181-589: The Denisovans or Denisova hominins ( / d ə ˈ n iː s ə v ə / də- NEE -sə-və ) are an extinct species or subspecies of archaic human that ranged across Asia during the Lower and Middle Paleolithic , and lived, based on current evidence, from 285 to 25 thousand years ago. Denisovans are known from few physical remains; consequently, most of what is known about them comes from DNA evidence. No formal species name has been established pending more complete fossil material. The first identification of
362-401: A family name is usually derived. The matriline of historical nobility was also called their enatic or uterine ancestry, corresponding to the patrilineal or "agnatic" ancestry. In the late 19th century, almost all prehistorians and anthropologists believed, following Lewis H. Morgan 's influential book Ancient Society , that early human kinship everywhere was matrilineal. This idea
543-438: A food chain who lose their prey. "Species coextinction is a manifestation of one of the interconnectednesses of organisms in complex ecosystems ... While coextinction may not be the most important cause of species extinctions, it is certainly an insidious one." Coextinction is especially common when a keystone species goes extinct. Models suggest that coextinction is the most common form of biodiversity loss . There may be
724-510: A marble ring, an ivory ring, an ivory pendant, a red deer tooth pendant, an 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
905-669: A nautilus to the Royal Society that was more than two feet in diameter, and morphologically distinct from any known living species. Hooke theorized that this was simply because the species lived in the deep ocean and no one had discovered them yet. While he contended that it was possible a species could be "lost", he thought this highly unlikely. Similarly, in 1695, Sir Thomas Molyneux published an account of enormous antlers found in Ireland that did not belong to any extant taxa in that area. Molyneux reasoned that they came from
1086-532: A relict H. erectus 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 . Modern humans contributed mtDNA to the Neanderthal lineage, but not to the Denisovan mitochondrial genomes yet sequenced. The mtDNA sequence from
1267-415: A species or a population is the variety of genetic information in its living members. A large gene pool (extensive genetic diversity ) is associated with robust populations that can survive bouts of intense selection . Meanwhile, low genetic diversity (see inbreeding and population bottlenecks ) reduces the range of adaptions possible. Replacing native with alien genes narrows genetic diversity within
1448-436: A viable population for species preservation and possible future reintroduction to the wild, through use of carefully planned breeding programs . The extinction of one species' wild population can have knock-on effects, causing further extinctions. These are also called "chains of extinction". This is especially common with extinction of keystone species . A 2018 study indicated that the sixth mass extinction started in
1629-484: A "heavy dose" of their pre-existing beliefs including matrilineality. Tuareg women enjoy high status within their society, compared with their Arab counterparts and with other Berber tribes: Tuareg social status is transmitted through women, with residence often matrilocal . Most women could read and write, while most men were illiterate, concerning themselves mainly with herding livestock and other male activities. The livestock and other movable property were owned by
1810-443: 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. Analyses of the modern human genomes indicate past interbreeding with at least two groups of archaic humans, Neanderthals and Denisovans, and that such interbreeding events occurred on multiple occasions. Comparisons of
1991-480: 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. Denisovans may represent a new species of Homo or an archaic subspecies of Homo sapiens (modern humans), but there are too few fossils to erect a proper taxon . Proactively proposed species names for Denisovans are H. denisova or H. altaiensis . Chinese researchers suggest
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#17327574029102172-616: A Denisovan individual occurred in 2010, based on mitochondrial DNA (mtDNA) extracted from a juvenile female finger bone excavated from the Siberian Denisova Cave in the Altai Mountains in 2008. Nuclear DNA indicates close affinities with Neanderthals . 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
2353-517: 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 analysis on haplotype lengths, Jacobs calculated introgression into modern humans occurred about 29,900 years ago with the Denisovan population ancestral to New Guineans; and 45,700 years ago with
2534-479: A Lazarus species when extant individuals were described in 2019. Attenborough's long-beaked echidna ( Zaglossus attenboroughi ) is an example of a Lazarus species from Papua New Guinea that had last been sighted in 1962 and believed to be possibly extinct, until it was recorded again in November 2023. Some species currently thought to be extinct have had continued speculation that they may still exist, and in
2715-503: A cascade of coextinction across the trophic levels . Such effects are most severe in mutualistic and parasitic relationships. An example of coextinction is the Haast's eagle and the moa : the Haast's eagle was a predator that became extinct because its food source became extinct. The moa were several species of flightless birds that were a food source for the Haast's eagle. Extinction as
2896-429: A common ancestor with modern horses. Pseudoextinction is much easier to demonstrate for larger taxonomic groups. A Lazarus taxon or Lazarus species refers to instances where a species or taxon was thought to be extinct, but was later rediscovered. It can also refer to instances where large gaps in the fossil record of a taxon result in fossils reappearing much later, although the taxon may have ultimately become extinct at
3077-540: A different household. According to this source of further information about the Akan, "A man is strongly related to his mother's brother (wɔfa) but only weakly related to his father's brother. This must be viewed in the context of a polygamous society in which the mother/child bond is likely to be much stronger than the father/child bond. As a result, in inheritance, a man's nephew (sister's son) will have priority over his own son. Uncle-nephew relationships therefore assume
3258-531: A different pattern, however: Example 1. Members of the (matrilineal) clan culture Minangkabau do not even have a surname or family name , see this culture's own section below. In contrast, members do have a clan name , which is important in their lives although not included in the member's name. Instead, one's name is just one's given name . Example 2. Members of the (matrilineal) clan culture Akan , see its own section below, also do not have matrilineal surnames and likewise their important clan name
3439-442: A dominant position." Certain other aspects of the Akan culture are determined patrilineally rather than matrilineally. There are 12 patrilineal Ntoro (which means spirit) groups, and everyone belongs to their father's Ntoro group but not to his (matrilineal) family lineage and abusua . Each patrilineal Ntoro group has its own surnames, taboos, ritual purifications, and etiquette. A recent (2001) book provides this update on
3620-399: A fact that was accepted by most scientists. The primary debate focused on whether this turnover caused by extinction was gradual or abrupt in nature. Cuvier understood extinction to be the result of cataclysmic events that wipe out huge numbers of species, as opposed to the gradual decline of a species over time. His catastrophic view of the nature of extinction garnered him many opponents in
3801-425: 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
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#17327574029103982-537: A high percentage (roughly 5%) occurring in Melanesians , Aboriginal Australians , and Filipino Negritos . This distribution suggests that there were Denisovan populations across Asia. 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
4163-708: A higher risk of extinction and die out faster than less sexually dimorphic species, the least sexually dimorphic species surviving for millions of years while the most sexually dimorphic species die out within mere thousands of years. Earlier studies based on counting the number of currently living species in modern taxa have shown a higher number of species in more sexually dimorphic taxa which have been interpreted as higher survival in taxa with more sexual selection, but such studies of modern species only measure indirect effects of extinction and are subject to error sources such as dying and doomed taxa speciating more due to splitting of habitat ranges into more small isolated groups during
4344-405: A large range, a lack of individuals of both sexes (in sexually reproducing species), or other reasons. Pinpointing the extinction (or pseudoextinction ) of a species requires a clear definition of that species . If it is to be declared extinct, the species in question must be uniquely distinguishable from any ancestor or daughter species, and from any other closely related species. Extinction of
4525-607: A later point. The coelacanth , a fish related to lungfish and tetrapods , is an example of a Lazarus taxon that was known only from the fossil record and was considered to have been extinct since the end of the Cretaceous Period . In 1938, however, a living specimen was found off the Chalumna River (now Tyolomnqa) on the east coast of South Africa. Calliostoma bullatum , a species of deepwater sea snail originally described from fossils in 1844 proved to be
4706-769: 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. In a 2024 study, scientist Danat Yermakovich, of the University of Tartu , discovered that people living at different elevations in Papua New Guinea have differences in Denisovan DNA; with people living in
4887-423: A long, broad, and projecting face; large nose; sloping forehead; protruding jaw; elongated and flattened skull; and wide chest and hips. 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
5068-456: 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 SARS-CoV-2 . Denisovan introgressions may have influenced
5249-594: A mathematical model that falls in all positions. By contrast, conservation biology uses the extinction vortex model to classify extinctions by cause. When concerns about human extinction have been raised, for example in Sir Martin Rees ' 2003 book Our Final Hour , those concerns lie with the effects of climate change or technological disaster. Human-driven extinction started as humans migrated out of Africa more than 60,000 years ago. Currently, environmental groups and some governments are concerned with
5430-461: A million years ago. The only identified Homo species of Late Pleistocene Asia are H. erectus and H. heidelbergensis , though in 2021, specimens allocated to the latter species were reclassified as H. longi and H. daliensis . Before splitting from Neanderthals, their ancestors ("Neandersovans") migrating into Europe apparently interbred with an unidentified "superarchaic" human species who were already present there; these superarchaics were
5611-485: A mutation rate of 1 × 10 or 0.5 × 10 per base pair (bp) per year, the Neanderthal/Denisovan split occurred around either 236–190,000 or 473–381,000 years ago respectively. Using 1.1 × 10 per generation with a new generation every 29 years, the time is 744,000 years ago. Using 5 × 10 nucleotide site per year, it is 616,000 years ago. Using the latter dates, the split had likely already occurred by
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5792-456: A natural part of the evolutionary process. Only recently have extinctions been recorded and scientists have become alarmed at the current high rate of extinctions . Most species that become extinct are never scientifically documented. Some scientists estimate that up to half of presently existing plant and animal species may become extinct by 2100. A 2018 report indicated that the phylogenetic diversity of 300 mammalian species erased during
5973-441: A new mega-predator or by transporting animals and plants from one part of the world to another. Such introductions have been occurring for thousands of years, sometimes intentionally (e.g. livestock released by sailors on islands as a future source of food) and sometimes accidentally (e.g. rats escaping from boats). In most cases, the introductions are unsuccessful, but when an invasive alien species does become established,
6154-478: A particular ancestress. Several lineages are grouped into a political unit headed by a chief and a council of elders, each of whom is the elected head of a lineage – which itself may include multiple extended-family households. Public offices are thus vested in the lineage, as are land tenure and other lineage property. In other words, lineage property is inherited only by matrilineal kin. "The principles governing inheritance stress sex, generation and age – that
6335-610: A population a higher chance in the short term of surviving an adverse change in conditions. Effects that cause or reward a loss in genetic diversity can increase the chances of extinction of a species. Population bottlenecks can dramatically reduce genetic diversity by severely limiting the number of reproducing individuals and make inbreeding more frequent. Extinction sometimes results for species evolved to specific ecologies that are subjected to genetic pollution —i.e., uncontrolled hybridization , introgression and genetic swamping that lead to homogenization or out-competition from
6516-465: A population more closely related to Vindija Neanderthals. Denisova 25, dated to 200ka, is estimated to have inherited 5% of his genome from a previously unknown population of Neanderthals, and came from a different population of Denisovans than the younger samples. 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
6697-407: A race of animals to become extinct. A series of fossils were discovered in the late 17th century that appeared unlike any living species. As a result, the scientific community embarked on a voyage of creative rationalization, seeking to understand what had happened to these species within a framework that did not account for total extinction. In October 1686, Robert Hooke presented an impression of
6878-502: A reduction in agricultural productivity. Furthermore, increased erosion contributes to poorer water quality by elevating the levels of sediment and pollutants in rivers and streams. Habitat degradation through toxicity can kill off a species very rapidly, by killing all living members through contamination or sterilizing them. It can also occur over longer periods at lower toxicity levels by affecting life span, reproductive capacity, or competitiveness. Habitat degradation can also take
7059-499: A result of climate change has been confirmed by fossil studies. Particularly, the extinction of amphibians during the Carboniferous Rainforest Collapse , 305 million years ago. A 2003 review across 14 biodiversity research centers predicted that, because of climate change, 15–37% of land species would be "committed to extinction" by 2050. The ecologically rich areas that would potentially suffer
7240-471: A social actuality of sexual equality." According to LeBow (based on Schlegel's work), in the Hopi, "gender roles ... are egalitarian .... [and] [n]either sex is inferior." LeBow concluded that Hopi women "participate fully in ... political decision-making." According to Schlegel, "the Hopi no longer live as they are described here" and "the attitude of female superiority is fading". Schlegel said
7421-479: A species (or replacement by a daughter species) plays a key role in the punctuated equilibrium hypothesis of Stephen Jay Gould and Niles Eldredge . In ecology , extinction is sometimes used informally to refer to local extinction , in which a species ceases to exist in the chosen area of study, despite still existing elsewhere. Local extinctions may be made good by the reintroduction of individuals of that species taken from other locations; wolf reintroduction
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7602-439: A species may come suddenly when an otherwise healthy species is wiped out completely, as when toxic pollution renders its entire habitat unliveable; or may occur gradually over thousands or millions of years, such as when a species gradually loses out in competition for food to better adapted competitors. Extinction may occur a long time after the events that set it in motion, a phenomenon known as extinction debt . Assessing
7783-404: A species or group of species. "Just as each species is unique", write Beverly and Stephen C. Stearns , "so is each extinction ... the causes for each are varied—some subtle and complex, others obvious and simple". Most simply, any species that cannot survive and reproduce in its environment and cannot move to a new environment where it can do so, dies out and becomes extinct. Extinction of
7964-518: A subsequent report, IPBES listed unsustainable fishing, hunting and logging as being some of the primary drivers of the global extinction crisis. In June 2019, one million species of plants and animals were at risk of extinction. At least 571 plant species have been lost since 1750, but likely many more. The main cause of the extinctions is the destruction of natural habitats by human activities, such as cutting down forests and converting land into fields for farming. A dagger symbol (†) placed next to
8145-811: A variant region around the EPAS1 gene that in Tibetans 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 . 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. Early Middle Paleolithic stone tools from Denisova Cave included cores , scrapers , denticulate tools , and notched tools, deposited about 287±41 thousand years ago in
8326-519: A version of male-preference matrilineal seniority , favoring brothers over sisters in the current generation (but allowing sisters to inherit if no brothers remained), but passing to the next generation through the eldest female line. In A Map of Virginia John Smith of Jamestown explains: His [ Chief Powhatan 's] kingdome descendeth not to his sonnes nor children: but first to his brethren, whereof he hath 3 namely Opitchapan, Opechancanough , and Catataugh; and after their decease to his sisters. First to
8507-403: Is a line of descent from a female ancestor to a descendant of either gender in which the individuals in all intervening generations are mothers. In a matrilineal descent system , an individual is considered to belong to the same descent group as their mother. This ancient matrilineal descent pattern is in contrast to the currently more popular pattern of patrilineal descent from which
8688-759: Is also matrilocal , a man will exercise guardianship rights not over the children he fathers but over his sisters' children, who are viewed as 'his own flesh'. These children's biological father – unlike an uncle who is their mother's brother and thus their caregiver – is in some sense a 'stranger' to them, even when affectionate and emotionally close. According to Steven Pinker , attributing to Kristen Hawkes, among foraging groups matrilocal societies are less likely to commit female infanticide than are patrilocal societies. Some 20 million Akan live in Africa, particularly in Ghana and Ivory Coast . (See as well their subgroups,
8869-523: Is also evidence to suggest that this event was preceded by another mass extinction, known as Olson's Extinction . The Cretaceous–Paleogene extinction event (K–Pg) occurred 66 million years ago, at the end of the Cretaceous period; it is best known for having wiped out non-avian dinosaurs , among many other species. According to a 1998 survey of 400 biologists conducted by New York 's American Museum of Natural History , nearly 70% believed that
9050-444: Is an example of this. Species that are not globally extinct are termed extant . Those species that are extant, yet are threatened with extinction, are referred to as threatened or endangered species . Currently, an important aspect of extinction is human attempts to preserve critically endangered species. These are reflected by the creation of the conservation status "extinct in the wild" (EW) . Species listed under this status by
9231-585: Is difficult to demonstrate unless one has a strong chain of evidence linking a living species to members of a pre-existing species. For example, it is sometimes claimed that the extinct Hyracotherium , which was an early horse that shares a common ancestor with the modern horse , is pseudoextinct, rather than extinct, because there are several extant species of Equus , including zebra and donkey ; however, as fossil species typically leave no genetic material behind, one cannot say whether Hyracotherium evolved into more modern horse species or merely evolved from
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#17327574029109412-593: Is discussed in the subsection Role of the Tokoor of one of the above-listed main articles. The Tuareg (Arabic:طوارق, sometimes spelled Touareg in French, or Twareg in English) are a large Berber ethnic confederation found across several nations in north Africa, including Niger , Mali and Algeria . The Tuareg are clan -based, and are (still, in 2007) "largely matrilineal". The Tuareg are Muslim , but mixed with
9593-417: Is estimated as 100 to 1,000 times "background" rates (the average extinction rates in the evolutionary time scale of planet Earth), faster than at any other time in human history, while future rates are likely 10,000 times higher. However, some groups are going extinct much faster. Biologists Paul R. Ehrlich and Stuart Pimm , among others, contend that human population growth and overconsumption are
9774-414: Is estimated that there are currently around 8.7 million species of eukaryotes globally, and possibly many times more if microorganisms , like bacteria , are included. Notable extinct animal species include non-avian dinosaurs , saber-toothed cats , dodos , mammoths , ground sloths , thylacines , trilobites , golden toads , and passenger pigeons . Through evolution , species arise through
9955-430: 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 the range of any Homo species except H. habilis and H. rudolfensis , and is more like those of australopithecines . The second molar is larger than those of modern humans and Neanderthals, and is more similar to those of H. erectus and H. habilis . Like Neanderthals,
10136-417: Is less common than among farmers. So for example, among the pygmies of Aka, which includes Biaka and Benzene, a young couple usually settles in her husband's camp after the birth of their first child. However, the husband can stay in the wife's community, where one of his brothers or sisters can join him. This can happen in societies where the bride's service is practiced, or in any other societies. According to
10317-404: Is not included in their name. However, members' names do commonly include second names which are called surnames but which are not routinely passed down from either father or mother to all their children as a family name . Note well that if a culture did include one's clan name in one's name and routinely handed it down to all children in the descent group then it would automatically be
10498-400: Is that when sisters and their mothers help each other with childcare, the descent line tends to be matrilineal rather than patrilineal. Biological anthropologists are now widely agreed that cooperative childcare was a development crucial in making possible the evolution of the unusually large human brain and characteristically human psychology. Although others refute the claims of supporters of
10679-592: Is the destruction of ocean floors by bottom trawling . Diminished resources or introduction of new competitor species also often accompany habitat degradation. Global warming has allowed some species to expand their range, bringing competition to other species that previously occupied that area. Sometimes these new competitors are predators and directly affect prey species, while at other times they may merely outcompete vulnerable species for limited resources. Vital resources including water and food can also be limited during habitat degradation, leading to extinction. In
10860-578: Is the earliest recorded human presence on the Tibetan Plateau. Though their remains have been identified in only these three locations, traces of Denisovan DNA in modern humans suggest they ranged across East Asia , and potentially western Eurasia. In 2019, geneticist Guy Jacobs and colleagues identified three distinct populations of Denisovans responsible for the introgression into modern populations now native to, respectively: Siberia and East Asia; New Guinea and nearby islands; and Oceania and, to
11041-525: Is the most important determinant of genus extinction at background rates but becomes increasingly irrelevant as mass extinction arises. Limited geographic range is a cause both of small population size and of greater vulnerability to local environmental catastrophes. Extinction rates can be affected not just by population size, but by any factor that affects evolvability , including balancing selection , cryptic genetic variation , phenotypic plasticity , and robustness . A diverse or deep gene pool gives
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#173275740291011222-473: Is the oldest, followed by Denisova 8, while Denisova 3 and Denisova 4 were roughly contemporaneous. In 2024, scientists announced the sequence of Denisova 25, which was in a layer dated to 200ka. 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 and Denisova 25 genomes were intact. The Denisova 3 sample
11403-431: Is to say, men come before women and seniors before juniors." When a woman's brothers are available, a consideration of generational seniority stipulates that the line of brothers be exhausted before the right to inherit lineage property passes down to the next senior genealogical generation of sisters' sons. Finally, "it is when all possible male heirs have been exhausted that the females" may inherit. Each lineage controls
11584-897: The Trobrianders , Dobu and Nagovisi of Melanesia; the Nairs , some Thiyyas & Muslims of Kerala and the Mogaveeras , Billavas & the Bunts of Karnataka in south India ; the Khasi , Jaintia and Garo of Meghalaya in northeast India and Bangladesh ; the Ngalops and Sharchops of Bhutan ; the Mosuo of China ; the Kayah of Southeast Asia, the Picti of Scotland ,
11765-483: The Annamite Mountains since 2008, was directed by local children to the site Tam Ngu Hao 2 ("Cobra Cave") where they recovered a human tooth. The tooth (catalogue number TNH2-1) developmentally matches a 3.5 to 8.5 year old, and a lack of amelogenin (a protein on the Y chromosome ) suggests it belonged to a girl barring extreme degradation of the protein over a long period of time. Dental proteome analysis
11946-508: The Ashanti , also called Asante, Akyem , Bono , Fante , Akwamu .) Many but not all of the Akan still (2001) practice their traditional matrilineal customs, living in their traditional extended family households, as follows. The traditional Akan economic, political and social organization is based on maternal lineages, which are the basis of inheritance and succession. A lineage is defined as all those related by matrilineal descent from
12127-1183: The Basques of Spain and France ; the Ainu of Japan , the Akan including the Ashanti , Bono , Akwamu , Fante of Ghana ; most groups across the so-called " matrilineal belt " of south-central Africa; the Nubians of Southern Egypt & Sudan and the Tuareg of west and north Africa; the Serer of Senegal , The Gambia and Mauritania . Most of the example cultures in this article are based on (matrilineal) clans . Any clan might possibly contain from one to several or many descent groups or family groups – i.e., any matrilineal clan might be descended from one or several or many unrelated female ancestors. Also, each such descent group might have its own family name or surname , as one possible cultural pattern. The following two example cultures each follow
12308-620: The Cegandum and Kagaw , whose historical account is enshrined in Serer religion, mythology and traditions . In Serer culture, inheritance is both matrilineal and patrilineal. It all depends on the asset being inherited – i.e. whether the asset is a paternal asset – requiring paternal inheritance ( kucarla ) or a maternal asset – requiring maternal inheritance ( den yaay or ƭeen yaay ). The actual handling of these maternal assets (such as jewelry, land, livestock, equipment or furniture, etc.)
12489-483: The International Union for Conservation of Nature (IUCN) are not known to have any living specimens in the wild and are maintained only in zoos or other artificial environments. Some of these species are functionally extinct, as they are no longer part of their natural habitat and it is unlikely the species will ever be restored to the wild. When possible, modern zoological institutions try to maintain
12670-616: The Joos matriclan which also became a dynasty in Waalo (Senegal). Some matriclans or maternal clans form part of Serer medieval and dynastic history, such as the Guelowars . The most revered clans tend to be rather ancient and form part of Serer ancient history . These proto-Serer clans hold great significance in Serer religion and mythology . Some of these proto-Serer matriclans include
12851-485: The Late Pleistocene could take up to 5 to 7 million years to restore mammal diversity to what it was before the human era. Extinction of a parent species where daughter species or subspecies are still extant is called pseudoextinction or phyletic extinction. Effectively, the old taxon vanishes, transformed ( anagenesis ) into a successor, or split into more than one ( cladogenesis ). Pseudoextinction
13032-629: The Tibetan Plateau in China. Known as the Xiahe mandible , the fossil became part of the collection of Lanzhou University , where it remained unstudied until 2010. It was determined by ancient protein analysis to contain 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 crust enshrouding
13213-460: The U.S. became a nation, operated by The Great Binding Law of Peace , a constitution by which women retained matrilineal-rights and participated in the League's political decision-making, including deciding whether to proceed to war, through what may have been a matriarchy or "gyneocracy". The dates of this constitution's operation are unknown: the League was formed in approximately 1000–1450, but
13394-697: The abusua framework presented above. The Berber inhabitants of Gran Canaria island had developed a matrilineal society by the time the Canary Islands and their people, called Guanches , were conquered by the Spanish. The Serer people of Senegal , the Gambia and Mauritania are patrilineal ( simanGol in Serer language ) as well as matrilineal ( tim ). There are several Serer matriclans and matriarchs . Some of these matriarchs include Fatim Beye (1335) and Ndoye Demba (1367) – matriarchs of
13575-471: The family name or surname for one's descent group (as well as for all other descent groups in one's clan). While a mother normally takes care of her own children in all cultures, in some matrilineal cultures an "uncle-father" will take care of his nieces and nephews instead: in other words social fathers here are uncles. There is not a necessary connection between the role of father and genitor. In many such matrilineal cultures, especially where residence
13756-525: The national Constitution as Scheduled Tribes, "some ... [are] matriarchal and matrilineal" "and thus have been known to be more egalitarian." Several Hindu communities in South India practiced matrilineality, especially the Nair (or Nayar ) and Tiyyas in the state of Kerala , and the Bunts and Billava in the states of Karnataka . The system of inheritance was known as Marumakkathayam in
13937-410: The slender-billed curlew ( Numenius tenuirostris ), not seen since 2007. As long as species have been evolving, species have been going extinct. It is estimated that over 99.9% of all species that ever lived are extinct. The average lifespan of a species is 1–10 million years, although this varies widely between taxa. A variety of causes can contribute directly or indirectly to the extinction of
14118-488: The strata of the Paris basin. They saw alternating saltwater and freshwater deposits, as well as patterns of the appearance and disappearance of fossils throughout the record. From these patterns, Cuvier inferred historic cycles of catastrophic flooding, extinction, and repopulation of the earth with new species. Cuvier's fossil evidence showed that very different life forms existed in the past than those that exist today,
14299-601: The 1970s and 1980s, a range of feminist scholars often attempted to revive it. In recent years, evolutionary biologists , geneticists and palaeoanthropologists have been reassessing the issues, many citing genetic and other evidence that early human kinship may have been matrilineal after all. One crucial piece of indirect evidence has been genetic data suggesting that over thousands of years, women among sub-Saharan African hunter-gatherers have chosen to reside postmaritally not with their husbands' family but with their own mother and other natal kin. Another line of argument
14480-855: The 1970s by Soviet paleontologist Nikolai Ovodov, who was looking for remains of canids . In 2008, Michael Shunkov from the Russian Academy of Sciences and other Russian archaeologists from the Institute of Archaeology and Ethnography of the Siberian Branch of the Russian Academy of Sciences in Novosibirsk Akademgorodok investigated the cave and found the finger bone of a juvenile female hominin originally dated to 50–30,000 years ago. The estimate has changed to 76,200–51,600 years ago. The specimen
14661-639: The 20 biodiversity goals laid out by the Aichi Biodiversity Targets in 2010, only 6 were "partially achieved" by the deadline of 2020. The report warned that biodiversity will continue to decline if the status quo is not changed, in particular the "currently unsustainable patterns of production and consumption, population growth and technological developments". In a 2021 report published in the journal Frontiers in Conservation Science , some top scientists asserted that even if
14842-442: 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 , and Dai genomes showed that modern East Asians have DNA from two different Denisovan populations: one similar to
15023-451: The Aichi Biodiversity Targets set for 2020 had been achieved, it would not have resulted in a significant mitigation of biodiversity loss. They added that failure of the global community to reach these targets is hardly surprising given that biodiversity loss is "nowhere close to the top of any country's priorities, trailing far behind other concerns such as employment, healthcare, economic growth, or currency stability." For much of history,
15204-469: The Akan: Some families are changing from the above abusua structure to the nuclear family . Housing, childcare, education, daily work, and elder care etc. are then handled by that individual family rather than by the abusua or clan, especially in the city. The above taboo on marriage within one's abusua is sometimes ignored, but "clan membership" is still important, with many people still living in
15385-599: The Altai Neanderthal genome from Siberia than with the Vindija Cave 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 , while her Neanderthal mother represented
15566-682: The Arabian peoples (first of all among the Amorites of Yemen, and among some strata of Nabateans in Northern Arabia); A modern example from South Africa is the order of succession to the position of the Rain Queen in a culture of matrilineal primogeniture : not only is dynastic descent reckoned through the female line, but only females are eligible to inherit. In some traditional societies and cultures, membership in their groups
15747-554: The Bribri people of Costa Rica and Panama is matrilineal; that is, a child's clan is determined by the clan his or her mother belongs to. Only women can inherit land. The social organization of the Cabécar people of Costa Rica is predicated on matrilineal clans in which the mother is the head of household. Each matrilineal clan controls marriage possibilities, regulates land tenure, and determines property inheritance for its members. In
15928-596: 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
16109-472: The Denisovan, Neanderthal, and modern human genomes have revealed evidence of a complex web of interbreeding among these lineages. 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
16290-726: The Denisovans based on the similarity between the type specimen's molar and that of the Xiahe mandible. KU131206 Sequenced 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 and Svante Pääbo from the Max Planck Institute for Evolutionary Anthropology in Leipzig , Germany. Denisova 3's mtDNA differs from that of modern humans by 385 bases ( nucleotides ) out of approximately 16,500, whereas
16471-457: The Denisovans were members of Homo longi , and the idea has been supported by the palaeontologist Chris Stringer . Denisova Cave is located in Altai Krai , Russia, in south-central Siberia , on the western edges of the Altai Mountains . It is named after Denis (Dyonisiy), a Russian Old Believer hermit who lived there in the 18th century. The cave was first inspected for fossils in
16652-618: The Earth is currently in the early stages of a human-caused mass extinction, known as the Holocene extinction . In that survey, the same proportion of respondents agreed with the prediction that up to 20% of all living populations could become extinct within 30 years (by 2028). A 2014 special edition of Science declared there is widespread consensus on the issue of human-driven mass species extinctions. A 2020 study published in PNAS stated that
16833-579: 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 ka . Neanderthals were also present 193±12 ka and 97±11 ka, possibly concurrently with Denisovans. The fossils of multiple distinct Denisovan individuals from Denisova Cave have been identified through their ancient DNA (aDNA): Denisova 2, 3, 4, 8, 11 , and 25. An mtDNA-based phylogenetic analysis of these individuals suggested that Denisova 2
17014-516: The Hopi "were and still are matrilinial" and "the household ... was matrilocal". Schlegel explains why there was female superiority as that the Hopi believed in "life as the highest good ... [with] the female principle ... activated in women and in Mother Earth ;... as its source" and that the Hopi "were not in a state of continual war with equally matched neighbors" and "had no standing army" so that "the Hopi lacked
17195-475: The Lenape prevented permanent settlement beyond what is now Jersey City. "Early Europeans who first wrote about these Indians found matrilineal social organization to be unfamiliar and perplexing. As a result, the early records are full of 'clues' about early Lenape society, but were usually written by observers who did not fully understand what they were seeing." The Mandan people of the northern Great Plains of
17376-655: 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
17557-584: The North American moose and that the animal had once been common on the British Isles . Rather than suggest that this indicated the possibility of species going extinct, he argued that although organisms could become locally extinct, they could never be entirely lost and would continue to exist in some unknown region of the globe. The antlers were later confirmed to be from the extinct deer Megaloceros . Hooke and Molyneux's line of thinking
17738-735: 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. In the Melanesian genome, about 4–6% or 1.9–3.4% derives from Denisovan introgression. Prior to 2021, New Guineans and Australian Aborigines were reported to have the most introgressed DNA, but Australians have less than New Guineans. A 2021 study discovered 30 to 40% more Denisovan ancestry in Aeta people in
17919-522: The Paris basin, could be formed by a slow rise and fall of sea levels . The concept of extinction was integral to Charles Darwin 's On the Origin of Species , with less fit lineages disappearing over time. For Darwin, extinction was a constant side effect of competition . Because of the wide reach of On the Origin of Species , it was widely accepted that extinction occurred gradually and evenly (a concept now referred to as background extinction ). It
18100-1026: The Philippines than in Papuans , estimated as about 5% of the genome. The Aeta Magbukon in Luzon have the highest known proportion of Denisovan ancestry of any population in the world. In Papuans, less Denisovan ancestry is seen in the X chromosome than autosomes , and some autosomes (such as 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 Native Americans . South Asians were found to have levels of Denisovan admixture similar to that seen in East Asians. The discovery of
18281-526: 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. Alternately, high Denisovan DNA admixture in modern Papuan populations may simply represent higher mixing among the original ancestors of Papuans prior to crossing the Wallace line. Icelanders also have an anomalously high Denisovan heritage, which could have stemmed from
18462-502: The South Chamber, though some layers of the East Chamber seem to have been disturbed. There was blade 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 tools and ornaments:
18643-456: The Tibetan Plateau, and since the Xiahe mandible is the oldest human fossil from the region (though 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 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
18824-477: The United States government, to force the removal of Native Americans , many of whom relied on the bison for food. Matrilineal Matrilineality is the tracing of kinship through the female line. It may also correlate with a social system in which each person is identified with their matriline, their mother's lineage , and which can involve the inheritance of property and titles. A matriline
19005-472: The United States historically lived in matrilineal extended family lodges. The Naso (Teribe or Térraba) people of Panama and Costa Rica describe themselves as a matriarchal community, although their monarchy has traditionally been inherited in the male line. The Navajo people of the American southwest are a matrilineal society in which kinship, children, livestock and family histories are passed down through
19186-482: The ZooMS analysis was there was no evidence of any other human group having occupied the cave. Other bone fragments included a large number of blue sheep , wild yaks , woolly rhino , spotted hyena , marmots , and other small mammals and birds. Examination of the animal bone surfaces indicates the Denisovans removed meat and bone marrow from the bones and also show the humans used them as raw material to make tools. There
19367-429: The accumulation of slightly deleterious mutations , then a population will go extinct. Smaller populations have fewer beneficial mutations entering the population each generation, slowing adaptation. It is also easier for slightly deleterious mutations to fix in small populations; the resulting positive feedback loop between small population size and low fitness can cause mutational meltdown . Limited geographic range
19548-402: 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,
19729-583: The background. Originally, Chinese surnames were derived matrilineally, although by the time of the Shang dynasty (1600 to 1046 BCE ) they had become patrilineal. Archaeological data supports the theory that during the Neolithic period (7000 to 2000 BCE ) in China, Chinese matrilineal clans evolved into the usual patrilineal families by passing through a transitional patrilineal clan phase. Evidence includes some "richly furnished" tombs for young women in
19910-470: The cave dating to the time interval (Denisova 14) is too degraded to confirm species identity, so the attribution of these artefacts is unclear. In 1998, five child hand- and footprint impressions were discovered in a travertine unit near the Quesang hot springs in Tibet; in 2021, they were dated to 226 to 169 thousand years ago using uranium decay dating. This is the oldest evidence of human occupation of
20091-600: The consequences can be catastrophic. Invasive alien species can affect native species directly by eating them, competing with them, and introducing pathogens or parasites that sicken or kill them; or indirectly by destroying or degrading their habitat. Human populations may themselves act as invasive predators. According to the "overkill hypothesis", the swift extinction of the megafauna in areas such as Australia (40,000 years before present), North and South America (12,000 years before present), Madagascar , Hawaii (AD 300–1000), and New Zealand (AD 1300–1500), resulted from
20272-641: The constitution was oral until written in about 1880. The League still exists. Other Iroquoian-speaking peoples such as the Wyandot and the Meherrin , that were never part of the Iroquois League, nevertheless have traditionally possessed a matrilineal family structure. The Kogi people of northern Colombia practice bilateral inheritance, with certain rights, names or associations descending matrilineally. Occupied for 10,000 years by Native Americans ,
20453-418: The contemporary extinction crisis "may be the most serious environmental threat to the persistence of civilization, because it is irreversible." Biologist E. O. Wilson estimated in 2002 that if current rates of human destruction of the biosphere continue, one-half of all plant and animal species of life on earth will be extinct in 100 years. More significantly, the current rate of global species extinctions
20634-556: The data above, some scientists also say that kinship and residence in hunter-gatherer societies are complex and multifaceted. For example, when re-checking past data (which were not very reliable), the researchers note that about 40% of the groups were bilocal, 22.9% were matrilocal and 25% were patrilocal. A number of scientists also advocate multilocality, refuting the concepts of exceptional matrilocality (matrilineality) or patrilocality (patrilineality). Matrilineal surnames are names transmitted from mother to daughter, in contrast to
20815-541: The death of its last member if it loses the capacity to reproduce and recover. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa , where a species presumed extinct abruptly "reappears" (typically in the fossil record ) after a period of apparent absence. More than 99% of all species that ever lived on Earth , amounting to over five billion species, are estimated to have died out. It
20996-476: The deliberate destruction of some species, such as dangerous viruses , and the total destruction of other problematic species has been suggested. Other species were deliberately driven to extinction, or nearly so, due to poaching or because they were "undesirable", or to push for other human agendas. One example was the near extinction of the American bison , which was nearly wiped out by mass hunts sanctioned by
21177-630: The descendants of a very early migration out of Africa around 1.9 mya. A 2011 study found that Denisovan DNA is prevalent in Papuans , Aboriginal Australians , Near Oceanians , Polynesians , Fijians , Eastern Indonesians , and Aeta (from the Philippines); but not in East Asians , western Indonesians, Jahai people (from Malaysia), or Onge (from the Andaman Islands ). This may suggest that Denisovan introgression occurred within
21358-565: 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 (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
21539-448: The difference between modern humans and Neanderthals is around 202 bases. In comparison, the difference between chimpanzees 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
21720-605: The distribution pattern and divergence of HLA-B*73 from other 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
21901-481: The early Neolithic Yangshao culture, whose multiple other collective burials imply a matrilineal clan culture. Toward the late Neolithic period, when burials were apparently of couples, "a reflection of patriarchy", an increasing elaboration of presumed chiefs' burials is reported. Relatively isolated ethnic minorities such as the Mosuo (Na) in southwestern China are highly matrilineal. Of communities recognized in
22082-695: The eldest sister, then to the rest: and after them to the heires male and female of the eldest sister; but never to the heires of the males. The Upper Kuskokwim people are the original inhabitants of the Upper Kuskokwim River basin. They speak an Athabaskan language more closely related to Tanana than to the language of the Lower Kuskokkwim River basin. They were traditionally hunter-gatherers who lived in matrilineal semi-nomadic bands. The Wayuu people of Colombia and Venezuela live in matrilineal clans, with paternal relationships in
22263-403: The endangered wild water buffalo is most threatened with extinction by genetic pollution from the abundant domestic water buffalo ). Such extinctions are not always apparent from morphological (non-genetic) observations. Some degree of gene flow is a normal evolutionary process; nevertheless, hybridization (with or without introgression) threatens rare species' existence. The gene pool of
22444-409: The ends used to scrape), burins , 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 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
22625-591: The event of rediscovery would be considered Lazarus species. Examples include the thylacine , or Tasmanian tiger ( Thylacinus cynocephalus ), the last known example of which died in Hobart Zoo in Tasmania in 1936; the Japanese wolf ( Canis lupus hodophilax ), last sighted over 100 years ago; the American ivory-billed woodpecker ( Campephilus principalis ), with the last universally accepted sighting in 1944; and
22806-443: The extinction crisis. According to the International Union for Conservation of Nature (IUCN), 784 extinctions have been recorded since the year 1500, the arbitrary date selected to define "recent" extinctions, up to the year 2004; with many more likely to have gone unnoticed. Several species have also been listed as extinct since 2004. If adaptation increasing population fitness is slower than environmental degradation plus
22987-475: The extinction of species caused by humanity, and they try to prevent further extinctions through a variety of conservation programs. Humans can cause extinction of a species through overharvesting , pollution , habitat destruction , introduction of invasive species (such as new predators and food competitors ), overhunting, and other influences. Explosive, unsustainable human population growth and increasing per capita consumption are essential drivers of
23168-673: The female. In marriage the groom moved to live with the brides family. Children also came from their mother's clan living in hogans of the females family. The Tanana Athabaskan people, the original inhabitants of the Tanana River basin in Alaska and Canada, traditionally lived in matrilineal semi-nomadic bands. The Powhatan and other tribes of the Tsenacommacah , also known as the Powhatan Confederacy, practiced
23349-660: 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. Denisovans are known to have lived in Siberia, Tibet, and Laos. The Xiahe mandible
23530-540: The field of zoology , and biology in general, and has also become an area of concern outside the scientific community. A number of organizations, such as the Worldwide Fund for Nature , have been created with the goal of preserving species from extinction. Governments have attempted, through enacting laws, to avoid habitat destruction, agricultural over-harvesting, and pollution . While many human-caused extinctions have been accidental, humans have also engaged in
23711-435: The form of a physical destruction of niche habitats. The widespread destruction of tropical rainforests and replacement with open pastureland is widely cited as an example of this; elimination of the dense forest eliminated the infrastructure needed by many species to survive. For example, a fern that depends on dense shade for protection from direct sunlight can no longer survive without forest to shelter it. Another example
23892-580: The habitat retreat of taxa approaching extinction. Possible causes of the higher extinction risk in species with more sexual selection shown by the comprehensive fossil studies that rule out such error sources include expensive sexually selected ornaments having negative effects on the ability to survive natural selection , as well as sexual selection removing a diversity of genes that under current ecological conditions are neutral for natural selection but some of which may be important for surviving climate change. There have been at least five mass extinctions in
24073-676: The heaviest losses include the Cape Floristic Region and the Caribbean Basin . These areas might see a doubling of present carbon dioxide levels and rising temperatures that could eliminate 56,000 plant and 3,700 animal species. Climate change has also been found to be a factor in habitat loss and desertification . Studies of fossils following species from the time they evolved to their extinction show that species with high sexual dimorphism , especially characteristics in males that are used to compete for mating, are at
24254-500: The highlands having variants for early brain development and those living in the lowlands having variants for the immune system. Based on the high percentages of Denisovan DNA in modern Papuans and Australians, Denisovans may have crossed the Wallace Line into these regions (with little back-migration west), the second known human species to do so, along with earlier Homo floresiensis . By this logic, they may have also entered
24435-447: The history of life on earth, and four in the last 350 million years in which many species have disappeared in a relatively short period of geological time. A massive eruptive event that released large quantities of tephra particles into the atmosphere is considered to be one likely cause of the " Permian–Triassic extinction event " about 250 million years ago, which is estimated to have killed 90% of species then existing. There
24616-475: The human era since the Late Pleistocene would require 5 to 7 million years to recover. According to the 2019 Global Assessment Report on Biodiversity and Ecosystem Services by IPBES , the biomass of wild mammals has fallen by 82%, natural ecosystems have lost about half their area and a million species are at risk of extinction—all largely as a result of human actions. Twenty-five percent of plant and animal species are threatened with extinction. In
24797-479: The immune system of present-day Papuans and potentially favoured "variants to immune-related phenotypes" and "adaptation to the local environment". In December 2023, scientists reported that genes inherited by modern humans from Neanderthals and Denisovans may biologically influence the daily routine of modern humans. Extinct Extinction is the termination of a taxon by the death of its last member . A taxon may become functionally extinct before
24978-431: The introduced ( or hybrid ) species. Endemic populations can face such extinctions when new populations are imported or selectively bred by people, or when habitat modification brings previously isolated species into contact. Extinction is likeliest for rare species coming into contact with more abundant ones; interbreeding can swamp the rarer gene pool and create hybrids, depleting the purebred gene pool (for example,
25159-499: 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 , Croatia, as opposed to archaics related to Siberian Neanderthals and Denisovans. However, about 3.3% of
25340-421: The jungles of Southeast Asia. The Tam Ngu Hao 2 site might have been a closed forest environment. Little is known of the precise anatomical features of the Denisovans since the only physical remains discovered so far are a finger bone, four teeth, long bone fragments, a partial jawbone, a parietal bone skull fragment, and a rib bone. The finger bone is within the modern human range of variation for women, which
25521-458: The land that is present-day New Jersey was overseen by clans of the Lenape , who farmed, fished, and hunted upon it. The pattern of their culture was that of a matrilineal agricultural and mobile hunting society that was sustained with fixed, but not permanent, settlements in their matrilineal clan territories. Leadership by men was inherited through the maternal line, and the women elders held
25702-457: The lineage land farmed by its members, functions together in the veneration of its ancestors, supervises marriages of its members, and settles internal disputes among its members. The political units above are likewise grouped into eight larger groups called abusua (similar to clans ), named Aduana, Agona, Asakyiri, Asenie, Asona, Bretuo, Ekuona and Oyoko. The members of each abusua are united by their belief that they are all descended from
25883-488: The main drivers of the modern extinction crisis. In January 2020, the UN's Convention on Biological Diversity drafted a plan to mitigate the contemporary extinction crisis by establishing a deadline of 2030 to protect 30% of the Earth's land and oceans and reduce pollution by 50%, with the goal of allowing for the restoration of ecosystems by 2050. The 2020 United Nations ' Global Biodiversity Outlook report stated that of
26064-454: 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 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 at individual genetic loci associated with facial structure. This analysis suggested that Denisovans, much like Neanderthals, had
26245-421: The modern understanding of extinction as the end of a species was incompatible with the prevailing worldview. Prior to the 19th century, much of Western society adhered to the belief that the world was created by God and as such was complete and perfect. This concept reached its heyday in the 1700s with the peak popularity of a theological concept called the great chain of being , in which all life on earth, from
26426-473: The more familiar patrilineal surnames transmitted from father to son, the pattern most common among family names today. For clarity and for brevity, the scientific terms patrilineal surname and matrilineal surname are usually abbreviated as patriname and matriname . There appears to be some evidence for the presence of matrilineality in Pre-Islamic Arabia , in a very limited number of
26607-434: The mud, or dug their finger into the toe prints. The footprints average 192.3 mm (7.57 in) 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 161.1 mm (6.34 in), which roughly equates with
26788-490: The name of a species or other taxon normally indicates its status as extinct. Examples of species and subspecies that are extinct include: A species is extinct when the last existing member dies. Extinction therefore becomes a certainty when there are no surviving individuals that can reproduce and create a new generation. A species may become functionally extinct when only a handful of individuals survive, which cannot reproduce due to poor health, age, sparse distribution over
26969-469: The natural course of events, species become extinct for a number of reasons, including but not limited to: extinction of a necessary host, prey or pollinator, interspecific competition , inability to deal with evolving diseases and changing environmental conditions (particularly sudden changes) which can act to introduce novel predators, or to remove prey. Recently in geological time, humans have become an additional cause of extinction of some species, either as
27150-410: The newly emerging school of uniformitarianism . Jean-Baptiste Lamarck , a gradualist and colleague of Cuvier, saw the fossils of different life forms as evidence of the mutable character of species. While Lamarck did not deny the possibility of extinction, he believed that it was exceptional and rare and that most of the change in species over time was due to gradual change. Unlike Cuvier, Lamarck
27331-505: 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 humans . 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
27512-426: The oldest known examples of rock art . 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
27693-399: The original population, thereby increasing the chance of extinction. Habitat degradation is currently the main anthropogenic cause of species extinctions. The main cause of habitat degradation worldwide is agriculture, with urban sprawl , logging, mining, and some fishing practices close behind. The degradation of a species' habitat may alter the fitness landscape to such an extent that
27874-525: The population ancestral to both New Guineans and Oceanians. Such a late date for the New Guinean group could indicate Denisovan survival as late as 14,500 years ago, which would make them the latest surviving archaic human species. 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
28055-475: The power to remove leaders of whom they disapproved. Villages were established and relocated as the clans farmed new sections of the land when soil fertility lessened and when they moved among their fishing and hunting grounds by seasons. The area was claimed as a part of the Dutch New Netherland province dating from 1614, where active trading in furs took advantage of the natural pass west, but
28236-702: The process of speciation —where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche —and species become extinct when they are no longer able to survive in changing conditions or against superior competition . The relationship between animals and their ecological niches has been firmly established. A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils , survive with little to no morphological change for hundreds of millions of years. Mass extinctions are relatively rare events; however, isolated extinctions of species and clades are quite common, and are
28417-684: 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 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
28598-410: The relative importance of genetic factors compared to environmental ones as the causes of extinction has been compared to the debate on nature and nurture . The question of whether more extinctions in the fossil record have been caused by evolution or by competition or by predation or by disease or by catastrophe is a subject of discussion; Mark Newman, the author of Modeling Extinction , argues for
28779-414: The same ancient ancestress. Marriage between members of the same abusua is forbidden. One inherits or is a lifelong member of the lineage, the political unit, and the abusua of one's mother, regardless of one's gender and/or marriage. Note that members and their spouses thus belong to different abusuas , mother and children living and working in one household and their husband/father living and working in
28960-467: The same population. The genetic diversity 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 habitation, continually swung from
29141-460: The species is no longer able to survive and becomes extinct. This may occur by direct effects, such as the environment becoming toxic , or indirectly, by limiting a species' ability to compete effectively for diminished resources or against new competitor species. Habitat destruction, particularly the removal of vegetation that stabilizes soil, enhances erosion and diminishes nutrient availability in terrestrial ecosystems. This degradation can lead to
29322-459: The specimen indicated it was more than 160,000 years old. The identity of this population was later confirmed through study of 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. In 2018, a team of Laotian, French, and American anthropologists, who had been excavating caves in the Laotian jungle of
29503-651: The spur to masculine superiority" and, within that, as that women were central to institutions of clan and household and predominated "within the economic and social systems (in contrast to male predominance within the political and ceremonial systems)", the Clan Mother , for example, being empowered to overturn land distribution by men if she felt it was unfair, since there was no "countervailing ... strongly centralized, male-centered political structure". The Iroquois Confederacy or League , combining five to six Native American Haudenosaunee nations or tribes before
29684-430: The sudden introduction of human beings to environments full of animals that had never seen them before and were therefore completely unadapted to their predation techniques. Coextinction refers to the loss of a species due to the extinction of another; for example, the extinction of parasitic insects following the loss of their hosts. Coextinction can also occur when a species loses its pollinator , or to predators in
29865-486: The time hominins spread out across Europe. H. heidelbergensis 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
30046-412: The tiniest microorganism to God, is linked in a continuous chain. The extinction of a species was impossible under this model, as it would create gaps or missing links in the chain and destroy the natural order. Thomas Jefferson was a firm supporter of the great chain of being and an opponent of extinction, famously denying the extinction of the woolly mammoth on the grounds that nature never allows
30227-448: The total extinction of the dodo and the extirpation of indigenous horses to the British Isles. He similarly argued against mass extinctions , believing that any extinction must be a gradual process. Lyell also showed that Cuvier's original interpretation of the Parisian strata was incorrect. Instead of the catastrophic floods inferred by Cuvier, Lyell demonstrated that patterns of saltwater and freshwater deposits , like those seen in
30408-416: The traditional culture of the Guna people of Panama and Colombia, families are matrilinear and matrilocal, with the groom moving to become part of the bride's family. The groom also takes the last name of the bride. The Hopi (in what is now the Hopi Reservation in northeastern Arizona ), according to Alice Schlegel , had as its "gender ideology ... one of female superiority, and it operated within
30589-475: The universality of matrilocality or patrilocality , pointing out that hunter-gatherer societies have a flexible philopatry or practice multilocality, which in turn leads to a more egalitarian society, since both men and women have the right to choose with whom to live. According to some data, pastoralists and farmers strongly gravitate towards patrilocality, so patrilocality is a common phenomenon among non-Pygmies. But among some hunter-gatherers, patrilocality
30770-530: The wider scientific community of his theory. Cuvier was a well-regarded geologist, lauded for his ability to reconstruct the anatomy of an unknown species from a few fragments of bone. His primary evidence for extinction came from mammoth skulls found in the Paris basin . Cuvier recognized them as distinct from any known living species of elephant, and argued that it was highly unlikely such an enormous animal would go undiscovered. In 1812, Cuvier, along with Alexandre Brongniart and Geoffroy Saint-Hilaire , mapped
30951-518: The women, whereas personal property is owned and inherited regardless of gender. In contrast to most other Muslim cultural groups, men wear veils but women do not. This custom is discussed in more detail in the Tuareg article's clothing section , which mentions it may be the protection needed against the blowing sand while traversing the Sahara desert . The Bororo people of Brazil and Bolivia live in matrilineal clans, with husbands moving to live with their wives' extended families. The clan system of
31132-434: Was a single specimen from the Baishiya Karst Cave on the Tibetan Plateau , and Cobra Cave in the Annamite Mountains of Laos. DNA evidence suggests they had dark skin, eyes, and hair, and had a Neanderthal-like build and facial features. However, they had larger molars which are reminiscent of Middle to Late Pleistocene archaic humans and australopithecines . Denisovans apparently interbred with modern humans, with
31313-567: Was also evidence of stone artefacts in each layer excavated. Some older findings may or may not belong to the Denisovan line, but Asia is not well mapped in regards to human evolution . Such findings include the Dali skull , the Xujiayao hominin, Maba Man , the Jinniushan hominin, and the Narmada Human . The Xiahe mandible shows morphological similarities to some later East Asian fossils such as Penghu 1 , but also to Chinese H. erectus . In 2021, Chinese palaeoanthropologist Qiang Ji suggested his newly erected species, H. longi , may represent
31494-400: Was cut into two, and the initial DNA sequencing of one fragment was later independently confirmed by sequencing the mtDNA from the second. Denisova Cave contained the only known examples of Denisovans until 2019, when a research group led by Fahu Chen , Dongju Zhang , and Jean-Jacques Hublin described a partial mandible discovered in 1980 by a Buddhist monk in the Baishiya Karst Cave on
31675-425: Was difficult to disprove. When parts of the world had not been thoroughly examined and charted, scientists could not rule out that animals found only in the fossil record were not simply "hiding" in unexplored regions of the Earth. Georges Cuvier is credited with establishing the modern conception of extinction in a 1796 lecture to the French Institute , though he would spend most of his career trying to convince
31856-466: Was inconclusive for this specimen, but the team found it anatomically comparable with the Xiahe mandible, and so tentatively categorized it as a Denisovan, although they could not rule out it being Neanderthal. The tooth probably dates to 164,000 to 131,000 years ago. In 2024 a ZooMS analysis of more than 2,500 bones found in Baishiya Karst Cave revealed a further bone fragment; a rib bone dating from between 48,000 BP and 32,000 BP. The conclusion of
32037-430: Was not until 1982, when David Raup and Jack Sepkoski published their seminal paper on mass extinctions, that Cuvier was vindicated and catastrophic extinction was accepted as an important mechanism . The current understanding of extinction is a synthesis of the cataclysmic extinction events proposed by Cuvier, and the background extinction events proposed by Lyell and Darwin. Extinction is an important research topic in
32218-485: Was originally named X-woman because matrilineal 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 Neanderthals . In 2019, Greek archaeologist Katerina Douka and colleagues radiocarbon dated 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
32399-571: Was skeptical that catastrophic events of a scale large enough to cause total extinction were possible. In his geological history of the earth titled Hydrogeologie, Lamarck instead argued that the surface of the earth was shaped by gradual erosion and deposition by water, and that species changed over time in response to the changing environment. Charles Lyell , a noted geologist and founder of uniformitarianism , believed that past processes should be understood using present day processes. Like Lamarck, Lyell acknowledged that extinction could occur, noting
32580-401: Was taken up by Friedrich Engels in The Origin of the Family, Private Property and the State . The Morgan-Engels thesis that humanity's earliest domestic institution was not the family but the matrilineal clan soon became incorporated into communist orthodoxy . In reaction, most 20th century social anthropologists considered the theory of matrilineal priority untenable, although during
32761-480: Was – and, in the following list, still is if shown in italics – inherited matrilineally. Examples include the Cherokee , Choctaw , Gitksan , Haida , Hopi , Iroquois , Lenape , Navajo and Tlingit of North America ; the Cabécar and Bribri of Costa Rica; the Naso and Kuna people of Panama; the Kogi , Wayuu and Carib of South America; the Minangkabau people of West Sumatra , Indonesia and Negeri Sembilan , Malaysia ;
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