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Haplogroup L (mtDNA)
In human mitochondrial genetics, L is the mitochondrial DNA macro-haplogroup that is at the root of the anatomically modern human (''Homo sapiens'') mtDNA phylogenetic tree. As such, it represents the most ancestral mitochondrial lineage of all currently living modern humans, also dubbed "Mitochondrial Eve". Its two sub-clades are L1-6 and L0. The split occurred during the Penultimate Glacial Period; L1-6 is estimated to have formed ca. 170 kya, and L0 ca. 150 kya. The formation of L0 is associated with the peopling of Southern Africa by populations ancestral to the Khoisan, ca. 140 kya, at the onset of the Eemian interglacial. L is further subdivided into L1-6 and L1, dated ca. 150 kya and 130 kya, respectively. Haplogroups L5 (120 kya), L2 and L6 (90 kya), L4 (80 kya) and L3 (70 kya). Origin The outgroup for mtDNA phylogeny of modern humans is the mtDNA of archaic humans, specifically Neanderthals and Denisovans. The split of the modern human lineage from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
95% CI
In frequentist statistics, a confidence interval (CI) is a range of estimates for an unknown parameter. A confidence interval is computed at a designated ''confidence level''; the 95% confidence level is most common, but other levels, such as 90% or 99%, are sometimes used. The confidence level represents the long-run proportion of corresponding CIs that contain the true value of the parameter. For example, out of all intervals computed at the 95% level, 95% of them should contain the parameter's true value. Factors affecting the width of the CI include the sample size, the variability in the sample, and the confidence level. All else being the same, a larger sample produces a narrower confidence interval, greater variability in the sample produces a wider confidence interval, and a higher confidence level produces a wider confidence interval. Definition Let be a random sample from a probability distribution with statistical parameter , which is a quantity to be estimated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup L5 (mtDNA)
Haplogroup L5 is a human mitochondrial DNA (mtDNA) clade. It was previously known as L1e. Distribution L5 is a small haplogroup centered in East Africa. The highest frequency is in Mbuti Pygmies from Eastern Central Africa at 15%. It is present in relatively small frequencies in Tanzania ( Sandawe and others), Kenya, Chad, Ethiopia, Sudan, Nubia, EgyptSample UPE52 is subclade L5a. and Saudi Arabia. Haplogroup L5 has been observed among specimens at the island cemetery in Kulubnarti, Sudan Sudan ( or ; ar, السودان, as-Sūdān, officially the Republic of the Sudan ( ar, جمهورية السودان, link=no, Jumhūriyyat as-Sūdān), is a country in Northeast Africa. It shares borders with the Central African Republic t ..., which date from the Early Christian period (AD 550–800). Subclades Tree This phylogenetic tree of haplogroup L5 subclades is based on the paper by Mannis van Oven and Manfred Kayser ''Updated comprehensive phylogenetic tree of global human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup L7 (mtDNA)
Haplogroup L4 is a human mitochondrial DNA (mtDNA) haplogroup. It is a small maternal clade primarily restricted to Africa. L4 is important in East Africa. The highest frequencies are in Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ... among the Hadza at 60-83% and Sandawe at 48%. It has two branches, L4a and L4b. Subgroup L4a was formerly called L7 and considered a separate subclade of L3'4'7. It has been recognized as a subclade of L4, with L3 as its outgroup by Behar et al. (2008). The parent clade L3'4 is to have emerged at 106–66 kya. L4 is not much later than this, estimated at 87 kya by Fernandes et al. (2015).Fernandes V, Triska P, Pereira JB, Alshamali F, Rito T, Machado A, et al. (2015) Genetic Stratigraphy of Key Demographic Events in Arabia. P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastern Africa
East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historical Omani Empire and colonial territories of the British East Africa Protectorate and German East Africa, the term ''East Africa'' is often (especially in the English language) used to specifically refer to the area now comprising the three countries of Kenya, Tanzania, and Uganda. However, this has never been the convention in many other languages, where the term generally had a wider, strictly geographic context and therefore typically included Djibouti, Eritrea, Ethiopia, and Somalia.Somaliland is not included in the United Nations geoscheme, as it is internationally recognized as a part of Somalia. *Tanzania, Kenya, Uganda, Rwanda, Burundi, Democratic Republic of Congo and South Sudan are members of the East African Community. The firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Most Recent Common Ancestor
In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of organisms is the most recent individual from which all the organisms of the set are descended. The term is also used in reference to the ancestry of groups of genes (haplotypes) rather than organisms. The MRCA of a set of individuals can sometimes be determined by referring to an established pedigree. However, in general, it is impossible to identify the exact MRCA of a large set of individuals, but an estimate of the time at which the MRCA lived can often be given. Such ''time to most recent common ancestor'' (''TMRCA'') estimates can be given based on DNA test results and established mutation rates as practiced in genetic genealogy, or by reference to a non-genetic, mathematical model or computer simulation. In organisms using sexual reproduction, the ''matrilineal MRCA'' and ''patrilineal MRCA'' are the MRCAs of a given population ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jebel Irhoud
Jebel Irhoud or Adrar n Ighoud ( zgh, ⴰⴷⵔⴰⵔ ⵏ ⵉⵖⵓⴷ, Adrar n Iɣud; ar, جبل إيغود, žbəl iġud), is an archaeological site located just north of the locality known as Tlet Ighoud, approximately south-east of the city of Safi in Morocco. It is noted for the hominin fossils that have been found there since the discovery of the site in 1960. Originally thought to be Neanderthals, the specimens have since been assigned to ''Homo sapiens'' and, as reported in 2017, have been dated to roughly 300,000 years ago ( for the Irhoud 3 mandible, based on other fossils and the flint artefacts found nearby). * *"Here we report the ages, determined by thermoluminescence dating, of fire-heated flint artefacts obtained from new excavations at the Middle Stone Age site of Jebel Irhoud, Morocco, which are directly associated with newly discovered remains of H. sapiens8. A weighted average age places these Middle Stone Age artefacts and fossils at 315 ± 34 thousand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interbreeding Between Archaic And Modern Humans
There is evidence for interbreeding between archaic and modern humans during the Middle Paleolithic and early Upper Paleolithic. The interbreeding happened in several independent events that included Neanderthals and Denisovans, as well as several unidentified hominins. In Eurasia, interbreeding between Neanderthals and Denisovans with modern humans took place several times. The introgression events into modern humans are estimated to have happened about 47,000–65,000 years ago with Neanderthals and about 44,000–54,000 years ago with Denisovans. Neanderthal-derived DNA has been found in the genomes of most or possibly all contemporary populations, varying noticeably by region. It accounts for 1–4% of modern genomes for people outside Sub-Saharan Africa, although estimates vary, and either none or possibly up to 0.3% — according to recent research — for those in Africa. It is highest in East Asians, intermediate in Europeans, and lower in Southeast Asians. According to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Y-chromosome DNA Haplogroup
In human genetics, a human Y-chromosome DNA haplogroup is a haplogroup defined by mutations in the non- recombining portions of DNA from the male-specific Y chromosome (called Y-DNA). Many people within a haplogroup share similar numbers of short tandem repeats (STRs) and types of mutations called single-nucleotide polymorphisms (SNPs). The human Y-chromosome accumulates roughly two mutations per generation. "one mutation in every 30 million base pairs" Y-DNA haplogroups represent major branches of the Y-chromosome phylogenetic tree that share hundreds or even thousands of mutations unique to each haplogroup. The Y-chromosomal most recent common ancestor (Y-MRCA, informally known as Y-chromosomal Adam) is the most recent common ancestor (MRCA) from whom all currently living humans are descended patrilineally. Y-chromosomal Adam is estimated to have lived roughly 236,000 years ago in Africa. By examining other bottlenecks most Eurasian men (men from populations outside of Afri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denisovans
The Denisovans or Denisova hominins ) are an extinct species or subspecies of archaic human that ranged across Asia during the Lower and Middle Paleolithic. Denisovans are known from few physical remains and 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 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 was a single specimen from the Baishiya Karst Cave on the Tibetan Plateau. DNA evidence suggests they had dark skin, eyes, and hair, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neanderthals
Neanderthals (, also ''Homo neanderthalensis'' and erroneously ''Homo sapiens neanderthalensis''), also written as Neandertals, are an Extinction, extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ago. While the "causes of Neanderthal disappearance about 40,000 years ago remain highly contested," demographic factors such as small population size, inbreeding and genetic drift, are considered probable factors. Other scholars have proposed competitive replacement, assimilation into the modern human genome (bred into extinction), great climate change, climatic change, disease, or a combination of these factors. It is unclear when the line of Neanderthals split from that of Early modern human, modern humans; studies have produced various intervals ranging from 315,000 to more than 800,000 years ago. The date of divergence of Neanderthals from their ancestor ''Homo heidelbergensis, H. heidelbergensis'' is also unclear. The oldest potential ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaic Humans
A number of varieties of ''Homo'' are grouped into the broad category of archaic humans in the period that precedes and is contemporary to the emergence of the earliest early modern humans (''Homo sapiens'') around 300 ka. Omo-Kibish I (Omo I) from southern Ethiopia ( 195 or 233 ka), the remains from Jebel Irhoud in Morocco (about 315 ka) and Florisbad in South Africa (259 ka) are among the earliest remains of ''Homo sapiens''. The term typically includes ''Homo neanderthalensis'' (430 ± 25 ka), Denisovans, ''Homo rhodesiensis'' (300–125 ka), ''Homo heidelbergensis'' (600–200 ka), ''Homo naledi'', ''Homo ergaster'', ''Homo antecessor'', and '' Homo habilis''. There is no universal consensus on this terminology, and varieties of "archaic humans" are included under the binomial name of either ''Homo sapiens'' or ''Homo erectus'' by some authors. Archaic humans had a brain size averaging 1,200 to 1,400 cubic centimeters, which overlaps with the range of modern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup L3 (mtDNA)
Haplogroup L3 is a human mitochondrial DNA (mtDNA) haplogroup. The clade has played a pivotal role in the early dispersal of anatomically modern humans. It is strongly associated with the out-of-Africa migration of modern humans of about 70–50,000 years ago. It is inherited by all modern non-African populations, as well as by some populations in Africa. Origin Haplogroup L3 arose close to 70,000 years ago, near the time of the recent out-of-Africa event. This dispersal originated in East Africa and expanded to West Asia, and further to South and Southeast Asia in the course of a few millennia, and some research suggests that L3 participated in this migration out of Africa. A 2007 estimate for the age of L3 suggested a range of 104–84,000 years ago. More recent analyses, including Soares et al. (2012) arrive at a more recent date, of roughly 70–60,000 years ago. Soares et al. also suggest that L3 most likely expanded from East Africa into Eurasia sometime around 65–55, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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