equatorial belt; and there they encountered antelope, hyenas, dogs, pigs, elephants, horses, and others. The equatorial belt contracted after about 8 million years ago, and there
1368-437: Is not the same as biological evolution: human culture involves the transmission of cultural information (compare memetics ), and such transmission can behave in ways quite distinct from human biology and genetics . The study of cultural change increasingly takes place through cladistics and genetic models. Human evolution Human evolution is the evolutionary process within the history of primates that led to
1444-400: Is overall reminiscent of a lemur , though it lacks the postorbital bars (a vertical bar bordering the posterior margin of the eye socket). The brain was probably relatively large compared to similarly sized contemporary mammals, namely the arctocyonids . The dental formula is usually 2.1.3.3 1.1.3.3 , with two incisors , one canine , three premolars , and three molars in either half of
1520-693: Is seen most completely in the Upper Eocene and lowermost Oligocene fossil beds of the Faiyum depression southwest of Cairo —gave rise to all extant primate species, including the lemurs of Madagascar , lorises of Southeast Asia, galagos or "bush babies" of Africa, and to the anthropoids , which are the Platyrrhines or New World monkeys, the Catarrhines or Old World monkeys, and the great apes, including humans and other hominids. The earliest known catarrhine
1596-518: Is still some debate among academics whether certain African hominid species of this time, such as A. robustus and A. boisei , constitute members of the same genus; if so, they would be considered to be "robust australopiths" while the others would be considered "gracile australopiths". However, if these species do indeed constitute their own genus, then they may be given their own name, Paranthropus . A new proposed species Australopithecus deyiremeda
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#17330935119561672-687: Is supported in part, because some modern humans who live on Flores , the Indonesian island where the skeleton was found, are pygmies . This, coupled with pathological dwarfism, could have resulted in a significantly diminutive human. The other major attack on H. floresiensis as a separate species is that it was found with tools only associated with H. sapiens . The hypothesis of pathological dwarfism, however, fails to explain additional anatomical features that are unlike those of modern humans (diseased or not) but much like those of ancient members of our genus. Aside from cranial features, these features include
1748-408: Is very little fossil evidence for the split—thought to have occurred around that time—of the hominin lineage from the lineages of gorillas and chimpanzees. 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 . It has been argued in
1824-617: The Gorillini tribe between 8 and 9 mya; Australopithecine (including the extinct biped ancestors of humans) separated from the Pan genus (containing chimpanzees and bonobos ) 4–7 mya. The Homo genus is evidenced by the appearance of H. habilis over 2 mya, while anatomically modern humans emerged in Africa approximately 300,000 years ago. The evolutionary history of primates can be traced back 65 million years. One of
1900-605: The Late Cretaceous period, with their earliest fossils appearing over 55 mya, during the Paleocene . Primates produced successive clades leading to the ape superfamily, which gave rise to the hominid and the gibbon families; these diverged some 15–20 mya. African and Asian hominids (including orangutans ) diverged about 14 mya. Hominins (including the Australopithecine and Panina subtribes) parted from
1976-486: The Late Pliocene or Early Pleistocene , 2.5–2 Ma, when it diverged from the australopithecines with the development of smaller molars and larger brains. One of the first known hominins, it made tools from stone and perhaps animal bones, leading to its name homo habilis (Latin 'handy man') bestowed by discoverer Louis Leakey . Some scientists have proposed moving this species from Homo into Australopithecus due to
2052-462: The Pleistocene played a significant role in human evolution observed via human transitions between subsistence systems. The most significant of these adaptations are bipedalism, increased brain size, lengthened ontogeny (gestation and infancy), and decreased sexual dimorphism . The relationship between these changes is the subject of ongoing debate. Other significant morphological changes included
2128-466: The fossil record , cranial capacity had doubled to 850 cm . (Such an increase in human brain size is equivalent to each generation having 125,000 more neurons than their parents.) It is believed that H. erectus and H. ergaster were the first to use fire and complex tools, and were the first of the hominin line to leave Africa, spreading throughout Africa, Asia, and Europe between 1.3 to 1.8 million years ago . According to
2204-523: The gorillas and chimpanzees, diverged from the hominin line over a period covering the same time, so either Sahelanthropus or Orrorin may be our last shared ancestor. Ardipithecus , a full biped, arose approximately 5.6 million years ago. Plesiadapis Plesiadapis is one of the oldest known primate -like mammal genera which existed about 58–55 million years ago in North America and Europe. Plesiadapis means "near-Adapis", which
2280-517: The Australopithecine and Panina subtribes) parted from the Gorillini tribe (gorillas) between 8 and 9 mya; Australopithecine (including the extinct biped ancestors of humans) separated from the Pan genus (containing chimpanzees and bonobos) 4–7 mya. The Homo genus is evidenced by the appearance of H. habilis over 2 mya, while anatomically modern humans emerged in Africa approximately 300,000 years ago. Species close to
2356-826: The Early Pleistocene, 1.5–1 Ma, some populations of Homo habilis are thought to have evolved larger brains and to have made more elaborate stone tools; these differences and others are sufficient for anthropologists to classify them as a new species, Homo erectus —in Africa. The evolution of locking knees and the movement of the foramen magnum are thought to be likely drivers of the larger population changes. This species also may have used fire to cook meat. Richard Wrangham notes that Homo seems to have been ground dwelling, with reduced intestinal length, smaller dentition, and "brains [swollen] to their current, horrendously fuel-inefficient size", and hypothesizes that control of fire and cooking, which released increased nutritional value,
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2432-514: The Indonesian island of Java. He originally named the material Anthropopithecus erectus (1892–1893, considered at this point as a chimpanzee-like fossil primate) and Pithecanthropus erectus (1893–1894, changing his mind as of based on its morphology, which he considered to be intermediate between that of humans and apes). Years later, in the 20th century, the German physician and paleoanthropologist Franz Weidenreich (1873–1948) compared in detail
2508-450: The Near East. Studies of a Neanderthal child at Gibraltar show from brain development and tooth eruption that Neanderthal children may have matured more rapidly than Homo sapiens . H. floresiensis , which lived from approximately 190,000 to 50,000 years before present (BP), has been nicknamed the hobbit for its small size, possibly a result of insular dwarfism . H. floresiensis
2584-651: The Toba catastrophe; however, nearby H. floresiensis survived it. The early phase of H. erectus , from 1.8 to 1.25 Ma, is considered by some to be a separate species, H. ergaster , or as H. erectus ergaster , a subspecies of H. erectus . Many paleoanthropologists now use the term Homo ergaster for the non-Asian forms of this group, and reserve H. erectus only for those fossils that are found in Asia and meet certain skeletal and dental requirements which differ slightly from H. ergaster . In Africa in
2660-468: The absence of aggressive canine morphology in Ar. ramidus and the implications this has for the evolution of hominin social psychology, they wrote: Of course Ar. ramidus differs significantly from bonobos, bonobos having retained a functional canine honing complex. However, the fact that Ar. ramidus shares with bonobos reduced sexual dimorphism, and a more paedomorphic form relative to chimpanzees, suggests that
2736-439: The ancestral hominin line. There is yet no consensus as to which of these groups should be considered a separate species and which should be subspecies; this may be due to the dearth of fossils or to the slight differences used to classify species in the genus Homo . The Sahara pump theory (describing an occasionally passable "wet" Sahara desert) provides one possible explanation of the intermittent migration and speciation in
2812-405: The ancient forest and woodland ecosystems of late Miocene and early Pliocene Africa. Consequently, they argue that humans may not represent evolution from a chimpanzee-like ancestor as has traditionally been supposed. This suggests many modern human adaptations represent phylogenetically deep traits and that the behavior and morphology of chimpanzees may have evolved subsequent to the split with
2888-565: The characters of Dubois' Java Man , then named Pithecanthropus erectus , with the characters of the Peking Man , then named Sinanthropus pekinensis . Weidenreich concluded in 1940 that because of their anatomical similarity with modern humans it was necessary to gather all these specimens of Java and China in a single species of the genus Homo , the species H. erectus . Homo erectus lived from about 1.8 Ma to about 70,000 years ago – which would indicate that they were probably wiped out by
2964-401: The common ancestor they share with humans. The genus Australopithecus evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct 2 million years ago. During this time period various forms of australopiths existed, including Australopithecus anamensis , A. afarensis , A. sediba , and A. africanus . There
3040-408: The developmental and social adaptations evident in bonobos may be of assistance in future reconstructions of early hominin social and sexual psychology. In fact the trend towards increased maternal care, female mate selection and self-domestication may have been stronger and more refined in Ar. ramidus than what we see in bonobos. The authors argue that many of the basic human adaptations evolved in
3116-402: The distribution of stone tools), and faster spread of social and technological innovations. All these may have all contributed to modern Homo sapiens replacing Neanderthal populations by 28,000 BP. Earlier evidence from sequencing mitochondrial DNA suggested that no significant gene flow occurred between H. neanderthalensis and H. sapiens , and that the two were separate species that shared
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3192-472: The divergence point of the mtDNA was unexpectedly deep in time, the full genomic sequence suggested the Denisovans belonged to the same lineage as Neanderthals, with the two diverging shortly after their line split from the lineage that gave rise to modern humans. Modern humans are known to have overlapped with Neanderthals in Europe and the Near East for possibly more than 40,000 years, and the discovery raises
3268-467: The earlier dispersed H. erectus . This migration and origin theory is usually referred to as the "recent single-origin hypothesis" or "out of Africa" theory. H. sapiens interbred with archaic humans both in Africa and in Eurasia, in Eurasia notably with Neanderthals and Denisovans. The Toba catastrophe theory , which postulates a population bottleneck for H. sapiens about 70,000 years ago,
3344-545: The early Eocene epoch. This genus probably arose in North America and colonized Europe on a landbridge via Greenland . Thanks to the abundance of the genus and to its rapid evolution, species of Plesiadapis play an important role in the zonation of Late Paleocene continental sediments and in the correlation of faunas on both sides of the Atlantic. Two remarkable skeletons of Plesiadapis , one of them nearly complete, have been found in lake deposits at Menat, France. Although
3420-458: The emergence of Homo sapiens as a distinct species of the hominid family that includes all the great apes . This process involved the gradual development of traits such as human bipedalism , dexterity , and complex language , as well as interbreeding with other hominins (a tribe of the African hominid subfamily), indicating that human evolution was not linear but weblike. The study of
3496-484: The evolution of a power and precision grip , a change first occurring in H. erectus . Bipedalism , (walking on two legs), is the basic adaptation of the hominid and is considered the main cause behind a suite of skeletal changes shared by all bipedal hominids. The earliest hominin, of presumably primitive bipedalism, is considered to be either Sahelanthropus or Orrorin , both of which arose some 6 to 7 million years ago. The non-bipedal knuckle-walkers,
3572-542: The forerunner of anatomically modern humans , evolved in the Middle Paleolithic between 400,000 and 250,000 years ago. Recent DNA evidence suggests that several haplotypes of Neanderthal origin are present among all non-African populations, and Neanderthals and other hominins, such as Denisovans, may have contributed up to 6% of their genome to present-day humans, suggestive of a limited interbreeding between these species . According to some anthropologists,
3648-594: The form of bones in the wrist, forearm, shoulder, knees, and feet. Additionally, this hypothesis fails to explain the find of multiple examples of individuals with these same characteristics, indicating they were common to a large population, and not limited to one individual. In 2016, fossil teeth and a partial jaw from hominins assumed to be ancestral to H. floresiensis were discovered at Mata Menge , about 74 km (46 mi) from Liang Bua. They date to about 700,000 years ago and are noted by Australian archaeologist Gerrit van den Bergh for being even smaller than
3724-990: The fossil record. In the Early Miocene , about 22 million years ago, the many kinds of arboreally -adapted (tree-dwelling) primitive catarrhines from East Africa suggest a long history of prior diversification. Fossils at 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. The presence of other generalized non-cercopithecids of Middle Miocene from sites far distant, such as Otavipithecus from cave deposits in Namibia, and Pierolapithecus and Dryopithecus from France, Spain and Austria,
3800-530: The genomes of modern humans outside Africa. HLA haplotypes from Denisovans and Neanderthal represent more than half the HLA alleles of modern Eurasians, indicating strong positive selection for these introgressed alleles. Corinne Simoneti at Vanderbilt University, in Nashville and her team have found from medical records of 28,000 people of European descent that the presence of Neanderthal DNA segments may be associated with
3876-628: The genus Homo . Based on archaeological and paleontological evidence, it has been possible to infer, to some extent, the ancient dietary practices of various Homo species and to study the role of diet in physical and behavioral evolution within Homo . Some anthropologists and archaeologists subscribe to the Toba catastrophe theory , which posits that the supereruption of Lake Toba on Sumatra in Indonesia some 70,000 years ago caused global starvation, killing
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#17330935119563952-820: The higher body mass of Neanderthals may have required larger brain mass for body control. Also, recent research by Pearce, Stringer , and Dunbar has shown important differences in brain architecture. The larger size of the Neanderthal orbital chamber and occipital lobe suggests that they had a better visual acuity than modern humans, useful in the dimmer light of glacial Europe. Neanderthals may have had less brain capacity available for social functions . Inferring social group size from endocranial volume (minus occipital lobe size) suggests that Neanderthal groups may have been limited to 120 individuals, compared to 144 possible relationships for modern humans. Larger social groups could imply that modern humans had less risk of inbreeding within their clan, trade over larger areas (confirmed in
4028-598: The last common ancestor of gorillas, chimpanzees and humans may be represented by Nakalipithecus fossils found in Kenya and Ouranopithecus found in Greece. Molecular evidence suggests that between 8 and 4 million years ago, first the gorillas, and then the chimpanzees (genus Pan ) split off from the line leading to the 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
4104-413: The later fossils. A small number of specimens from the island of Luzon , dated 50,000 to 67,000 years ago, have recently been assigned by their discoverers, based on dental characteristics, to a novel human species, H. luzonensis . H. sapiens (the adjective sapiens is Latin for "wise" or "intelligent") emerged in Africa around 300,000 years ago, likely derived from H. heidelbergensis or
4180-499: The lower canines. The skeletal adaptations are consistent with a largely arboreal lifestyle in the trees. The sacrum of P. gidleyi is similar to that of the eastern gray squirrel , though lacking the strong spines. The humerus is robust and features a strong S-curve. Nearly all of what is known about the anatomy of plesiadapiforms comes from fragmentary jaws and teeth, so most definitions of plesiadapiform genera and species are based on dentition. Plesiadapis' dentition shows
4256-594: The majority of humans and creating a population bottleneck that affected the genetic inheritance of all humans today. The genetic and archaeological evidence for this remains in question however. A 2023 genetic study suggests that a similar human population bottleneck of between 1,000 and 100,000 survivors occurred "around 930,000 and 813,000 years ago ... lasted for about 117,000 years and brought human ancestors close to extinction." Homo habilis lived from about 2.8 to 1.4 Ma. The species evolved in South and East Africa in
4332-488: The morphology of its skeleton being more adapted to living in trees rather than walking on two legs like later hominins. In May 2010, a new species, Homo gautengensis , was discovered in South Africa. These are proposed species names for fossils from about 1.9–1.6 Ma, whose relation to Homo habilis is not yet clear. The first fossils of Homo erectus were discovered by Dutch physician Eugene Dubois in 1891 on
4408-643: The oldest known primate-like mammal species, the Plesiadapis , came from North America; another, Archicebus , came from China . Other similar basal primates were widespread in Eurasia and Africa during the tropical conditions of the Paleocene and Eocene . David R. Begun concluded that early primates flourished in Eurasia and that a lineage leading to the African apes and humans, including to Dryopithecus , migrated south from Europe or Western Asia into Africa. The surviving tropical population of primates—which
4484-426: The origins of humans involves several scientific disciplines, including physical and evolutionary anthropology , paleontology , and genetics ; the field is also known by the terms anthropogeny , anthropogenesis , and anthropogony . (The latter two terms are sometimes used to refer to the related subject of hominization .) Primates diverged from other mammals about 85 million years ago ( mya ), in
4560-486: The other great apes at about 12 million years; there are no fossils that clearly document the ancestry of gibbons, which may have originated in a so-far-unknown Southeast Asian hominoid population, but fossil proto-orangutans may be represented by Sivapithecus from India and Griphopithecus from Turkey, dated to around 10 mya. Hominidae subfamily Homininae (African hominids) diverged from Ponginae (orangutans) about 14 mya. Hominins (including humans and
4636-413: The petrosal bone, (2) ectotympanic expanded laterally and fused medially to the wall of the bulla, (3) promontorium centrally positioned in the bulla, and large hypotympanic sinus widely separating promontorium from the basisphenoid, (4) internal carotid entering the bulla posteriolaterally and enclosed in a bony tube, (5) nannopithex fold on the upper molars, and (6) loss of one pair of incisors. In 2013,
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#17330935119564712-740: The possibility that Neanderthals, Denisovans, and modern humans may have co-existed and interbred. The existence of this distant branch creates a much more complex picture of humankind during the Late Pleistocene than previously thought. Evidence has also been found that as much as 6% of the DNA of some modern Melanesians derive from Denisovans, indicating limited interbreeding in Southeast Asia. Alleles thought to have originated in Neanderthals and Denisovans have been identified at several genetic loci in
4788-680: The presence of a suboptic foramen, an ossified external auditory meatus, the absence of a promontory artery, the absence of a stapedial artery, and a strong mastoid tubercle. Although the placement of the Plesiadapis lineage is still up for debate, the consensus in the 1970s was that they were closest to early tarsier -like primates. Plesiadapiformes have also been proposed as a nonprimate sister group to Eocene-Recent primates. A study done in 1987 linked Plesiadapiformes with adapids and omomyids through nine shared-derived features, six of which are cranial or dental: (1) auditory bulla inflated and formed by
4864-409: The preservation of the hard parts is poor, these skeletons still show remains of skin and hair as a carbonaceous film—something unique among Paleocene mammals. Details of the bones are better preserved in fossils from Cernay, also in France, where Plesiadapis is one of the most common mammals. The following are possible shared derived features of Plesiadapiformes: maxillary-frontal contact in orbit,
4940-477: The recent African origin theory, modern humans evolved in Africa possibly from H. heidelbergensis , H. rhodesiensis or H. antecessor and migrated out of the continent some 50,000 to 100,000 years ago, gradually replacing local populations of H. erectus , Denisova hominins , H. floresiensis , H. luzonensis and H. neanderthalensis , whose ancestors had left Africa in earlier migrations. Archaic Homo sapiens ,
5016-575: The second interglacial period in the Middle Pleistocene , around 250,000 years ago, the trend in intra-cranial volume expansion and the elaboration of stone tool technologies developed, providing evidence for a transition from H. erectus to H. sapiens . The direct evidence suggests there was a migration of H. erectus out of Africa , then a further speciation of H. sapiens from H. erectus in Africa. A subsequent migration (both within and out of Africa) eventually replaced
5092-552: The site of Denisova Cave in the Altai Mountains of Siberia uncovered a small bone fragment from the fifth finger of a juvenile member of another human species, the Denisovans. Artifacts, including a bracelet, excavated in the cave at the same level were carbon dated to around 40,000 BP. As DNA had survived in the fossil fragment due to the cool climate of the Denisova Cave, both mtDNA and nuclear DNA were sequenced. While
5168-404: The specimen was a good climber. It is thought given the night predators of the region that he built a nesting platform at night in the trees in a similar fashion to chimpanzees and gorillas. The earliest documented representative of the genus Homo is Homo habilis , which evolved around 2.8 million years ago , and is arguably the earliest species for which there is positive evidence of
5244-652: The transition to behavioral modernity with the development of symbolic culture, language, and specialized lithic technology happened around 50,000 years ago (beginning of the Upper Paleolithic ), although others point to evidence of a gradual change over a longer time span during the Middle Paleolithic. Homo sapiens is the only extant species of its genus, Homo . While some (extinct) Homo species might have been ancestors of Homo sapiens , many, perhaps most, were likely "cousins", having speciated away from
5320-440: The upper jaw; and one incisor, one canine, three premolars, and one molar in either half of the lower jaw. The incisors are quite long. Already, Plesiadapis had lost the first premolar from the mammalian common ancestor, but later primatomorphs would lose the second premolar as well. P. dubius consistently lacks the lower second premolar, and about half of P. rex specimens lack it too. P. gidleyi and European Plesiadapis lack
5396-402: The use of stone tools. The brains of these early hominins were about the same size as that of a chimpanzee, although it has been suggested that this was the time in which the human SRGAP2 gene doubled, producing a more rapid wiring of the frontal cortex. During the next million years a process of rapid encephalization occurred, and with the arrival of Homo erectus and Homo ergaster in
5472-529: Was Neanderthal, implying the individual had a Neanderthal ancestor 4–6 generations previously, in addition to a contribution from earlier interbreeding in the Middle East. Though this interbred Romanian population seems not to have been ancestral to modern humans, the finding indicates that interbreeding happened repeatedly. All modern non-African humans have about 1% to 4% (or 1.5% to 2.6% by more recent data) of their DNA derived from Neanderthals. This finding
5548-479: Was also argued that the species provides support for the notion that very early hominins, akin to bonobos ( Pan paniscus ) the less aggressive species of the genus Pan , may have evolved via the process of self-domestication . Consequently, arguing against the so-called "chimpanzee referential model" the authors suggest it is no longer tenable to use chimpanzee ( Pan troglodytes ) social and mating behaviors in models of early hominin social evolution. When commenting on
5624-549: Was controversial from its first proposal in the 1990s and by the 2010s had very little support. Distinctive human genetic variability has arisen as the result of the founder effect , by archaic admixture and by recent evolutionary pressures . Since Homo sapiens separated from its last common ancestor shared with chimpanzees , human evolution is characterized by a number of morphological , developmental , physiological , behavioral , and environmental changes. Environmental (cultural) evolution discovered much later during
5700-411: Was estimated to be one meter in height, with a brain volume of just 380 cm (considered small for a chimpanzee and less than a third of the H. sapiens average of 1400 cm ). However, there is an ongoing debate over whether H. floresiensis is indeed a separate species. Some scientists hold that H. floresiensis was a modern H. sapiens with pathological dwarfism. This hypothesis
5776-531: Was the key adaptation that separated Homo from tree-sleeping Australopithecines. These are proposed as species intermediate between H. erectus and H. heidelbergensis . H. heidelbergensis ("Heidelberg Man") lived from about 800,000 to about 300,000 years ago. Also proposed as Homo sapiens heidelbergensis or Homo sapiens paleohungaricus . Homo neanderthalensis , alternatively designated as Homo sapiens neanderthalensis , lived in Europe and Asia from 400,000 to about 28,000 years ago. There are
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