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494 result(s) for "Hominidae - classification"
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Neandertal and Denisovan DNA from Pleistocene sediments
Although a rich record of Pleistocene human-associated archaeological assemblages exists, the scarcity of hominin fossils often impedes the understanding of which hominins occupied a site. Using targeted enrichment of mitochondrial DNA, we show that cave sediments represent a rich source of ancient mammalian DNA that often includes traces of hominin DNA, even at sites and in layers where no hominin remains have been discovered. By automation-assisted screening of numerous sediment samples, we detected Neandertal DNA in eight archaeological layers from four caves in Eurasia. In Denisova Cave, we retrieved Denisovan DNA in a Middle Pleistocene layer near the bottom of the stratigraphy. Our work opens the possibility of detecting the presence of hominin groups at sites and in areas where no skeletal remains are found.
The evolution and changing ecology of the African hominid oral microbiome
The oral microbiome plays key roles in human biology, health, and disease, but little is known about the global diversity, variation, or evolution of this microbial community. To better understand the evolution and changing ecology of the human oral microbiome, we analyzed 124 dental biofilm metagenomes from humans, including Neanderthals and Late Pleistocene to present-day modern humans, chimpanzees, and gorillas, as well as New World howler monkeys for comparison. We find that a core microbiome of primarily biofilm structural taxa has been maintained throughout African hominid evolution, and these microbial groups are also shared with howler monkeys, suggesting that they have been important oral members since before the catarrhine–platyrrhine split ca. 40 Mya. However, community structure and individual microbial phylogenies do not closely reflect host relationships, and the dental biofilms of Homo and chimpanzees are distinguished by major taxonomic and functional differences. Reconstructing oral metagenomes from up to 100 thousand years ago, we show that the microbial profiles of both Neanderthals and modern humans are highly similar, sharing functional adaptations in nutrient metabolism. These include an apparent Homo-specific acquisition of salivary amylase-binding capability by oral streptococci, suggesting microbial coadaptation with host diet. We additionally find evidence of shared genetic diversity in the oral bacteria of Neanderthal and Upper Paleolithic modern humans that is not observed in later modern human populations. Differences in the oral microbiomes of African hominids provide insights into human evolution, the ancestral state of the human microbiome, and a temporal framework for understanding microbial health and disease.
Complete sequencing of ape genomes
The most dynamic and repetitive regions of great ape genomes have traditionally been excluded from comparative studies 1 , 2 – 3 . Consequently, our understanding of the evolution of our species is incomplete. Here we present haplotype-resolved reference genomes and comparative analyses of six ape species: chimpanzee, bonobo, gorilla, Bornean orangutan, Sumatran orangutan and siamang. We achieve chromosome-level contiguity with substantial sequence accuracy (<1 error in 2.7 megabases) and completely sequence 215 gapless chromosomes telomere-to-telomere. We resolve challenging regions, such as the major histocompatibility complex and immunoglobulin loci, to provide in-depth evolutionary insights. Comparative analyses enabled investigations of the evolution and diversity of regions previously uncharacterized or incompletely studied without bias from mapping to the human reference genome. Such regions include newly minted gene families in lineage-specific segmental duplications, centromeric DNA, acrocentric chromosomes and subterminal heterochromatin. This resource serves as a comprehensive baseline for future evolutionary studies of humans and our closest living ape relatives. Complete sequences of chromosomes telomere-to-telomere from chimpanzee, bonobo, gorilla, Bornean orangutan, Sumatran orangutan and siamang provide a comprehensive and valuable resource for future evolutionary comparisons.
New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens
New human fossils from Jebel Irhoud (Morocco) document the earliest evolutionary stage of Homo sapiens and display modern conditions of the face and mandible combined with more primative features of the neurocranium. Early dawn for Homo sapiens The exact place and time that our species emerged remains obscure because the fossil record is limited and the chronological age of many key specimens remains uncertain. Previous fossil evidence has placed the emergence of modern human biology in eastern Africa around 200,000 years ago. In this issue of Nature , Jean-Jaques Hublin and colleagues report new human fossils from Jebel Irhoud, Morocco; their work is accompanied by a separate report on the dating of the fossils by Shannon McPherron and colleagues. Together they report remains dating back 300,000–350,000 years. They identify numerous features, including a facial, mandibular and dental morphology, that align the material with early or recent modern humans. They also identified more primitive neurocranial and endocranial morphology. Collectively, the researchers believe that this mosaic of features displayed by the Jebel Irhoud hominins assigns them to the earliest evolutionary phase of Homo sapiens . Both papers suggest that the evolutionary processes behind the emergence of modern humans were not confined to sub-Saharan Africa. Fossil evidence points to an African origin of Homo sapiens from a group called either H. heidelbergensis or H. rhodesiensis . However, the exact place and time of emergence of H. sapiens remain obscure because the fossil record is scarce and the chronological age of many key specimens remains uncertain. In particular, it is unclear whether the present day ‘modern’ morphology rapidly emerged approximately 200 thousand years ago (ka) among earlier representatives of H. sapiens 1 or evolved gradually over the last 400 thousand years 2 . Here we report newly discovered human fossils from Jebel Irhoud, Morocco, and interpret the affinities of the hominins from this site with other archaic and recent human groups. We identified a mosaic of features including facial, mandibular and dental morphology that aligns the Jebel Irhoud material with early or recent anatomically modern humans and more primitive neurocranial and endocranial morphology. In combination with an age of 315 ± 34 thousand years (as determined by thermoluminescence dating) 3 , this evidence makes Jebel Irhoud the oldest and richest African Middle Stone Age hominin site that documents early stages of the H. sapiens clade in which key features of modern morphology were established. Furthermore, it shows that the evolutionary processes behind the emergence of H. sapiens involved the whole African continent.
A late Middle Pleistocene Denisovan mandible from the Tibetan Plateau
Denisovans are members of a hominin group who are currently only known directly from fragmentary fossils, the genomes of which have been studied from a single site, Denisova Cave 1 – 3 in Siberia. They are also known indirectly from their genetic legacy through gene flow into several low-altitude East Asian populations 4 , 5 and high-altitude modern Tibetans 6 . The lack of morphologically informative Denisovan fossils hinders our ability to connect geographically and temporally dispersed fossil hominins from Asia and to understand in a coherent manner their relation to recent Asian populations. This includes understanding the genetic adaptation of humans to the high-altitude Tibetan Plateau 7 , 8 , which was inherited from the Denisovans. Here we report a Denisovan mandible, identified by ancient protein analysis 9 , 10 , found on the Tibetan Plateau in Baishiya Karst Cave, Xiahe, Gansu, China. We determine the mandible to be at least 160 thousand years old through U-series dating of an adhering carbonate matrix. The Xiahe specimen provides direct evidence of the Denisovans outside the Altai Mountains and its analysis unique insights into Denisovan mandibular and dental morphology. Our results indicate that archaic hominins occupied the Tibetan Plateau in the Middle Pleistocene epoch and successfully adapted to high-altitude hypoxic environments long before the regional arrival of modern Homo sapiens . Fossil evidence indicates that Denisovans occupied the Tibetan Plateau in the Middle Pleistocene epoch and successfully adapted to this high-altitude hypoxic environments long before the regional arrival of modern Homo sapiens .
Nuclear DNA sequences from the Middle Pleistocene Sima de los Huesos hominins
Nuclear DNA sequences from Middle Pleistocene Sima de los Huesos hominins show they were more closely related to Neanderthals than to Denisovans, and indicate a population divergence between Neanderthals and Denisovans that predates 430,000 years ago. Neanderthal-like hominins in Middle Pleistocene Spain This genomic analysis of Middle Pleistocene hominins from Sima de los Huesos in the Sierra de Atapuerca in Spain shows that they were more closely related to Neanderthals than to Denisovans, and indicates a divergence between Neanderthals and Denisovans that predates 430,000 years ago. A previous report based on analyses of mitochondrial genomes from these specimens had suggested close relationship to Denisovans, which was in contrast to other archaeological evidence including morphological features shared with Late Pleistocene Neanderthals. A unique assemblage of 28 hominin individuals, found in Sima de los Huesos in the Sierra de Atapuerca in Spain, has recently been dated to approximately 430,000 years ago 1 . An interesting question is how these Middle Pleistocene hominins were related to those who lived in the Late Pleistocene epoch, in particular to Neanderthals in western Eurasia and to Denisovans, a sister group of Neanderthals so far known only from southern Siberia. While the Sima de los Huesos hominins share some derived morphological features with Neanderthals, the mitochondrial genome retrieved from one individual from Sima de los Huesos is more closely related to the mitochondrial DNA of Denisovans than to that of Neanderthals 2 . However, since the mitochondrial DNA does not reveal the full picture of relationships among populations, we have investigated DNA preservation in several individuals found at Sima de los Huesos. Here we recover nuclear DNA sequences from two specimens, which show that the Sima de los Huesos hominins were related to Neanderthals rather than to Denisovans, indicating that the population divergence between Neanderthals and Denisovans predates 430,000 years ago. A mitochondrial DNA recovered from one of the specimens shares the previously described relationship to Denisovan mitochondrial DNAs, suggesting, among other possibilities, that the mitochondrial DNA gene pool of Neanderthals turned over later in their history.
Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa
Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa. Modern humans, or Homo sapiens, are now the only living species in their genus. But as recently as 100,000 years ago, there were several other species that belonged to the genus Homo. Together with modern humans, these extinct human species, our immediate ancestors and their close relatives, are collectively referred to as ‘hominins’. Now Berger et al. report the recent discovery of an extinct species from the genus Homo that was unearthed from deep underground in what has been named the Dinaledi Chamber, in the Rising Star cave system in South Africa. The species was named Homo naledi; ‘naledi’ means ‘star’ in Sotho (also called Sesotho), which is one of the languages spoken in South Africa. The unearthed fossils were from at least 15 individuals and include multiple examples of most of the bones in the skeleton. Based on this wide range of specimens from a single site, Berger et al. describe Homo naledi as being similar in size and weight to a small modern human, with human-like hands and feet. Furthermore, while the skull had several unique features, it had a small braincase that was most similar in size to other early hominin species that lived between four million and two million years ago. Homo naledi's ribcage, shoulders and pelvis also more closely resembled those of earlier hominin species than those of modern humans. The Homo naledi fossils are the largest collection of a single species of hominin that has been discovered in Africa so far and, in a related study, Dirks et al. describe the setting and context for these fossils. However, since the age of the fossils remains unclear, one of the next challenges will be to date the remains to provide more information about the early evolution of humans and their close relatives.
Contemporaneity of Australopithecus, Paranthropus, and early Homo erectus in South Africa
Fossil hominins from South Africa are enriching the story of early human evolution and dispersal. Herries et al. describe the geological context and dating of the hominin-bearing infilled cave, or palaeocave, at a site called Drimolen in South Africa (see the Perspective by Antón). They focus on the age and context of a recently discovered Homo erectus sensu lato fossil and a Paranthropus robustus fossil, which they dated to ∼2.04 million to 1.95 million years ago. This makes Drimolen one of the best-dated sites in South Africa and establishes these fossils as the oldest definitive specimens of their respective species ever discovered. The age confirms that species of Australopithecus, Paranthropus , and early Homo overlapped in the karst of South Africa ∼2 million years ago. Science , this issue p. eaaw7293 ; see also p. 34 Multiple hominin genera, including the earliest Homo erectus lineage, were present in South Africa 2 million years ago. Understanding the extinction of Australopithecus and origins of Paranthropus and Homo in South Africa has been hampered by the perceived complex geological context of hominin fossils, poor chronological resolution, and a lack of well-preserved early Homo specimens. We describe, date, and contextualize the discovery of two hominin crania from Drimolen Main Quarry in South Africa. At ~2.04 million to 1.95 million years old, DNH 152 represents the earliest definitive occurrence of Paranthropus robustus , and DNH 134 represents the earliest occurrence of a cranium with clear affinities to Homo erectus . These crania also show that Homo , Paranthropus , and Australopithecus were contemporaneous at ~2 million years ago. This high taxonomic diversity is also reflected in non-hominin species and provides evidence of endemic evolution and dispersal during a period of climatic variability.
Great ape genetic diversity and population history
High-coverage sequencing of 79 (wild and captive) individuals representing all six non-human great ape species has identified over 88 million single nucleotide polymorphisms providing insight into ape genetic variation and evolutionary history and enabling comparison with human genetic diversity. Genetic picture of endangered great apes In an effort to provide insights into great ape genetic variation, the authors sequence 79 wild- and captive-born individuals from across all six great ape species and seven subspecies. Their data and analyses shed light on population structure and gene flow, inbreeding, inferred dynamics of effective population sizes and the differences in the rate of gene loss among the great apes. This new catalogue of great ape genome diversity provides a valuable resource for evolutionary and conservation studies. Most great ape genetic variation remains uncharacterized 1 , 2 ; however, its study is critical for understanding population history 3 , 4 , 5 , 6 , recombination 7 , selection 8 and susceptibility to disease 9 , 10 . Here we sequence to high coverage a total of 79 wild- and captive-born individuals representing all six great ape species and seven subspecies and report 88.8 million single nucleotide polymorphisms. Our analysis provides support for genetically distinct populations within each species, signals of gene flow, and the split of common chimpanzees into two distinct groups: Nigeria–Cameroon/western and central/eastern populations. We find extensive inbreeding in almost all wild populations, with eastern gorillas being the most extreme. Inferred effective population sizes have varied radically over time in different lineages and this appears to have a profound effect on the genetic diversity at, or close to, genes in almost all species. We discover and assign 1,982 loss-of-function variants throughout the human and great ape lineages, determining that the rate of gene loss has not been different in the human branch compared to other internal branches in the great ape phylogeny. This comprehensive catalogue of great ape genome diversity provides a framework for understanding evolution and a resource for more effective management of wild and captive great ape populations.
Gibbon genome and the fast karyotype evolution of small apes
Gibbons are small arboreal apes that display an accelerated rate of evolutionary chromosomal rearrangement and occupy a key node in the primate phylogeny between Old World monkeys and great apes. Here we present the assembly and analysis of a northern white-cheeked gibbon ( Nomascus leucogenys ) genome. We describe the propensity for a gibbon-specific retrotransposon (LAVA) to insert into chromosome segregation genes and alter transcription by providing a premature termination site, suggesting a possible molecular mechanism for the genome plasticity of the gibbon lineage. We further show that the gibbon genera ( Nomascus , Hylobates , Hoolock and Symphalangus ) experienced a near-instantaneous radiation ∼5 million years ago, coincident with major geographical changes in southeast Asia that caused cycles of habitat compression and expansion. Finally, we identify signatures of positive selection in genes important for forelimb development ( TBX5 ) and connective tissues ( COL1A1 ) that may have been involved in the adaptation of gibbons to their arboreal habitat. The genome of the gibbon, a tree-dwelling ape from Asia positioned between Old World monkeys and the great apes, is presented, providing insights into the evolutionary history of gibbon species and their accelerated karyotypes, as well as evidence for selection of genes such as those for forelimb development and connective tissue that may be important for locomotion through trees. Gibbon genome reflects the high life The many species of gibbons are small, tree-living apes from Southeast Asia, most of them listed as 'endangered' or 'critically endangered' on the IUCN list. In their presentation of the genome of the northern white-cheeked gibbon ( Nomascus leucogenys ) , Lucia Carbone and colleagues provide intriguing insights into the biology and evolutionary history of a group that straddles the divide between Old World monkeys and the great apes. The authors investigate how a novel gibbon-specific retrotransposon might be the source of gibbons' genome plasticity. Rapid karyotype evolution combined with multiple episodes of climate and environmental change might explain the almost instantaneous divergence of the four gibbon genera. Positive selection on genes involved in forelimb development and connective tissue might have been related to gibbons' unique mode of locomotion in the tropical canopy.