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The Denisovans or Denisova hominins ) are an
extinct Extinction is the termination of a kind of organism In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biol ...
species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individu ...

species
or
subspecies In biological classification In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interacti ...
of
archaic human A number of varieties of ''Homo ''Homo'' () is the that emerged in the (otherwise extinct) genus ' that encompasses the extant species ' (), plus several extinct species classified as either to or closely related to modern humans (dependin ...
that ranged across Asia during the
Lower Lower may refer to: *Lower (surname)Lower is a surname. Notable people with the surname include: * Arthur R. M. Lower (1889–1988) Canadian historian * Britt Lower (born 1985), American actress * Cyrus B. Lower (1843–1924), American Civil War ...
and
Middle Paleolithic The Middle Paleolithic (or Middle Palaeolithic) is the second subdivision of the Paleolithic The Paleolithic or Palaeolithic or Palæolithic (), also called the Old Stone Age (from Greek palaios - old, lithos - stone), is a period in prehi ...
. Denisovans are known from few remains, and, consequently, most of what is known about them comes from
DNA Deoxyribonucleic acid (; DNA) is a molecule A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon rings. A molecule is an electrically Electricity is the set of physical ...

DNA
evidence. No formal species name has been erected pending more complete fossil material. The first identification of a Denisovan individual occurred in 2010, based on
mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA Deoxyribonucleic acid (; DNA) is a molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five car ...

mitochondrial DNA
(mtDNA) extracted from a
juvenile Juvenile may refer to: *Juvenile status, or minor (law), prior to adulthood *Juvenile (organism) *Juvenile (rapper) (born 1975), American rapper *Juvenile (2000 film), ''Juvenile'' (2000 film), Japanese film *Juvenile (2017 film), ''Juvenile'' (20 ...
female finger bone from the Siberian
Denisova Cave Denisova Cave (russian: Денисова пещера, lit= the cave of Denis, translit= Denísova peshchéra; alt, Аю-Таш, lit= Bear Rock, translit= Ayu Tash) is a cave in the Bashelaksky Range of the Altai mountains The Altai Mountai ...
in the
Altai Mountains The Altai Mountains (), also spelled Altay Mountains, are a mountain range A mountain range is a series of mountains ranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with simil ...

Altai Mountains
.
Nuclear DNA Nuclear DNA (nDNA), or nuclear deoxyribonucleic acid, is the DNA Deoxyribonucleic acid (; DNA) is a molecule A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon rings. A mole ...
indicates close affinities with
Neanderthal Neanderthals (, also Neandertals, ''Homo neanderthalensis'' or ''Homo sapiens neanderthalensis'') are an extinct species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an org ...
s. The cave was also periodically inhabited by Neanderthals, but it is unclear whether Neanderthals and Denisovans ever cohabited in the cave. Additional specimens from Denisova Cave were subsequently identified, as was a single specimen from the
Baishiya Karst Cave
Baishiya Karst Cave
on the
Tibetan Plateau The Tibetan Plateau (, also known as the Qinghai–Tibet Plateau or the Qing–Zang Plateau () or as the Himalayan Plateau in India, is a vast elevated plateau In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and - ...
in China. DNA evidence suggests they had dark skin, eyes, and hair, and had a Neanderthal-like build and facial features. However, they had larger
molars The molars or molar teeth are large, flat teeth A tooth (plural teeth) is a hard, calcified Calcification is the accumulation of calcium salts in a Tissue (biology), body tissue. It normally occurs in the formation of bone, but calcium ...
which are reminiscent of Middle to
Late Pleistocene The Late Pleistocene is an unofficial age in the international geologic timescale The geologic time scale (GTS) is a system of chronological datingChronological dating, or simply dating, is the process of attributing to an object or event ...
archaic humans and
australopithecine Australopithecina or human taxonomy, Hominina is a subtribe in the tribe Hominini. The members of the subtribe are generally ''Australopithecus'' (cladistically including the genus, genera ''Homo'', ''Paranthropus'', and ''Kenyanthropus''), and ...
s. Denisovans apparently interbred with modern humans, with the highest percentages (roughly 5%) occurring in
Melanesians Melanesians are the predominant and Indigenous peoples of Oceania, indigenous inhabitants of Melanesia, in a wide area from the Maluku Islands, East Nusa Tenggara and New Guinea to as far east as the islands of Vanuatu and Fiji. Most speak eithe ...

Melanesians
,
Aboriginal Australians Aboriginal Australians are the various Indigenous peoples Indigenous peoples, also referred to as first peoples, first nations, aboriginal peoples, native peoples (with these terms often capitalized when referred to relating to specific ...
, and Filipino
Negrito The term Negrito () refers to several diverse ethnic groups who inhabit isolated parts of Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia or SEA, is the geographical U ...

Negrito
s. This distribution suggests that there were Denisovan populations across Eurasia, the Philippines, and New Guinea and/or Australia, but this is unconfirmable.
Introgression Introgression, also known as introgressive hybridization, in genetics Genetics is a branch of biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, ch ...
into
modern humans Early modern human (EMH) or anatomically modern human (AMH) are terms used to distinguish ''Homo sapiens Humans (''Homo sapiens'') are the most abundant and widespread of , characterized by and large, complex brains. This has enabled ...
may have occurred as recently as 30,000 years ago in New Guinea, which, if correct, might indicate this population persisted as late as 14,500 years ago. There is also evidence of interbreeding with the Altai Neanderthal population, with about 17% of the Denisovan genome from Denisova Cave deriving from them. A first-generation hybrid nicknamed " Denny" was discovered with a Denisovan father and a Neanderthal mother. Additionally, 4% of the Denisovan genome comes from an unknown archaic human species which diverged from modern humans over one million years ago.


Taxonomy

Denisovans may represent a new species of ''
Homo ''Homo'' () is the genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), cir ...

Homo
'' or archaic subspecies of ''
Homo sapiens Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedality, bipedalism and large, complex brains. This has enabled the development of advanced tools, culture, and language. Humans are highl ...

Homo sapiens
'' (modern humans), but they are known from too few fossils to erect a proper
taxon In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, Physiology, physiological mechani ...
. Proactively proposed species names for Denisovans are ''H. denisova'' or ''H. altaiensis''.


Discovery

Denisova Cave Denisova Cave (russian: Денисова пещера, lit= the cave of Denis, translit= Denísova peshchéra; alt, Аю-Таш, lit= Bear Rock, translit= Ayu Tash) is a cave in the Bashelaksky Range of the Altai mountains The Altai Mountai ...
is in south-central
Siberia Siberia (; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of R ...

Siberia
, Russia, in the
Altai Mountains The Altai Mountains (), also spelled Altay Mountains, are a mountain range A mountain range is a series of mountains ranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with simil ...

Altai Mountains
near the border with Kazakhstan, China and Mongolia. It is named after Denis (Dyonisiy), a Russian
hermit A hermit, or eremite (adjectival form: hermitic or eremitic), is a person who lives in seclusion. Eremitism plays a role in a variety of religions. Description In Christianity, the term was originally applied to a Christian who lives the eremi ...

hermit
who lived there in the 18th century. The cave was first inspected for fossils in the 1970s by Russian
paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene The Holocene ( ) is the current Geologic time scale, geological epoch. ...
Nikolai Ovodov, who was looking for remains of
canid Canidae (; from Latin, ''canis'', "dog") is a biological family Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy; it is classified between order (biology), order and genus. A famil ...
s. In 2008, Michael Shunkov from the
Russian Academy of Sciences The Russian Academy of Sciences (RAS; russian: Росси́йская акаде́мия нау́к (РАН) ''Rossíiskaya akadémiya naúk'') consists of the national academy#REDIRECT National academy A national academy is an organizational bo ...
and other Russian
archaeologists Archaeology or archeology is the study of human activity through the recovery and analysis Analysis is the process of breaking a complex topic or substance into smaller parts in order to gain a better understanding of it. The technique h ...
from the Institute of Archaeology and Ethnography of the
Siberian Branch of the Russian Academy of Sciences The Siberian Branch of the Russian Academy of Sciences (SBRAS) was established by the Decree of the Government of the USSR which was based on the proposal of Mikhail Lavrentyev, Sergei Sobolev and Sergey Khristianovich in 1957 as a regional divis ...
in
Novosibirsk Novosibirsk (, also ; rus, Новосиби́рск, p=nəvəsʲɪˈbʲirsk, a=ru-Новосибирск.ogg) is the largest city and administrative centre of Novosibirsk Oblast and Siberian Federal District in Russia. It has a population of&n ...
Akademgorodok Coordinates: Akademgorodok ( rus, Акаде́мгородо́к, p=ɐkəˌdʲemɡərɐˈdok, "Academic Town" or "Academic City") is a part of the Sovetsky District of the city of Novosibirsk, Russia Russia (russian: link=no, Рос ...
investigated the cave and found the finger bone of a juvenile female
hominin The Hominini form a taxonomic tribe of the subfamily Homininae Homininae (), also called "African hominids" or "African apes", is a subfamily of Hominidae The Hominidae (), whose members are known as great apes or hominids (), are a t ...
originally dated to 50–30,000 years ago. The estimate has changed to 76,200–51,600 years ago. The specimen was originally named X-woman because
matrilineal Matrilineality is the tracing of kinship In anthropology, kinship is the web of social relationships that form an important part of the lives of all humans in all societies, although its exact meanings even within this discipline are often ...
mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA Deoxyribonucleic acid (; DNA) is a molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five car ...

mitochondrial DNA
(mtDNA) extracted from the bone demonstrated it to belong to a novel ancient hominin, genetically distinct both from contemporary modern humans and from
Neanderthal Neanderthals (, also Neandertals, ''Homo neanderthalensis'' or ''Homo sapiens neanderthalensis'') are an extinct species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an org ...
s. In 2019, Greek archaeologist Katerina Douka and colleagues
radiocarbon dated Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material Organic matter, organic material, or natural organic matter refers to the large source of ...
specimens from Denisova Cave, and estimated that Denisova 2 (the oldest specimen) lived 195,000-122,700 years ago. Older Denisovan DNA collected from sediments in the East Chamber dates to 217,000 years ago. Based on artifacts also discovered in the cave, hominin occupation (most likely by Denisovans) began 287±41 or 203±14 . Neanderthals were also present 193±12 ka and 97±11 ka, possibly concurrently with Denisovans.


Specimens

The fossils of five distinct Denisovan individuals from
Denisova Cave Denisova Cave (russian: Денисова пещера, lit= the cave of Denis, translit= Denísova peshchéra; alt, Аю-Таш, lit= Bear Rock, translit= Ayu Tash) is a cave in the Bashelaksky Range of the Altai mountains The Altai Mountai ...
have been identified through their
ancient DNA Ancient DNA (aDNA) is DNA isolated from ancient Biological specimen, specimens. Due to degradation processes (including Crosslinking of DNA, cross-linking, deamination and DNA fragmentation, fragmentation) ancient DNA is more degraded in comparis ...

ancient DNA
(aDNA): Denisova 2, 3, 4, 8, and 11. An mtDNA-based phylogenetic analysis of these individuals suggests that Denisova 2 is the oldest, followed by Denisova 8, while Denisova 3 and Denisova 4 were roughly contemporaneous. During DNA sequencing, a low proportion of the Denisova 2, Denisova 4 and Denisova 8 genomes were found to have survived, but a high proportion of the Denisova 3 genome was intact. The Denisova 3 sample was cut into two, and the initial DNA sequencing of one fragment was later independently confirmed by sequencing the mtDNA from the second. These specimens remained the only known examples of Denisovans until 2019, when a research group led by Fahu Chen, Dongju Zhang and
Jean-Jacques Hublin Jean-Jacques Hublin (born 30 November 1953) is a French paleoanthropologist Paleoanthropology or paleo-anthropology is a branch of paleontology Paleontology, also spelled palaeontology or palæontology (), is the scientific study of life that ...
described discovered in 1980 by a
Buddhist monk A monk (, from el, μοναχός, ''monachos'', "single, solitary" via Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the ...

Buddhist monk
in the on the
Tibetan Plateau The Tibetan Plateau (, also known as the Qinghai–Tibet Plateau or the Qing–Zang Plateau () or as the Himalayan Plateau in India, is a vast elevated plateau In geology Geology (from the Ancient Greek γῆ, ''gē'' ("earth") and - ...
in China. The fossil became part of the collection of , where it remained unstudied until 2010. It was determined by ancient protein analysis to contain
collagen Collagen () is the main structural protein Proteins are large biomolecule , showing alpha helices, represented by ribbons. This poten was the first to have its suckture solved by X-ray crystallography by Max Perutz and Sir John Cowder ...

collagen
that by sequence was found to have close affiliation to that of the Denisovans from Denisova Cave, while uranium decay dating of the
carbonate In chemistry, a carbonate is a salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of Salt (chemistry), salts; salt in its natural form as a crystallinity, crystalline mi ...

carbonate
crust enshrouding the specimen indicated it was more than 160,000 years old. The identity of this population was later confirmed through study of
environmental DNA Environmental DNA or eDNA is DNA Deoxyribonucleic acid (; DNA) is a molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon rings. A ...

environmental DNA
, which found Denisovan mtDNA in sediment layers ranging in date from 100,000 to 60,000 years before present, and perhaps more recent. Some older findings may or may not belong to the Denisovan line, but Asia is not well mapped in regards to
human evolution Human evolution is the evolution Evolution is change in the heritable Heredity, also called inheritance or biological inheritance, is the passing on of Phenotypic trait, traits from parents to their offspring; either through asexual ...

human evolution
. Such findings include the Dali skull, the
Xujiayao Xujiayao, located in the Nihewan Basin in China, is an early Late Pleistocene paleoanthropology, paleoanthropological site famous for its archaic hominin fossils. Location Xujiayao is located on the west bank of the Liyi River, a tributary of the S ...
hominin,
Maba Man Introduction Maba Man () is the pre-modern hominin whose remains were discovered in 1958 in caves near the town called Maba, Guangdong, Maba, near Shaoguan city in the north part of Guangdong province, China. Characteristics Farmers found ...
, the Jinniushan hominin, and the Narmada hominin. The Xiahe mandible shows morphological similarities to some later East Asian fossils such as
Penghu 1 Penghu 1 is a fossil jaw (mandible In anatomy Anatomy (Greek ''anatomē'', 'dissection') is the branch of biology concerned with the study of the structure of organism In biology, an organism (from Ancient Greek, Greek: ὀργαν ...
, but also to Chinese ''H. erectus''. In 2021, Chinese palaeoanthropologist Qiang Ji suggested his newly erected species, '''', may represent the Denisovans based on the similarity between the type specimen's molar and that of the Xiahe mandible.


Evolution

Sequenced In genetics and biochemistry, sequencing means to determine the primary structure (sometimes incorrectly called the primary sequence) of an unbranched biopolymer. Sequencing results in a symbolic linear depiction known as a sequence which succi ...

Sequenced
mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA Deoxyribonucleic acid (; DNA) is a molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five car ...

mitochondrial DNA
(mtDNA), preserved by the cool climate of the cave (average temperature is at freezing point), was extracted from Denisova 3 by a team of scientists led by
Johannes Krause Johannes Krause (born July 17, 1980 in Leinefelde-Worbis, Leinefelde) is a German biochemist with a research focus on historical infectious diseases and human evolution. Since 2010, he has been professor of archaeology and paleogenetics at the Uni ...

Johannes Krause
and Svante Pääbo from the
Max Planck Institute for Evolutionary Anthropology The Max Planck Institute for Evolutionary Anthropology (german: Max-Planck-Institut für evolutionäre Anthropologie, shortened to MPI EVA) is a research institute based in Leipzig, Germany, that was founded in 1997. It is part of the Max-Planc ...

Max Planck Institute for Evolutionary Anthropology
in
Leipzig Leipzig (, ; Upper Saxon: ) is the most populous city in the Germany, German States of Germany, state of Saxony. With a population of 605,407 inhabitants as of 2021 (1.1 million residents in the larger urban zone), it surpasses the Saxon c ...

Leipzig
, Germany. Denisova 3's mtDNA differs from that of modern humans by 385 bases (
nucleotide Nucleotides are organic molecules , CH4; is among the simplest organic compounds. In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen chemical bond, bonds. Due to carbon's ability to Catenation, ...

nucleotide
s) out of approximately 16,500, whereas the difference between modern humans and
Neanderthals Neanderthals (, also Neandertals, ''Homo neanderthalensis'' or ''Homo sapiens neanderthalensis'') are an extinct species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an org ...
is around 202 bases. In comparison, the difference between
chimpanzee The chimpanzee (''Pan troglodytes''), also known simply as chimp, is a species of Hominidae, great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. The chimpanzee and t ...
s and modern humans is approximately 1,462 mtDNA base pairs. This suggested that Denisovan mtDNA diverged from that of modern humans and Neanderthals about 1,313,500–779,300 years ago; whereas modern human and Neanderthal mtDNA diverged 618,000–321,200 years ago. Krause and colleagues then concluded that Denisovans were the descendants of an earlier migration of ''H. erectus'' out of Africa, completely distinct from modern humans and Neanderthals. However, according to the
nuclear DNA Nuclear DNA (nDNA), or nuclear deoxyribonucleic acid, is the DNA Deoxyribonucleic acid (; DNA) is a molecule A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon rings. A mole ...
(nDNA) of Denisova 3—which had an unusual degree of DNA preservation with only low-level contamination—Denisovans and Neanderthals were more closely related to each other than they were to modern humans. Using the percent distance from human–chimpanzee last common ancestor, Denisovans/Neanderthals split from modern humans about 804,000 years ago, and from each other 640,000 years ago. Using a mutation rate of 1x10−9 or 0.5x10−9 per
base pair A base pair (bp) is a fundamental unit of double-stranded nucleic acids Nucleic acids are biopolymer Biopolymers are natural polymers produced by the cells of Organism, living organisms. Biopolymers consist of monomeric units that are Covalent_ ...
(bp) per year, the Neanderthal/Denisovan split occurred around either 236–190,000 or 473–381,000 years ago respectively. Using 1.1x10−8 per generation with a new generation every 29 years, the time is 744,000 years ago. Using 5x10−10
nucleotide Nucleotides are organic molecules , CH4; is among the simplest organic compounds. In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen chemical bond, bonds. Due to carbon's ability to Catenation, ...

nucleotide
site per year, it is 616,000 years ago. Using the latter dates, the split had likely already occurred by the time hominins spread out across Europe. '''' is typically considered to have been the direct ancestor of Denisovans and Neanderthals, and sometimes also modern humans. Due to the strong divergence in dental anatomy, they may have split before characteristic Neanderthal dentition evolved about 300,000 years ago. The more divergent Denisovan mtDNA has been interpreted as evidence of admixture between Denisovans and an unknown archaic human population, possibly a
relict A relict is a surviving remnant of a natural phenomenon. Biology A relict (or relic) is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas. Geology and geomorphology In geology ...
'''' or ''H. erectus''-like population about 53,000 years ago. Alternatively, divergent mtDNA could have also resulted from the persistence of an ancient mtDNA lineage which only went extinct in modern humans and Neanderthals through
genetic drift Genetic drift (allelic drift or the Sewall Wright effect) is the change in the frequency of an existing gene In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical stru ...

genetic drift
. Modern humans contributed mtDNA to the Neanderthal lineage, but not to the Denisovan mitochondrial genomes yet sequenced. The mtDNA sequence from the femur of a 400,000-year-old ''H. heidelbergensis'' from the Sima de los Huesos Cave in Spain was found to be related to those of Neanderthals and Denisovans, but closer to Denisovans, and the authors posited that this mtDNA represents an archaic sequence which was subsequently lost in Neanderthals due to replacement by a modern-human-related sequence.


Demographics

Denisovans are known to have lived in Siberia, and the Xiahe mandible is the earliest recorded human presence on the Tibetan Plateau. Though their remains have been identified in only these two locations, traces of Denisovan DNA in modern humans suggest they ranged across
East Asia East Asia is the eastern region of Asia, which is defined in both Geography, geographical and culture, ethno-cultural terms. The modern State (polity), states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. ...

East Asia
, and potentially western Eurasia. In 2019,
geneticist A geneticist is a biologist who studies genetics, the science of genes, heredity, and genetic variation, variation of organisms. A geneticist can be employed as a scientist or a lecturer. Geneticists may perform general research on genetic proce ...
Guy Jacobs and colleagues identified three distinct populations of Denisovans in: Siberia and East Asia; New Guinea and nearby islands; and
Oceania Oceania (, , ) is a geographic region In geography Geography (from Greek: , ''geographia'', literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of the Eart ...

Oceania
and, to a lesser extent, across Asia. Using coalescent modeling, the Denisova Cave Denisovans split from the second population about 283,000 years ago; and from the third population about 363,000 years ago. This indicates that there was considerable reproductive isolation between Denisovan populations. Based on the high percentages of Denisovan DNA in modern Papuans and Australians, Denisovans may have crossed the
Wallace Line The Wallace Line or Wallace's Line is a faunal boundary line drawn in 1859 by the British naturalist Alfred Russel Wallace Alfred Russel Wallace (8 January 18237 November 1913) was a British natural history, naturalist, explorer, geo ...
into these regions (with little back-migration west), the first human species to do so. By this logic, they may have also entered the Philippines, living alongside '' H. luzonensis'' which, if this is the case, may represent the same or a closely related species. These Denisovans may have needed to cross large bodies of water. Icelanders also have an anomalously high Denisovan heritage, which could have stemmed from a Denisovan population far west of the Altai mountains. Genetic data suggests Neanderthals were frequently making long crossings between Europe and the Altai mountains especially towards the date of their extinction. Using
exponential distribution In probability theory Probability theory is the branch of mathematics Mathematics (from Greek: ) includes the study of such topics as numbers (arithmetic and number theory), formulas and related structures (algebra), shapes and spaces ...
analysis on
haplotype A haplotype (haploid Ploidy () is the number of complete sets of chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. Most eukaryotic chromosomes include packaging proteins called h ...
lengths, Jacobs calculated
introgression Introgression, also known as introgressive hybridization, in genetics Genetics is a branch of biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, ch ...
into modern humans occurred about 29,900 years ago with the second population; and 45,700 years ago in the third population. Such a late date for the second population could indicate survival as late as 14,500 years ago, which would make them the latest surviving archaic human species. New Guineans have introgression from these two latter populations. A third wave appears to have introgressed into East Asia, but there is not enough DNA evidence to pinpoint a solid timeframe. The mtDNA from Denisova 4 bore a high similarity to that of Denisova 3, indicating that they belonged to the same population. The
genetic diversity Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species, it ranges widely from the number of species to differences within species In biology, a species is the basic unit of biological classificati ...
among the Denisovans from Denisova Cave is on the lower range of what is seen in modern humans, and is comparable to that of Neanderthals. However, it is possible that the inhabitants of Denisova Cave were more or less reproductively isolated from other Denisovans, and that, across their entire range, Denisovan genetic diversity may have been much higher. Denisova Cave, over time of inhabitance, continually swung from a fairly warm and moderately humid pine and birch forest to tundra or forest-tundra landscape. Conversely, Baishiya Karst Cave is situated at a high elevation, an area characterized by low temperature, low oxygen, and poor resource availability. Colonization of high-altitude regions, due to such harsh conditions, was previously assumed to have only been accomplished by modern humans. Denisovans seem to have also inhabited the jungles of Southeast Asia.


Anatomy

Little is known of the precise anatomical features of the Denisovans since the only physical remains discovered so far are a finger bone, three teeth,
long bone The long bones are those that are longer than they are wide. They are one of five types of bone A bone is a rigid tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific funct ...

long bone
fragments, a partial jawbone, and a
parietal bone The parietal bones () are two bones in the skull The skull is a bone A bone is a rigid tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesi ...

parietal bone
skull fragment. The finger bone is within the modern human range of variation for women, which is in contrast to the large, robust molars which are more similar to those of Middle to Late Pleistocene archaic humans. The third molar is outside of the range of any ''Homo'' species except '''' and '''', and is more like those of
australopithecine Australopithecina or human taxonomy, Hominina is a subtribe in the tribe Hominini. The members of the subtribe are generally ''Australopithecus'' (cladistically including the genus, genera ''Homo'', ''Paranthropus'', and ''Kenyanthropus''), and ...
s. The second molar is larger than those of modern humans and Neanderthals, and is more similar to those of '''' and ''H. habilis''. Like Neanderthals, the mandible had a gap behind the molars, and the front teeth were flattened; but Denisovans lacked a high mandibular body, and the
mandibular symphysis In human anatomy, the facial skeleton The facial skeleton comprises the ''facial bones'' that may attach to build a portion of the skull The skull is a bone A bone is a Stiffness, rigid tissue (anatomy), tissue that constitutes part of t ...
at the midline of the jaw was more receding. The parietal is reminiscent of that of ''H. erectus''. A facial reconstruction has been generated by comparing
methylation In the chemical sciences, methylation denotes the addition of a methyl group A methyl group is an alkyl derived from methane, containing one carbon atom chemical bond, bonded to three hydrogen atoms — CH3. In chemical formula, fo ...

methylation
at individual genetic loci associated with facial structure. This analysis suggested that Denisovans, much like Neanderthals, had a long, broad, and projecting face; larger nose; sloping forehead; protruding jaw; elongated and flattened skull; and wide chest and hips. However, the Denisovan tooth row was longer than that of Neanderthals and anatomically modern humans. Middle to Late Pleistocene East Asian archaic human skullcaps typically share features with Neanderthals. The skullcaps from Xuchang feature prominent brow ridges like Neanderthals, though the nuchal and angular tori near the base of the skull are either reduced or absent, and the back of the skull is rounded off like in
early modern human Early modern human (EMH) or anatomically modern human (AMH) are terms used to distinguish ''Homo sapiens Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedality, bipedalism and larg ...
s. Xuchang 1 had a large brain volume of approximately 1800 cc, on the high end for Neanderthals and early modern humans, and well beyond the present-day human average. The Denisovan genome from Denisova Cave has variants of genes which, in modern humans, are associated with dark skin, brown hair, and brown eyes. The Denisovan genome also contains a variant region around the
EPAS1 Endothelial PAS domain-containing protein 1 (EPAS1, also known as hypoxia-inducible factor-2alpha (HIF-2alpha)) is a protein Proteins are large biomolecule , showing alpha helices, represented by ribbons. This poten was the first to have i ...
gene that in
Tibetans The Tibetan people (; ) are an East Asian people, East Asian ethnic group indigenous peoples, native to Tibet. Their current population is estimated to be around 6.7 million. In addition to the majority living in Tibet Autonomous Region of Chin ...
assists with adaptation to low oxygen levels at high elevation, and in a region containing the WARS2 and TBX15 loci which affect body-fat distribution in the
Inuit Inuit (; iu, ᐃᓄᐃᑦ 'the people', singular: Inuk, , dual: Inuuk, ) are a group of culturally similar indigenous peoples Indigenous peoples, also referred to as First people, Aboriginal people, Native people, or autochthonous people, ...
. In Papuans, introgressed Neanderthal alleles are highest in frequency in genes expressed in the brain, whereas Denisovan alleles have highest frequency in genes expressed in bones and other tissue.


Art


Denisova Cave

Early
Middle Paleolithic The Middle Paleolithic (or Middle Palaeolithic) is the second subdivision of the Paleolithic The Paleolithic or Palaeolithic or Palæolithic (), also called the Old Stone Age (from Greek palaios - old, lithos - stone), is a period in prehi ...
stone tools from Denisova Cave were characterized by discoidal (disk-like) cores and Kombewa cores, but Levallois cores and were also present. There were
scraper Scrape, scraper or scraping may refer to: Biology and medicine * Abrasion (medical), a type of injury * Scraper (biology), grazer-scraper, a water animal that feeds on stones and other substrates by grazing algae, microorganism and other matter * ...
s, denticulate tools, and notched tools, deposited about 287±41 thousand years ago in the Main Chamber of the cave; and about 269±97 thousand years ago in the South Chamber; up to 170±19 thousand and 187±14 thousand years ago in the Main and East Chambers, respectively. Middle Paleolithic assemblages were dominated by flat, discoidal, and Levallois cores, and there were some isolated sub-prismatic cores. There were predominantly side scrapers (a scraper with only the sides used to scrape), but also notched-denticulate tools, end-scrapers (a scraper with only the ends used to scrape), burins,
chisel A chisel is a tool A tool is an object that can extend an individual's ability to modify features of the surrounding environment. Although many animals use simple tools, only human beings, whose use of stone tool A stone tool is, in t ...

chisel
-like tools, and truncated flakes. These dated to 156±15 thousand years ago in the Main Chamber, 58±6 thousand years ago in the East Chamber, and 136±26–47±8 thousand years ago in the South Chamber. Early
Upper Paleolithic The Upper Paleolithic (or Upper Palaeolithic) also called the is the third and last subdivision of the or Old . Very broadly, it dates to between 50,000 and years ago (the beginning of the ), according to some theories coinciding with the ...
artefacts date to 44±5 thousand years ago in the Main Chamber, 63±6 thousand years ago in the East Chamber, and 47±8 thousand years ago in the South Chamber, though some layers of the East Chamber seem to have been disturbed. There was
blade A blade is the portion of a tool A tool is an object that can extend an individual's ability to modify features of the surrounding environment. Although many animals use tool use by animals, simple tools, only human beings, whose use of st ...
production and Levallois production, but scrapers were again predominant. A well-developed, Upper Paleolithic stone bladelet technology distinct from the previous scrapers began accumulating in the Main Chamber around 36±4 thousand years ago. In the Upper Paleolithic layers, there were also several
bone tool In archaeology Archaeology or archeology is the study of human activity through the recovery and analysis Analysis is the process of breaking a complexity, complex topic or Substance theory, substance into smaller parts in order to gain a ...
s and ornaments: a
marble Marble is a metamorphic rock , a type of metamorphic rock Metamorphic rocks arise from the transformation of existing rock (geology), rock to new types of rock, in a process called metamorphism upright=1.35, Schematic representation of ...

marble
ring, an ivory ring, an ivory pendant, a
red deer The red deer (''Cervus elaphus'') is one of the largest deer Deer or true deer are ed s forming the Cervidae. The two main groups of deer are the , including the , the (wapiti), the , and the ; and the , including the (caribou), , th ...

red deer
tooth pendant, an
elk The elk (''Cervus canadensis''), also known as the wapiti, is one of the largest species within the deer Deer or true deer are ed s forming the Cervidae. The two main groups of deer are the , including the , the (wapiti), the , a ...

elk
tooth pendant, a chloritolite bracelet, and a bone needle. However, Denisovans are only confirmed to have inhabited the cave until 55 ka; the dating of Upper Paleolithic artefacts overlaps with modern human migration into Siberia (though there are no occurrences in the Altai region); and the DNA of the only specimen in the cave dating to the time interval (Denisova 14) is too degraded to confirm species identity, so the attribution of these artefacts is unclear.


Tibet

In 1998, five child hand- and footprint impressions were discovered in a
travertine Travertine ( ) is a form of terrestrial limestone Limestone is a common type of carbonate In chemistry, a carbonate is a salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the l ...

travertine
unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * Unit (album), ...
near the Quesang
hot spring A hot spring, hydrothermal spring, or geothermal spring is a spring Spring(s) may refer to: Common uses * Spring (season), a season of the year * Spring (device), a mechanical device that stores energy * Spring (hydrology), a natural source of w ...

hot spring
s in Tibet, which in 2021 were dated to 226 to 169 thousand years ago using uranium decay dating. This is the oldest evidence of human occupation of the Tibetan Plateau, and given the Xiahe mandible is the oldest human fossil from the region (albeit, younger than the Quesang impressions), these may have been made by Denisovan children. The impressions were printed onto a small panel of space, and there is a little overlap between all the prints, so they seem to have been taking care to make new imprints in unused space. If considered art, they are the oldest known examples of
rock art In archaeology Archaeology or archeology is the study of human activity through the recovery and analysis Analysis is the process of breaking a complexity, complex topic or Substance theory, substance into smaller parts in order to g ...
. Similar hand stencils and impressions do not appear again in the archeological record until roughly 40,000 years ago. The footprints comprise four right impressions and one left superimposed on one of the rights. They were probably left by two individuals. The tracks of the individual who superimposed their left onto their right may have scrunched up their toes and wiggled them in the mud, or dug their finger into the toe prints. The footprints average long, which roughly equates to a 7 or 8 year old child by modern human growth rates. There are two sets of handprints (from a left and right hand), which may have been created by an older child unless one of the former two individuals had long fingers. The handprints average , which roughly equates with a 12 year old modern human child, and the middle finger length agrees with a 17 year old modern human. One of the handprints shows an impression of the forearm, and the individual was wiggling their thumb through the mud.


Interbreeding

Analyses of
modern humans Early modern human (EMH) or anatomically modern human (AMH) are terms used to distinguish ''Homo sapiens Humans (''Homo sapiens'') are the most abundant and widespread of , characterized by and large, complex brains. This has enabled ...
genomes show past interbreeding with at least two groups of
archaic humans A number of varieties of ''Homo ''Homo'' () is the genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, definin ...
, Neanderthals and Denisovans, and that such interbreeding events occurred on multiple occasions. Comparisons of the Denisovan, Neanderthal, and modern human genomes has revealed evidence for a complex web of interbreeding among these lineages.


Archaic humans

As much as 17% of the Denisovan genome from Denisova Cave represents DNA from the local Neanderthal population. Denisova 11 was an F1 (first generation) Denisovan/Neanderthal hybrid; the fact that such an individual was found may indicate interbreeding was a common occurrence here. The Denisovan genome shares more derived alleles with the Altai Neanderthal genome from Siberia than with the
Vindija Cave Vindija Cave is an archaeological site associated with Neanderthals and anatomically modern human, modern humans, located in the municipality of Donja Voća, northern Croatia. Three of these Neanderthals were selected as the primary sources for th ...
Neanderthal genome from Croatia or the Mezmaiskaya cave Neanderthal genome from the Caucasus, suggesting that the gene flow came from a population that was more closely related to the local Altai Neanderthals. However, Denny's Denisovan father had the typical Altai Neanderthal
introgression Introgression, also known as introgressive hybridization, in genetics Genetics is a branch of biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, ch ...
, while her Neanderthal mother represented a population more closely related to Vindija Neanderthals. About 4% of the Denisovan genome derives from an unidentified archaic hominin, perhaps the source of the anomalous ancient mtDNA, indicating this species diverged from Neanderthals and humans over a million years ago. The only identified ''Homo'' species of
Late Pleistocene The Late Pleistocene is an unofficial age in the international geologic timescale The geologic time scale (GTS) is a system of chronological datingChronological dating, or simply dating, is the process of attributing to an object or event ...
Asia are ''H. erectus'' and ''H. heidelbergensis''. Before splitting from Neanderthals, their ancestors ("Neandersovans") migrating out of Africa into Europe apparently interbred with an unidentified "superarchaic" human species who were already present there; these superarchaics were the descendants of a very early migration out of Africa around 1.9 mya.


Modern humans

A 2011 study found that Denisovan DNA is prevalent in
Australian Aborigines Aboriginal Australians are the various Indigenous peoples Indigenous peoples, also referred to as first peoples, first nations, aboriginal peoples, native peoples (with these terms often capitalized when referred to relating to specific ...
,
Near Oceania Near Oceania is the part of Oceania settled 35,000 years ago, comprising Australia, New Guinea, and northwestern Island Melanesia: the Bismarck Archipelago and the Solomon Islands (archipelago), Solomon Islands. Prehistory The great nineteenth-ce ...
ns,
Polynesians Polynesians form an ethnolinguistic group An ethnolinguistic group (or ethno-linguistic group) is a group that is unified by both a common ethnicity An ethnic group or ethnicity is a grouping of people who identity (social science), identif ...
,
Fijians Fijians ( fj, iTaukei, lit=Owners (of the land)) are a nation and ethnic group native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historica ...
, Eastern
Indonesians Indonesians (Indonesian language, Indonesian: ''orang Indonesia'') are citizens or people of Indonesia, regardless of their Race (human categorization), racial, ethnicity, ethnic or religious background. There are more than 1,300 ethnicities in ...
and
Mamanwa The Lumad are a group of Austronesian Austronesian may refer to: *The Austronesian languages *The historical Austronesian peoples who carried Austronesian languages on their migrations {{disambiguation ... indigenous people Indigenous ...
ns (from the Philippines); but not in
East Asians East Asian people (East Asians) are the people from East Asia East Asia is the eastern region of Asia, which is defined in both Geography, geographical and culture, ethno-cultural terms. The modern State (polity), states of East Asia incl ...
, western Indonesians,
Jahai people The Jahai or Jehai people are an indigenous people (Orang Asli Orang Asli (''lit''. "First people", "native people", "original people", "aborigines people" or "aboriginal people" in Malay language, Malay) are the heterogeneous Aboriginal peopl ...
(from Malaysia) or
Onge The Onge (also Önge, Ongee, and Öñge) are an Andamanese peoples, Andamanese ethnic group, indigenous to the Andaman Islands in Southeast Asia at the Bay of Bengal, currently administered by India. They are traditionally hunter-gatherers, h ...
(from the
Andaman Islands The Andaman Islands is an archipelago An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster or collection of island An island (or isle) is an isolated piece of habitat that is surrounded b ...

Andaman Islands
). This means that Denisovan introgression occurred within the Pacific region rather than on the Asian mainland, and that ancestors of the latter groups were not present in Southeast Asia at the time, which in turn means that eastern Asia was settled by modern humans in two distinct migrations. In the
Melanesian Melanesian is the adjectival form of Melanesia Melanesia (, ) is a subregion of Oceania in the southwestern Pacific Ocean. It extends from the island of New Guinea in the west to Tonga in the east, and includes the Arafura Sea. The region in ...

Melanesian
genome, about 4–6% or 1.9–3.4% derives from Denisovan introgression. It was reported that New Guineans and Australian Aborigines have the most introgressed DNA, but Australians have less than New Guineans, until a 2021 study discovered 30 to 40% more Denisovan ancestry in Filipino
Negrito The term Negrito () refers to several diverse ethnic groups who inhabit isolated parts of Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia or SEA, is the geographical U ...

Negrito
s than in Papuans, by their estimates roughly 5% of the genome. They recorded the highest levels in the
Aeta The Aeta (Ayta ), Agta, or Dumagat, are collective terms for several Filipino Filipino may refer to: * Something from or related to the Philippines The Philippines (; fil, Pilipinas or ''Filipinas'' ), officially the Republic of the ...
genome. In Papuans, less Denisovan ancestry is seen in the
X chromosome The X chromosome is one of the two sex-determining chromosome A chromosome is a long DNA molecule with part or all of the genome, genetic material of an organism. Most eukaryotic chromosomes include packaging proteins called histones whic ...

X chromosome
than
autosome An autosome is any chromosome that is not a sex chromosome (an allosome). The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosome pairs which may have different structures. The DNA in autosomes is coll ...
s, and some autosomes (such as
chromosome 11 Chromosome 11 is one of the 23 pairs of chromosome A chromosome is a long DNA molecule with part or all of the genome, genetic material of an organism. Most eukaryotic chromosomes include packaging proteins called histones which, aided by ...

chromosome 11
) also have less Denisovan ancestry, which could indicate hybrid incompatibility. The former observation could also be explained by less female Denisovan introgression into modern humans, or more female modern human immigrants who diluted Denisovan X chromosome ancestry. In contrast, 0.2% derives from Denisovan ancestry in mainland Asians and Indigenous peoples of the Americas, Native Americans. South Asians were found to have levels of Denisovan admixture similar to that seen in East Asians. The discovery of the 40,000-year-old Chinese modern human Tianyuan Man lacking Denisovan DNA significantly different from the levels in modern-day East Asians discounts the hypothesis that immigrating modern humans simply diluted Denisovan ancestry whereas Melanesians lived in reproductive isolation. A 2018 study of Han Chinese, Japanese people, Japanese, and Dai people, Dai genomes showed that modern East Asians have DNA from two different Denisovan populations: one similar to the Denisovan DNA found in Papuan genomes, and a second that is closer to the Denisovan genome from Denisova Cave. This could indicate two separate introgression events involving two different Denisovan populations. In South Asian genomes, DNA only came from the same single Denisovan introgression seen in Papuans. A 2019 study found a third wave of Denisovans which introgressed into East Asians. Introgression, also, may not have immediately occurred when modern humans immigrated into the region. The timing of introgression into Oceanian populations likely occurred after Eurasians and Oceanians split roughly 58,000 years ago, and before Papuan and Aboriginal Australians split from each other roughly 37,000 years ago. Given the present day distribution of Denisovan DNA, this may have taken place in Wallacea, though the discovery of a 7,200 year old Toalean culture, Toalean girl (closely related to Papuans and Aboriginal Australians) from Sulawesi carrying Denisovan DNA makes Sundaland another potential candidate. Other early Sunda hunter gatherers so far sequenced carry very little Denisovan DNA, which either means the introgression event did not take place in Sundaland, or Denisovan ancestry was diluted with gene flow from the mainland Asian Hòabìnhian culture and subsequent Neolithic cultures. In other regions of the world, archaic introgression into humans stems from a group of Neanderthals related to those which inhabited
Vindija Cave Vindija Cave is an archaeological site associated with Neanderthals and anatomically modern human, modern humans, located in the municipality of Donja Voća, northern Croatia. Three of these Neanderthals were selected as the primary sources for th ...
, Croatia, as opposed to archaics related to Siberian Neanderthals and Denisovans. However, about 3.3% of the archaic DNA in the modern Icelandic genome descends from the Denisovans, and such a high percentage could indicate a western Eurasian population of Denisovans which introgressed into either Vindija-related Neanderthals or immigrating modern humans. Denisovan genes may have helped early modern humans migrating out of Africa to acclimatize. Although not present in the sequenced Denisovan genome, the distribution pattern and divergence of HLA-B*73 from other HLA type, HLA alleles (involved in the immune system's natural killer cell receptors) has led to the suggestion that it introgressed from Denisovans into modern humans in West Asia. In a 2011 study, half of the HLA alleles of modern Eurasians were shown to represent archaic HLA haplotypes, and were inferred to be of Denisovan or Neanderthal origin. A haplotype of EPAS1 in modern Tibetans, which allows them to live at high elevations in a low-oxygen environment, likely came from Denisovans. Genes related to phospholipid transporters (which are involved in fat metabolism) and to trace amine-associated receptors (involved in smelling) are more active in people with more Denisovan ancestry. Denisovan genes may have conferred a degree of immunity against the G614 mutation of Severe acute respiratory syndrome coronavirus 2, SARS-CoV-2.


See also

* * * * * * * *


References


External links

*
The Denisova Consortium's raw sequence data and alignments

Human Timeline (Interactive)
– Smithsonian Institution, Smithsonian, National Museum of Natural History (August 2016).
Picture of Denisovan molar.
{{Prehistoric technology Homo fossils Human populations Altai Krai Prehistoric Asia Upper Paleolithic