Artículos de revistas: "Beringia"

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Lafontaine, J. D. y D. M. Wood. "A ZOOGEOGRAPHIC ANALYSIS OF THE NOCTUIDAE (LEPIDOPTERA) OF BERINGIA, AND SOME INFERENCES ABOUT PAST BERINGIAN HABITATS". Memoirs of the Entomological Society of Canada 120, S144 (1988): 109–23. http://dx.doi.org/10.4039/entm120144109-1.

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AbstractThe 245 species of Noctuidae known from Beringia, i.e. northwestern North America and northeastern Asia, are arranged in six groups based on their habitat preferences. These groups are analysed in terms of their distribution, endemism within Beringia, and zoogeographic affinities. The fauna associated with taiga, boreomontane forests and southern steppe (prairie) habitats shows only limited evidence of continuous occurrence in Beringia, and limited exchange during the Pleistocene between the Nearctic and Palaearctic. We have concluded therefore that this fauna has entered the Beringian area in Recent times following deglaciation of western and central Canada. In wet and dry tundra habitats, in contrast, there is abundant evidence of trans-Beringian faunal exchange. A high degree of endemism in dry tundra habitats within Beringia today is evidence of long-term stability of this habitat. These patterns, as well as evidence from a limited fossil sample of mid-Wisconsinan age, allow us to speculate on Beringian habitats during Wisconsinan times. We further conclude that the eastern Palaearctic and Beringia was the source area for the fauna that repopulated the Canadian Arctic after deglaciation. By contrast, non-Beringian refugia of the Nearctic have contributed little to the fauna of the Arctic.

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Bernatchez, Louis y Julian J. Dodson. "Phylogenetic Relationships among Palearctic and Nearctic Whitefish (Coregonus sp.) Populations as Revealed by Mitochondrial DNA Variation". Canadian Journal of Fisheries and Aquatic Sciences 51, S1 (19 de diciembre de 1994): 240–51. http://dx.doi.org/10.1139/f94-310.

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We recently documented the existence of two highly distinct mitochondrial DNA (mtDNA) phylogenetic groups of Coregonus sp. in Beringia in the absence of geographic separation. To test whether this resulted from secondary intergradation of two groups that evolved in allopatry in Eurasia and Beringia, mtDNA restriction-fragment-length polymorphisms of 210 whitefish representing 22 populations from Europe and Siberia were compared with mtDNA variation observed among 581 fish from North America. Results confirmed that Beringia represents a zone of secondary contact among endemic whitefish and a group of Eurasian origin. All Beringian populations clustered much more closely to Eurasian populations than other North American ones. We also compared mtDNA variation among Palearctic populations with that observed in North America. European populations clustered into two major mtDNA groups that exhibited a strong geographic pattern of distribution, independent of the morphological variation observed among populations: one dominated all the more northern populations and extended to Alaska–Yukon; the second largely dominated samples from central alpine lakes, and was absent from Beringia. These results suggest that central alpine lakes and northern Europe were postglacially recolonized by two genetically distinct white-fish groups that most likely evolved in allopatry followed by limited intergradation.

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3

Elias, Scott A. "Late Pleistocene Climates of Beringia, Based on Analysis of Fossil Beetles". Quaternary Research 53, n.º 2 (marzo de 2000): 229–35. http://dx.doi.org/10.1006/qres.1999.2093.

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AbstractThirty-one fossil beetle assemblages from central and eastern Beringia (Alaska, the Yukon Territory, and the now-submerged Bering Land Bridge) have yielded seasonal temperature estimates for the interval 43,550–9250 14C yr before present (yr B.P.). Estimates of the mean temperature of the warmest (TMAX) and coldest (TMIN) months were derived by the Mutual Climatic Range method. Assemblages from northern and western sites show a mid-Wisconsin interstadial TMAX warming from 35,000–30,000 yr B.P.; this warming is less pronounced in assemblages for interior regions. There is little or no beetle evidence for the spread of coniferous forest in eastern Beringia during this interstade, except for in parts of the Yukon Territory. During the last glacial maximum TMAX values were depressed by about 2°–2.5°C in Arctic regions of Beringia, and by about 4°C in the interior; TMIN values were about 8°C colder in both regions. TMAX and TMIN values rose rapidly at northern sites after 12,000 yr B.P. Seasonal temperatures peaked at 11,000 yr B.P., just as the Bering Land Bridge was inundated. This was followed by a sharp climatic cooling between 11,000 and 10,000 yr B.P., the equivalent of a Younger Dryas cooling in eastern Beringia.

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4

Fedorov, Vadim B., Emiliano Trucchi, Anna V. Goropashnaya, Eric Waltari, Susan Erin Whidden y Nils Chr Stenseth. "Impact of past climate warming on genomic diversity and demographic history of collared lemmings across the Eurasian Arctic". Proceedings of the National Academy of Sciences 117, n.º 6 (27 de enero de 2020): 3026–33. http://dx.doi.org/10.1073/pnas.1913596117.

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The Arctic climate was warmer than today at the last interglacial and the Holocene thermal optimum. To reveal the impact of past climate-warming events on the demographic history of an Arctic specialist, we examined both mitochondrial and nuclear genomic variation in the collared lemming (Dicrostonyx torquatus, Pallas), a keystone species in tundra communities, across its entire distribution in northern Eurasia. The ancestral phylogenetic position of the West Beringian group and divergence time estimates support the hypothesis of continental range contraction to a single refugial area located in West Beringia during high-magnitude warming of the last interglacial, followed by westward recolonization of northern Eurasia in the last glacial period. The West Beringian group harbors the highest mitogenome diversity and its inferred demography indicates a constantly large effective population size over the Late Pleistocene to Holocene. This suggests that northward forest expansion during recent warming of the Holocene thermal optimum did not affect the gene pool of the collared lemming in West Beringia but reduced genomic diversity and effective population size in all other regions of the Eurasian Arctic. Demographic inference from genomic diversity was corroborated by species distribution modeling showing reduction in species distribution during past climate warming. These conclusions are supported by recent paleoecological evidence suggesting smaller temperature increases and moderate northward forest advances in the extreme northeast of Eurasia during the Late Pleistocene-to-Holocene warming events. This study emphasizes the importance of West Beringia as a potential refugium for cold-adapted Arctic species under ongoing climate warming.

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Kohli, Manpreet, Marie Djernæs, Melissa Sanchez Herrera, Göran Sahlen, Erik Pilgrim, Thomas J. Simonsen, Kent Olsen y Jessica Ware. "Comparative phylogeography uncovers evolutionary past of Holarctic dragonflies". PeerJ 9 (24 de junio de 2021): e11338. http://dx.doi.org/10.7717/peerj.11338.

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Here, we investigate the evolutionary history of five northern dragonfly species to evaluate what role the last glaciation period may have played in their current distributions. We look at the population structure and estimate divergence times for populations of the following species: Aeshna juncea (Linnaeus), Aeshna subarctica Walker, Sympetrum danae (Sulzer), Libellula quadrimaculata Linnaeus and Somatochlora sahlbergi Trybom across their Holarctic range. Our results suggest a common phylogeographic pattern across all species except for S. sahlbergi. First, we find that North American and European populations are genetically distinct and have perhaps been separated for more than 400,000 years. Second, our data suggests that, based on genetics, populations from the Greater Beringian region (Beringia, Japan and China) have haplotypes that cluster with North America or Europe depending on the species rather than having a shared geographic affinity. This is perhaps a result of fluctuating sea levels and ice sheet coverage during the Quaternary period that influenced dispersal routes and refugia. Indeed, glacial Beringia may have been as much a transit zone as a refugia for dragonflies. Somatochlora sahlbergi shows no genetic variation across its range and therefore does not share the geographic patterns found in the other circumboreal dragonflies studied here. Lastly, we discuss the taxonomic status of Sympetrum danae, which our results indicate is a species complex comprising two species, one found in Eurasia through Beringia, and the other in North America east and south of Beringia. Through this study we present a shared history among different species from different families of dragonflies, which are influenced by the climatic fluctuations of the past.

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Byun, Dae Jung. "Archaeological Artifacts from the Stone Age Solve the Mystery of the First Native Americans". Journal of Scientific Exploration 35, n.º 4 (15 de enero de 2022): 729–51. http://dx.doi.org/10.31275/20212139.

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Many scholars have sought to uncover the mysteries relating to the origins of the earliest Native Americans. Among many hypotheses, the Beringian Standstill Hypothesis and the Kelp Highway Hypothesis claim that the first Native Americans stayed in Beringia during the Last Glacial Maximum, before migrating to the New World by boat as the climate warmed. Unfortunately, neither hypothesis was devised with tangible supporting evidence, such as archaeological artifacts; as such, both remain controversial. To address this issue, this paper compares and analyzes the genetic data related to the first Native Americans and the data of six archaeological artifacts from the Stone Age. The results show that both hypotheses are correct, but the first Native Americans stayed in Southern Korea rather than Beringia on their journey to America. Genetic and archaeological data converge to show the first Native Americans came from Southern Korea.

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Robert Macey, J., James A. Schulte, Jared L. Strasburg, Jennifer A. Brisson, Allan Larson, Natalia B. Ananjeva, Yuezhao Wang, James F. Parham y Theodore J. Papenfuss. "Assembly of the eastern North American herpetofauna: new evidence from lizards and frogs". Biology Letters 2, n.º 3 (2 de mayo de 2006): 388–92. http://dx.doi.org/10.1098/rsbl.2006.0473.

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Darwin first recognized the importance of episodic intercontinental dispersal in the establishment of worldwide biotic diversity. Faunal exchange across the Bering Land Bridge is a major example of such dispersal. Here, we demonstrate with mitochondrial DNA evidence that three independent dispersal events from Asia to North America are the source for almost all lizard taxa found in continental eastern North America. Two other dispersal events across Beringia account for observed diversity among North American ranid frogs, one of the most species-rich groups of frogs in eastern North America. The contribution of faunal elements from Asia via dispersal across Beringia is a dominant theme in the historical assembly of the eastern North American herpetofauna.

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8

Maschner, Herbert. "Arctic archaeologies: recent work on Beringia". Antiquity 89, n.º 345 (junio de 2015): 740–42. http://dx.doi.org/10.15184/aqy.2015.45.

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This review considers three books on the archaeology of territories situated around the Bering Sea—a region often referred to as Beringia, adopting the term created for the Late Pleistocene landscape that extended from north-east Asia, across the Bering Land Bridge, to approximately the Yukon Territory of Canada. This region is critical to the archaeology of the Arctic for two fundamental reasons. First, it is the gateway to the Americas, and was certainly the route by which the territory was colonised at the end of the last glaciation. Second, it is the place where the entire Aleut-Eskimo (Unangan, Yupik, Alutiiq, Inupiat and Inuit) phenomenon began, and every coastal culture from the far north Pacific, to Chukotka, to north Alaska, and to arctic Canada and Greenland, has its foundation in the cultural developments that occurred around the Bering Sea.

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9

Bombin, Miguel y Karlis Muehlenbachs. "13C/12C Ratios of Pleistocene Mummified Remains from Beringia". Quaternary Research 23, n.º 1 (enero de 1985): 123–29. http://dx.doi.org/10.1016/0033-5894(85)90076-6.

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During the Quaternary glacial episodes, when sea level was considerably lower, Asia and North America were linked by large extensions of circumarctic land (Beringia), which remained unglaciated. This land mass served not only as a biogeographical bridge for plants, animals, and humans, but also supported a biome very different from present tundra or boreal coniferous forests, which was dominated by steppes and a rich mammalian megafauna. Carbon stable isotope ratios of Beringian late Pleistocene mummified remains of bison, equids, mammoth, caribou, musk-ox, moose, woolly rhino, and other undetermined species, found preserved in permafrost, indicate that these megaherbivores fed exclusively on C3 plants, and that C4 grasses were not differentially ingested by bison, as previously suggested. Paleoclimatic constraints probably prevented the formation of a warm-season (C4) guild during the later part of the growing season in the steppes of Beringia during the last glaciation.

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10

Tomczyk, Przemysław Piotr. "BERINGIA – ZAGINIONY LĄD". Kosmos 68, n.º 1 (16 de abril de 2019): 35–41. http://dx.doi.org/10.36921/kos.2019_2507.

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Podczas plejstoceńskich zlodowaceń wskutek globalnego obniżenia poziomu morza, wyłoniły się obszary dotychczas zajęte przez wody. Regionem takim była m.in. Beringia, pas lądu łączący Azję (Syberia) z Ameryką Północną (Alaska i Jukon).Pomimo położenia w strefie podbiegunowej Beringia w plejstocenie nie była zlodowacona, stanowiła bardzo ważne refugium dla organizmów żywych. Niniejsza praca omawia przyczyny istnienia refugium w tym miejscu oraz charakteryzuje jej przyrodę w ciągu plejstocenu i holocenu.Poza funkcją refugium Beringia odegrała również bardzo ważną rolę jako pomost lądowy między kontynentami i trasa migracji, zarówno dla roślin i zwierząt, jak i ludzi. Z uwagi na obydwie role tego lądu, refugium i trasę migracji, Beringia znacząco wpłynęła na obecny kształt świata.

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Lozhkin, Anatoly V., Patricia Anderson, Wendy R. Eisner y Tatiana B. Solomatkina. "Late glacial and holocene landscapes of central Beringia". Quaternary Research 76, n.º 3 (noviembre de 2011): 383–92. http://dx.doi.org/10.1016/j.yqres.2011.08.003.

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AbstractNew palynological and sedimentological data from St. Lawrence Island present a rare view into late-glacial and Holocene environments of the central Bering Land Bridge. The late glaciation was a time of dynamic landscape changes in south-central Beringia, with active thermokarst processes, including the formation and drainage of thaw lakes. The presence of such a wet, unstable substrate, if widespread, probably would have had an adverse impact on food sources and mobility for many of the large mammal populations. The establishment ofBetulashrub tundra on the island suggests late-glacial summers that were warmer than present, consistent with regional paleoclimatic interpretations. However, the increasing proximity to the Bering Sea, as postglacial sea levels rose, modified the intensity of warming and prevented the establishment of deciduous forest as found in other areas of Beringia at this time. The mid- to late Holocene is marked by more stable land surfaces and development ofSphagnumand Cyperaceae peat deposits. The accumulation of organic deposits, decline of shrubBetula, and decrease in thermokarst disturbance suggest that conditions were cooler than the previous. A recent decline in peat accumulation at the study sites may relate to local geomorphology, but similar decreases have been noted for other arctic regions.

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12

Hoffecker, J. F., S. A. Elias y D. H. O'Rourke. "Out of Beringia?" Science 343, n.º 6174 (27 de febrero de 2014): 979–80. http://dx.doi.org/10.1126/science.1250768.

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Pringle, H. "Welcome to Beringia". Science 343, n.º 6174 (27 de febrero de 2014): 961–63. http://dx.doi.org/10.1126/science.343.6174.961.

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14

Whiteman, C. A. "Paleoecology of Beringia". Quaternary Science Reviews 4, n.º 4 (1985): x—xiii. http://dx.doi.org/10.1016/0277-3791(85)90011-3.

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15

Catling, Paul M. y Bruce A. Bennett. "Discovery of a Possibly Relict Outbreeding Morphotype of Sparrow's-egg Lady's-slipper Orchid, Cypripedium passerinum, in Southwestern Yukon". Canadian Field-Naturalist 121, n.º 3 (1 de julio de 2007): 295. http://dx.doi.org/10.22621/cfn.v121i3.477.

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An outbreeding morphotype of Cypripedium passerinum with separate anthers and stigma was discovered in the Beringian region of southwestern Yukon. The occurrence of this breeding system in Beringia is attributed to the persistent advantage of outbreeding over hundreds of thousands of years in this unglaciated area, whereas the widespread occurrence of exclusively self-pollinating races elsewhere in Canada is attributed to advantages in colonization of recently deglaciated territory which first became available less than 10,000 years ago, and/or to a changing and more forested habitat.

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16

Mikkola, Kauri, Donald Lafontaine y Vladimir Kononenko. "Zoogeography of the Holarctic species of the Noctuidae (Lepidoptera): impoftance of the Beringian refuge". Entomologica Fennica 2, n.º 3 (1 de septiembre de 1991): 157–73. http://dx.doi.org/10.33338/ef.83545.

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As a result of published and unpublished revisionary work, literature compilation and expeditions to the Beringian area, 98 species of the Noctuidae are listed as Holarctic and grouped according to their taxonomic and distributional history. Of the 44 species considered to be "naturally" Holarctic before this sttdy, 27 (61%) are confirmed as Holarctic; 16 species are added on account of range extensions and 29 because of changes in their taxonomic status; 17 taxa are deleted from the Holarctic list. This brings the total of the group to 72 species. Thirteen species are considered to be introduced by man from Europe, a further eight to have been transported by man in the subtropical areas, and five migrant species, three of them of Neotropical origin, may have been assisted by man. The majority of the "naturally" Holarctic species are associated with tundra habitats. The species of dry tundra are frequently endemic to Beringia. In the taiga zone, most Holarctic connections consist of Palaearctic/Nearctic species pairs. The proportion of Holarctic species decreases from 100% in the High Arctic to between 40 and 75% in Beringia and the northern taigazone, and from between 10 and 20% in Newfoundland and Finland to between 2 and 4% in southern Ontario, Central Europe, Spain and Primorye. Excluding the species supposedly introduced or assisted by man, all Holarctic species occur in the wider Beringian area (Pyrrhia exprimens (Wlk.) has been observed only in Kamchatka and Anaplectoides prasina (D. &. S.) near the southern border of the Yukon); 36/72 (50%) of the Holarctic species are circumpolar in distribution. The earlier view about Amphiatlantic distributions in the Lepidoptera is refuted. The origin of the Beringian fauna and the mammoth-steppe idea are discussed.

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Morlan, Richard E. "Current perspectives on the Pleistocene archaeology of eastern Beringia". Quaternary Research 60, n.º 1 (julio de 2003): 123–32. http://dx.doi.org/10.1016/s0033-5894(03)00070-x.

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AbstractMost recent summaries of eastern Beringian (Alaska and Yukon) archaeology present the Nenana complex, beginning 11,500–12,000 14C yr B.P., as the beginning of the regional archaeological record. Either explicitly or tacitly, these summaries dismiss or ignore a body of older putative evidence of human occupation that may span the late Wisconsin stade and even extend into part of the mid-Wisconsin interstade. This paper summarizes the interpretive problems surrounding the older findings, bringing together data that have accumulated over a period of two decades, in the hope that a coherent presentation will encourage more careful appraisals of the materials. The paper concludes with a family of testable hypotheses concerning the beginnings of human occupation in eastern Beringia. The hypothesis that people were present during the mid-Wisconsin interstade has not yet been falsified.

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Alerstam, Thomas, Johan Bäckman, Gudmundur A. Gudmundsson, Anders Hedenström, Sara S. Henningsson, Håkan Karlsson, Mikael Rosén y Roine Strandberg. "A polar system of intercontinental bird migration". Proceedings of the Royal Society B: Biological Sciences 274, n.º 1625 (7 de agosto de 2007): 2523–30. http://dx.doi.org/10.1098/rspb.2007.0633.

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Studies of bird migration in the Beringia region of Alaska and eastern Siberia are of special interest for revealing the importance of bird migration between Eurasia and North America, for evaluating orientation principles used by the birds at polar latitudes and for understanding the evolutionary implications of intercontinental migratory connectivity among birds as well as their parasites. We used tracking radar placed onboard the ice-breaker Oden to register bird migratory flights from 30 July to 19 August 2005 and we encountered extensive bird migration in the whole Beringia range from latitude 64° N in Bering Strait up to latitude 75° N far north of Wrangel Island, with eastward flights making up 79% of all track directions. The results from Beringia were used in combination with radar studies from the Arctic Ocean north of Siberia and in the Beaufort Sea to make a reconstruction of a major Siberian–American bird migration system in a wide Arctic sector between longitudes 110° E and 130° W, spanning one-third of the entire circumpolar circle. This system was estimated to involve more than 2 million birds, mainly shorebirds, terns and skuas, flying across the Arctic Ocean at mean altitudes exceeding 1 km (maximum altitudes 3–5 km). Great circle orientation provided a significantly better fit with observed flight directions at 20 different sites and areas than constant geographical compass orientation. The long flights over the sea spanned 40–80 degrees of longitude, corresponding to distances and durations of 1400–2600 km and 26–48 hours, respectively. The birds continued from this eastward migration system over the Arctic Ocean into several different flyway systems at the American continents and the Pacific Ocean. Minimization of distances between tundra breeding sectors and northerly stopover sites, in combination with the Beringia glacial refugium and colonization history, seemed to be important for the evolution of this major polar bird migration system.

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MAKARIKOV, ARSENY A., KURT E. GALBREATH y ERIC P. HOBERG. "Parasite diversity at the Holarctic nexus: species of Arostrilepis (Eucestoda: Hymenolepididae) in voles and lemmings (Cricetidae: Arvicolinae) from greater Beringia". Zootaxa 3608, n.º 6 (23 de enero de 2013): 401–39. http://dx.doi.org/10.11646/zootaxa.3608.6.1.

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Previously unrecognized species of hymenolepidid cestodes attributable to Arostrilepis Mas-Coma & Tenora, 1997 in arvicoline rodents from the greater Beringian region and western North America are described. Discovery and characterization of these tapeworms contributes to the recognition of a complex of cryptic species distributed across the Holarctic region. Three species are proposed: Arostrilepis gulyaevi sp. n. is named for cestodes in Myodes rufocanus from the Republic of Buryatia, southeastern Siberia and from the Khabarovskiy Kray, Chukotka Autonomous Okrug, and Magadanskaya Oblast’, Russian Far East (western Beringia); A. cooki sp. n. is named for cestodes in Myodes gapperi from British Columbia, Canada and Montana, USA; and A. rauschorum sp. n. is named for cestodes in Microtus oeconomus, M. longicaudus, M. pennsylvanicus and M. xanthognathus from the Brooks Range, Seward Peninsula, north-central interior, and Arctic coastal plains of Alaska (eastern Beringia) and Montana, USA. Consistent with recent studies defining diversity in the genus, the form, size, and spination (pattern, shape and size) of the cirrus are diagnostic; species are further distinguished by the relative position and length of the cirrus sac, and arrangement of the testes. Assessment of genetic data from the cytochrome b gene of mitochondrial DNA complements differentiation of this complex based on morphological attributes and confirms known species diversity within the genus. New data for geographical distribution and host specificity of known Arostrilepis spp. indicate that 3 of 12 recognized species have Holarctic distributions extending across Beringia. These include Arostrilepis beringiensis (Kontrimavichus & Smirnova, 1991) in lemmings (species of Lemmus and Synaptomys), A. cf. janickii Makarikov & Kontrimavichus, 2011 in root voles (M. oeconomus) MAKARIKOV ET AL. 402 · Zootaxa 3608 (6) © 2013 Magnolia Press and A. macrocirrosa Makarikov, Gulyaev & Kontrimavichus, 2011 in red backed voles (species of Myodes) and less often other rodent host species.

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Kuzmina, Svetlana. "Wetlands in the Pleistocene Steppe-Tundra Landscapes of Beringia, Their Insects, and the Role of Aeolian Sedimentation". Water 15, n.º 3 (26 de enero de 2023): 494. http://dx.doi.org/10.3390/w15030494.

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Analysis of the database of Beringian subfossil insect assemblages showed a relatively low role of aquatic, riparian, and wetland species of insects with hard exoskeleton in the Pleistocene communities and an increase in their proportions and taxonomic diversity in the Holocene. Aquatic insects were represented in all types of geological deposits and in some paleosols, but their proportions varied in different depositional environments. Poor representation of aquatic insects and a lack of freshwater invertebrates in the Late Pleistocene ice-rich deposits of Beringia called Siberian Yedoma or Yukon Muck attest to the predominantly aeolian origin of this phenomenon.

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Bartlein, P. J., M. E. Edwards, S. W. Hostetler, S. L. Shafer, P. M. Anderson, L. B. Brubaker y A. V. Lozhkin. "Early-Holocene warming in Beringia and its mediation by sea-level and vegetation changes". Climate of the Past 11, n.º 9 (24 de septiembre de 2015): 1197–222. http://dx.doi.org/10.5194/cp-11-1197-2015.

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Abstract. Arctic land-cover changes induced by recent global climate change (e.g., expansion of woody vegetation into tundra and effects of permafrost degradation) are expected to generate further feedbacks to the climate system. Past changes can be used to assess our understanding of feedback mechanisms through a combination of process modeling and paleo-observations. The subcontinental region of Beringia (northeastern Siberia, Alaska, and northwestern Canada) was largely ice-free at the peak of deglacial warming and experienced both major vegetation change and loss of permafrost when many arctic regions were still ice covered. The evolution of Beringian climate at this time was largely driven by global features, such as the amplified seasonal cycle of Northern Hemisphere insolation and changes in global ice volume and atmospheric composition, but changes in regional land-surface controls, such as the widespread development of thaw lakes, the replacement of tundra by deciduous forest or woodland, and the flooding of the Bering–Chukchi land bridge, were probably also important. We examined the sensitivity of Beringia's early Holocene climate to these regional-scale controls using a regional climate model (RegCM). Lateral and oceanic boundary conditions were provided by global climate simulations conducted using the GENESIS V2.01 atmospheric general circulation model (AGCM) with a mixed-layer ocean. We carried out two present-day simulations of regional climate – one with modern and one with 11 ka geography – plus another simulation for 6 ka. In addition, we performed five ~ 11 ka climate simulations, each driven by the same global AGCM boundary conditions: (i) 11 ka Control, which represents conditions just prior to the major transitions (exposed land bridge, no thaw lakes or wetlands, widespread tundra vegetation), (ii) sea-level rise, which employed present-day continental outlines, (iii) vegetation change, with deciduous needleleaf and deciduous broadleaf boreal vegetation types distributed as suggested by the paleoecological record, (iv) thaw lakes, which used the present-day distribution of lakes and wetlands, and (v) post-11 ka All, incorporating all boundary conditions changed in experiments (ii)–(iv). We find that regional-scale controls strongly mediate the climate responses to changes in the large-scale controls, amplifying them in some cases, damping them in others, and, overall, generating considerable spatial heterogeneity in the simulated climate changes. The change from tundra to deciduous woodland produces additional widespread warming in spring and early summer over that induced by the 11 ka insolation regime alone, and lakes and wetlands produce modest and localized cooling in summer and warming in winter. The greatest effect is the flooding of the land bridge and shelves, which produces generally cooler conditions in summer but warmer conditions in winter and is most clearly manifest on the flooded shelves and in eastern Beringia. By 6 ka continued amplification of the seasonal cycle of insolation and loss of the Laurentide ice sheet produce temperatures similar to or higher than those at 11 ka, plus a longer growing season.

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Bartlein, P. J., M. E. Edwards, S. W. Hostetler, S. L. Shafer, P. M. Anderson, L. B. Brubaker y A. V. Lozhkin. "Early-Holocene warming in Beringia and its mediation by sea-level and vegetation changes". Climate of the Past Discussions 11, n.º 2 (30 de marzo de 2015): 873–932. http://dx.doi.org/10.5194/cpd-11-873-2015.

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Abstract. Arctic land-cover changes (e.g., expansion of woody vegetation into tundra and effects of permafrost degradation) that have been induced by recent global climate change are expected to generate further feedbacks to the climate system. Past changes can be used to assess our understanding of feedback mechanisms through a combination of process modelling and paleo-observations. The sub-continental region of Beringia (Northeast Siberia, Alaska, and northwestern Canada) was largely ice-free at the peak of deglacial warming and experienced both major vegetation change and loss of permafrost when many arctic regions were still ice covered. The evolution of Beringian climate at this time was largely driven by global features, such as the amplified seasonal cycle of Northern Hemisphere insolation and changes in global ice volume and atmospheric composition, but changes in regional land-surface controls, such as the widespread development of thaw lakes, the replacement of tundra by deciduous forest or woodland, and the flooding of the Bering–Chukchi land bridge, were probably also important. We examined the sensitivity of Beringia's early Holocene climate to these regional-scale controls using a regional climate model (RegCM). Lateral and oceanic boundary conditions were provided by global climate simulations conducted using the GENESIS V2.01 atmospheric general circulation model (AGCM) with a mixed-layer ocean. We carried out two present day simulations of regional climate, one with modern and one with 11 ka geography, plus another simulation for 6 ka. In addition, we performed five ∼11 ka climate simulations, each driven by the same global AGCM boundary conditions: (i) 11 ka "Control", which represents conditions just prior to the major transitions (exposed land bridge, no thaw lakes or wetlands, widespread tundra vegetation), (ii) sea-level rise, which employed present day continental outlines, (iii) vegetation change, with deciduous needleleaf and deciduous broadleaf boreal vegetation types distributed as suggested by the paleoecological record, (iv) thaw lakes, which used the present day distribution of lakes and wetlands; and (v) post-11 ka "All", incorporating all boundary conditions changed in experiments (ii)–(iv). We find that regional-scale controls strongly mediate the climate responses to changes in the large-scale controls, amplifying them in some cases, damping them in others, and, overall, generating considerable spatial heterogeneity in the simulated climate changes. The change from tundra to deciduous woodland produces additional widespread warming in spring and early summer over that induced by the 11 ka insolation regime alone and lakes and wetlands produce modest and localized cooling in summer and warming in winter. The greatest effect is the flooding of the land bridge and shelves, which produces generally cooler conditions in summer but warmer conditions in winter, and is most clearly manifest on the flooded shelves and in eastern Beringia. By 6 ka continued amplification of the seasonal cycle of insolation and loss of the Laurentide ice sheet produce temperatures similar to or higher than those at 11 ka plus a longer growing season.

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23

Vasilyev, S. A. "Initial peopling of North America: paleogeography and archaeology". Izvestiya Rossiiskoi akademii nauk. Seriya geograficheskaya, n.º 3 (25 de junio de 2019): 131–40. http://dx.doi.org/10.31857/s2587-556620193131-140.

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The paper contains a summary of the new data relevant to the time and routes of the first peopling of the New World. The first unambiguous traces of humans are dated by the time span after the Last Glacial Maximum. The chronology and orientation of prehistoric migrations depended on the Late Pleistocene paleogeography. Instead of a postulated single wave of migration oriented from NW to SE from the Bering Land Bridge via the Mackenzie ice-free corridor to the territory lying southwards from the ice sheets we argue about a complicated picture of human movements of different age and direction. It seems that the earliest inhabitants penetrated from Beringia to the main area of North America following the Pacific coast and later dispersed to the east. The migration along the Mackenzie ice-free corridor should have place later. The Clovis culture seems to originate in the southeastern part of the USA territory then dispersing in northern and western directions along the whole continent. The Final Pleistocene saw the ‘inverse’ migration of the Paleoindians to the north, along the Mackenzie corridor to Beringia.

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24

Shapiro, Beth y Alan Cooper. "Beringia as an Ice Age genetic museum". Quaternary Research 60, n.º 1 (julio de 2003): 94–100. http://dx.doi.org/10.1016/s0033-5894(03)00009-7.

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AbstractThousands of Late Pleistocene remains are found in sites throughout Beringia. These specimens comprise an Ice Age genetic museum, and the DNA contained within them provide a means to observe evolutionary processes within populations over geologically significant time scales. Phylogenetic analyses can identify the taxonomic positions of extinct species and provide estimates of speciation dates. Geographic and temporal divisions apparent in the genetic data can be related to ecological change, human impacts, and possible landscape mosaics in Beringia. The application of ancient DNA techniques to traditional paleontological studies provides a new perspective to long-standing questions regarding the paleoenvironment and diversity of Late Pleistocene Beringia.

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25

Lanoë, François B. y Charles E. Holmes. "Animals as Raw Material in Beringia: Insights from the Site of Swan Point CZ4B, Alaska". American Antiquity 81, n.º 4 (octubre de 2016): 682–96. http://dx.doi.org/10.1017/s0002731600101039.

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We document the use of organic raw material in late Pleistocene eastern Beringia through the study of the site of Swan Point CZ4b, in central Alaska. CZ4b is attributed to the Dyuktai culture and dates to about 14,000 cal B.P. We interpret the occupation as a specialized workshop dedicated to the production and maintenance of organic-based tools following three lines of evidence: (1) limited on-site consumption of megafauna, (2) diversity of organic raw materials and techniques used in processing them, and (3) spatial demarcation of specialized activity areas. Specialized workshops are located in the vicinity of naturally occurring accumulations of mammoth bones in both western and eastern Beringia and suggest similarities in animal resource use across Beringia for the Dyuktai culture. Organic technology was a major portion of Dyuktai technology in eastern Beringia, and its lack of visibility in archaeological assemblages is probably due to taphonomic reasons. Changes in the availability of organic raw material throughout the Late Pleistocene offer some implications for the evolution of lithic technology and material culture.

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26

van den Bogaard, C., B. J. L. Jensen, N. J. G. Pearce, D. G. Froese, M. V. Portnyagin, V. V. Ponomareva y V. Wennrich. "Volcanic ash layers in Lake El'gygytgyn: eight new regionally significant chronostratigraphic markers for western Beringia". Climate of the Past 10, n.º 3 (23 de mayo de 2014): 1041–62. http://dx.doi.org/10.5194/cp-10-1041-2014.

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Abstract. Ash layers from explosive volcanic eruptions (i.e., tephra) represent isochronous surfaces independent from the environment in which they are deposited and the distance from their source. In comparison to eastern Beringia (non-glaciated Yukon and Alaska), few Plio-Pleistocene distal tephra are known from western Beringia (non-glaciated arctic and subarctic eastern Russia), hindering the dating and correlation of sediments beyond the limit of radiocarbon and luminescence methods. The identification of eight visible tephra layers (T0–T7) in sediment cores extracted from Lake El'gygytgyn, in the Far East Russian Arctic, indicates the feasibility of developing a tephrostratigraphic framework for this region. These tephra range in age from ca 45 ky to 2.2 My old, and each is described and characterized by its major-, minor-, trace-element and Pb isotope composition. These data show that subduction-zone-related volcanism from the Kurile–Kamchatka–Aleutian Arc and Alaska Peninsula is the most likely source, with Pb isotope data indicating a Kamchatkan volcanic source for tephra layers T0–T5 and T7, while a source in the Aleutian Arc is possible for tephra T6. The location of Lake El'gygytgyn relative to potential source volcanoes (> 1000 km) suggests these tephra are regionally distributed over a large area. These deposits provide a unique opportunity to correlate the high-resolution paleoenvironmental records of Lake El'gygytgyn to other terrestrial paleoenvironmental archives from western Beringia and marine records from the western North Pacific and Bering Sea, and to move towards the development of a robust integrated framework between the continuous paleoclimatic records of Lake El'gygytgyn and other terrestrial and marine records in NE Eurasia.

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27

van den Bogaard, C., B. J. L. Jensen, N. J. G. Pearce, D. G. Froese, M. V. Portnyagin, V. V. Ponomareva, D. Garbe-Schönberg y V. Wennrich. "Volcanic ash layers in Lake El'gygytgyn: eight new regionally significant chronostratigraphic markers for western Beringia". Climate of the Past Discussions 9, n.º 5 (29 de octubre de 2013): 5977–6034. http://dx.doi.org/10.5194/cpd-9-5977-2013.

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Abstract. Ash layers from explosive volcanic eruptions (i.e. tephra) represent isochronous surfaces independent from the environment in which they are deposited and the distance from their source. In comparison to eastern Beringia (non-glaciated Yukon and Alaska), few Plio-Pleistocene distal tephra are known from western Beringia (non-glaciated arctic and subarctic eastern Russia), hindering the dating and correlation of sediments beyond the limit of radiocarbon and luminescence methods. The identification of eight visible tephra layers (T0–T7) in sediment cores extracted from Lake El'gygytgyn, in the Far East Russian Arctic, indicates the feasibility of developing a tephrostratigraphic framework for this region. These tephra range in age from ca. 45 ka to 2.2 Ma, and each is described and characterized by its major-, minor-, trace-element and Pb isotope composition. These data show that subduction zone related volcanism from the Kurile–Kamchatka–Aleutian–Arc and Alaska Peninsula is the most likely source, with Pb isotope data indicating a Kamchatkan volcanic source for tephra layers T0–T5 and T7, while a source in the Aleutian Arc is possible probable for Tephra T6. The location of Lake El'gygytgyn relative to potential source volcanoes (>1000 km) suggests these tephra are distributed over a vast area. These deposits provide a unique opportunity to correlate the high-resolution paleoenvironmental records of Lake El'gygytgyn to other terrestrial paleoenvironmental archives from western Beringia and marine records from the northwest Pacific and Bering Sea. This is an important first step towards the development of a robust integrated framework between the continuous paleoclimatic records of Lake El'gygytgyn and other terrestrial and marine records in NE Eurasia.

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28

Schweger, Charles E. y John V. Matthews. "Early and Middle Wisconsinan Environments of Eastern Beringia: Stratigraphic and Paleoecological Implications of the Old Crow Tephra". Géographie physique et Quaternaire 39, n.º 3 (4 de diciembre de 2007): 275–90. http://dx.doi.org/10.7202/032608ar.

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ABSTRACTThe widespread Beringian Old Crow tephra occurs in Imuruk Lake (Alaska) core V, above the Blake paleomagnetic event and below Radiocarbon dates, which provide an extrapolated tephra age between 87 000 - 105 000 BP. Exposure KY-11 (Alaska), where the tephra occurs in a dated lacustrine sequence, provides corroboration. Fossil pollen records show that O.C.T. was deposited across northern Beringia on birch-shrub tundra vegetation during an interval of colder climate. A series of climatic oscillations followed tephra deposition. A prolonged period of cold-arid climate ( = marine isotope Stage 4) preceded an interval of warmer than present climate starting ca. 60 000 BP (beginning Stage 3). During this interval, designated the Koy-Yukon thermal event, an exposed Bering land bridge promoted an interglacial type climate that led to significant biotic changes and permafrost degradation. O.C.T. occurs on drift of the Mirror Creek Glaciation which is equivalent to other presumed Early Wisconsinan glaciations in Alaska and Yukon. These glaciations could not have occurred later than marine Stage 5. Stage 4 was fully as cold as Stage 2 (Late Wisconsinan), yet seems not to have been a time of extensive glaciation. The Middle Wisconsinan, 30 000 to more than 80 000 BP, was a nonglacial interval with several climate fluctuations, one of which, the Koy-Yukon thermal event, was warmer than at present.

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29

Elias, Scott A. "Climatic tolerances and zoogeography of the late Pleistocene beetle fauna of Beringia". Géographie physique et Quaternaire 54, n.º 2 (2 de octubre de 2002): 143–55. http://dx.doi.org/10.7202/004813ar.

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Abstract The study of fossil beetles has played an important role in the reconstruction of Beringian paleoenvironments. More than 25 fossil localities have yielded Late Pleistocene beetle assemblages, comprising more than 300 species, of which about 147 are predators and scavengers, groups which are suitable for paleoclimatic reconstruction. The author has developed climate envelopes (climatic parameters characterizing the modern localities in which species are found) for these species, in order to perform mutual climatic range pale- otemperature studies. This paper describes the thermal requirements of these beetles, and their zoogeographic history since the interval just prior to the last interglacial period. The fossil assemblages include 14 arctic and alpine species, 66 boreo-arctic species, and 68 boreal and temperate species. The greatest percentage of species with restricted thermal requirements occurs in the arctic and alpine group. The majority of boreo-arctic and boreal and temperate species have very broad thermal requirements. Based on modern distribution and the North American fossil record, it appears that some species resided exclusively in Beringia during the Late Pleistocene. These Beringian species comprise 64 % of the arctic and alpine species found in the fossil assemblages, 34 % of the boreo-arctic species, and only 1 % of the boreal and temperate species.

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30

Burke, Ariane y Jacques Cinq-Mars. "Dental Characteristics of Late Pleistocene Equus Lambei from the Bluefish Caves, Yukon Territory, and their Comparison with Eurasian Horses". Géographie physique et Quaternaire 50, n.º 1 (30 de noviembre de 2007): 81–93. http://dx.doi.org/10.7202/033077ar.

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ABSTRACT Bluefish Caves I, II and III of northern Yukon, have yielded the earliest in situ evidence of human occupation of Eastern Beringia, associated with one of the largest and most diverse Late Pleistocene faunas recovered in the region. This paper presents data derived from the study of a large sample of horse teeth recovered from the three caves. This research contributes to our knowledge of the Late Pleistocene Beringian equid, Equus lambei. A comparison of the dentition of E. lambei with that of some contemporary European horses, indicates they have similar size cheekteeth. The hypothesis of a Late Pleistocene trend of size reduction in equids is considered in the light of this comparison.

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31

Hoffecker, John F. y Scott A. Elias. "Environment and archeology in Beringia". Evolutionary Anthropology: Issues, News, and Reviews 12, n.º 1 (14 de febrero de 2003): 34–49. http://dx.doi.org/10.1002/evan.10103.

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32

Hoffecker, John, Vladimir Pitulko y Elena Pavlova. "Beringia and the Settlement of the Western Hemisphere". Vestnik of Saint Petersburg University. History 67, n.º 3 (2022): 882–909. http://dx.doi.org/10.21638/spbu02.2022.313.

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Previously, we addressed the problem of what variable(s) limited widespread human settlement of the Americas before ~15 ka. We concluded that while non-modern human taxa (e. g., Neanderthals) probably did not inhabit high-latitude environments (due to cold climate and/ or low plant and animal productivity) and thus could not disperse in the Western Hemispherevia Beringia, modern humans likely were denied access to mid-latitude North America >15 ka by coastal and interior ice sheets. Here we reexamine the problem with respect to modern humans in light of a revised chronology for glaciers and sea level, new research in paleo-genomics, and some new archaeological discoveries. During 35–30 ka, a lineage with west Eurasian roots occupied the Great Arctic Plain and may have expanded into eastern arctic Beringia and mid-latitude North America via an ice-free corridor. An East Asian lineage associated with microblade technology occupied the Lena Basin during the LGM and expanded onto the Great Arctic Plain >15 ka, possibly as early as the GI 2 interstadial (24–23 ka). Their immediate descendants probably occupied the southern Bering Land Bridge and Northwest Pacific coast >15 ka and dispersed widely in the Western Hemisphere during GI 1 (14.5–12.9 ka), primarily if not exclusively via a coastal route. The coalesced Laurentide and Cordilleran ice sheets blocked interior access to mid-latitude America until 13.8 ± 0.5 ka (and possibly later due to the length and narrow width of the ice-free corridor >13 ka).

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33

Lafontaine, J. D. y V. S. Kononenko. "A REVIEW OF THE GENUS PARABARROVIA GIBSON (LEPIDOPTERA: NOCTUIDAE) WITH DESCRIPTION OF THE IMMATURE STAGES AND A NEW SPECIES". Canadian Entomologist 120, n.º 6 (junio de 1988): 507–23. http://dx.doi.org/10.4039/ent120507-6.

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AbstractThe genus Parabarrovia Gibson, with one included species, P. keelei Gibson, was previously known from the original type material collected in the MacKenzie Mountains, Northwest Territories, in northern Canada. The known range of P. keelei is extended to include other areas in Beringia, namely, Yukon (British Mountains), Alaska (Brooks Range and Seward Peninsula), and the USSR (Wrangel Island). The immature stages are described for the first time. A second species of Parabarrovia, P. ogilviensis Lafontaine, also known only from the Beringian area, is described from the Ogilvie Mountains, Yukon, Canada. The position of Parabarrovia within the Noctuidae is reviewed and the genus is tentatively retained within the subfamily Noctuinae. Adults, including genital characters, and the immature stages are described and illustrated for both species.

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34

Heintzman, Peter D., Duane Froese, John W. Ives, André E. R. Soares, Grant D. Zazula, Brandon Letts, Thomas D. Andrews et al. "Bison phylogeography constrains dispersal and viability of the Ice Free Corridor in western Canada". Proceedings of the National Academy of Sciences 113, n.º 29 (6 de junio de 2016): 8057–63. http://dx.doi.org/10.1073/pnas.1601077113.

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The Ice Free Corridor has been invoked as a route for Pleistocene human and animal dispersals between eastern Beringia and more southerly areas of North America. Despite the significance of the corridor, there are limited data for when and how this corridor was used. Hypothetical uses of the corridor include: the first expansion of humans from Beringia into the Americas, northward postglacial expansions of fluted point technologies into Beringia, and continued use of the corridor as a contact route between the north and south. Here, we use radiocarbon dates and ancient mitochondrial DNA from late Pleistocene bison fossils to determine the chronology for when the corridor was open and viable for biotic dispersals. The corridor was closed after ∼23,000 until 13,400 calendar years ago (cal y BP), after which we find the first evidence, to our knowledge, that bison used this route to disperse from the south, and by 13,000 y from the north. Our chronology supports a habitable and traversable corridor by at least 13,000 cal y BP, just before the first appearance of Clovis technology in interior North America, and indicates that the corridor would not have been available for significantly earlier southward human dispersal. Following the opening of the corridor, multiple dispersals of human groups between Beringia and interior North America may have continued throughout the latest Pleistocene and early Holocene. Our results highlight the utility of phylogeographic analyses to test hypotheses about paleoecological history and the viability of dispersal routes over time.

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35

Ickert-Bond, Stefanie M., David Murray, Margaret G. Oliver, Hazel K. Berrios y Campbell O. Webb. "The Claytonia arctica Complex in Alaska—Analyzing a Beringian Taxonomic Puzzle Using Taxonomic Concepts". Annals of the Missouri Botanical Garden 104, n.º 3 (11 de septiembre de 2019): 478–94. http://dx.doi.org/10.3417/2019491.

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Trans-Beringia taxa often present complex puzzles for taxonomists, a reflection of differing traditions and opinions, taxonomic approaches, and access to material from both sides of the Bering Strait. There is wide biological variation in perceived or circumscribed taxa whose populations are widespread within the regions and yet biogeographically isolated in Asia and/or America. The Claytonia arctica complex is one such example; it illustrates these issues well and has been dealt with by North American and Russian botanists in decidedly different ways. We reviewed specimens and examined the various taxonomic concepts of C. arctica through time and source publications. The relationships (alignments) among taxonomic concepts are presented in a graphical format. We found that much of the confusion related to C. arctica in Beringia stems from overlookingC. scammaniana Hultén sensu Hultén (1939), and placing too much emphasis on the woody caudex and perennation structures, during the creation of two taxonomic concepts: C. arctica Adams sensu Porsild and C. porsildii Jurtzev sensu Yurtsev. The C. arctica complex (in our current sense) is an evolutionary work in progress, resulting in partially differentiated races with much overlapping variability and intergradation of characters (particularly in C. scammaniana according to our current sense) that have not reached the level of stability (i.e., individuals may still intergrade freely) usually associated with the concept of species in other arctic lineages.

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36

Babenko, A. y A. Fjellberg. "Onychiuridae (Collembola) of the Western Beringia". Зоологический журнал 95, n.º 8 (2016): 905–30. http://dx.doi.org/10.7868/s0044513416060039.

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37

Hoffecker, John F., Scott A. Elias y Olga Potapova. "Arctic Beringia and Native American Origins". PaleoAmerica 6, n.º 2 (20 de febrero de 2020): 158–68. http://dx.doi.org/10.1080/20555563.2020.1725380.

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38

Ray, G. Carleton, Jerry McCormick-Ray, Peter Berg y Howard E. Epstein. "Pacific walrus: Benthic bioturbator of Beringia". Journal of Experimental Marine Biology and Ecology 330, n.º 1 (marzo de 2006): 403–19. http://dx.doi.org/10.1016/j.jembe.2005.12.043.

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39

Gaglioti, Benjamin V., Brian M. Barnes, Grant D. Zazula, Alwynne B. Beaudoin y Matthew J. Wooller. "Late Pleistocene paleoecology of arctic ground squirrel (Urocitellus parryii) caches and nests from Interior Alaska's mammoth steppe ecosystem, USA". Quaternary Research 76, n.º 3 (noviembre de 2011): 373–82. http://dx.doi.org/10.1016/j.yqres.2011.08.004.

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AbstractBotanical analyses of fossil and modern arctic ground squirrel (Urocitellus parryii) caches and nests have been used to reconstruct the past vegetation from some parts of Beringia, but such archives are understudied in Alaska. Five modern and four fossil samples from arctic ground squirrel caches and nests provide information on late Pleistocene vegetation in Eastern Beringia. Modern arctic ground squirrel caches from Alaska's arctic tundra were dominated by willow and grass leaves and grass seeds and bearberries, which were widespread in the local vegetation as confirmed by vegetation surveys. Late Pleistocene caches from Interior Alaska were primarily composed of steppe and dry tundra graminoid and herb seeds. Graminoid cuticle analysis of fossil leaves identifiedCalamagrostis canadensis,Koeleriasp. andCarex albonigraas being common in the fossil samples. Stable carbon isotopes analysis of these graminoid specimens indicated that plants using the C3photosynthetic pathways were present and functioning with medium to high water-use efficiency. Fossil plant taxa and environments from ground squirrel caches in Alaska are similar to other macrofossil assemblages from the Yukon Territory, which supports the existence of a widespread mammoth steppe ecosystem type in Eastern Beringia that persisted throughout much of the late Pleistocene.

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40

Surovell, Todd A., Spencer R. Pelton, Richard Anderson-Sprecher y Adam D. Myers. "Test of Martin’s overkill hypothesis using radiocarbon dates on extinct megafauna". Proceedings of the National Academy of Sciences 113, n.º 4 (26 de octubre de 2015): 886–91. http://dx.doi.org/10.1073/pnas.1504020112.

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Following Martin [Martin PS (1973) Science 179:969–974], we propose the hypothesis that the timing of human arrival to the New World can be assessed by examining the ecological impacts of a small population of people on extinct Pleistocene megafauna. To that end, we compiled lists of direct radiocarbon dates on paleontological specimens of extinct genera from North and South America with the expectation that the initial decline of extinct megafauna should correspond in time with the initial evidence for human colonization and that those declines should occur first in eastern Beringia, next in the contiguous United States, and last in South America. Analyses of spacings and frequency distributions of radiocarbon dates for each region support the idea that the extinction event first commenced in Beringia, roughly 13,300–15,000 BP. For the United States and South America, extinctions commenced considerably later but were closely spaced in time. For the contiguous United States, extinction began at ca. 12,900–13,200 BP, and at ca. 12,600–13,900 BP in South America. For areas south of Beringia, these estimates correspond well with the first significant evidence for human presence and are consistent with the predictions of the overkill hypothesis.

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41

Graf, Kelly E. y Ian Buvit. "Human Dispersal from Siberia to Beringia: Assessing a Beringian Standstill in Light of the Archaeological Evidence". Current Anthropology 58, S17 (diciembre de 2017): S583—S603. http://dx.doi.org/10.1086/693388.

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42

Muradrasoli, Shaman, Ádám Bálint, John Wahlgren, Jonas Waldenström, Sándor Belák, Jonas Blomberg y Björn Olsen. "Prevalence and Phylogeny of Coronaviruses in Wild Birds from the Bering Strait Area (Beringia)". PLoS ONE 5, n.º 10 (29 de octubre de 2010): e13640. http://dx.doi.org/10.1371/journal.pone.0013640.

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43

Chlachula, Jiri. "Across Beringia: The Palaeolithic Peopling of Canada". Vestnik of Saint Petersburg University. History 64, n.º 2 (2019): 356–89. http://dx.doi.org/10.21638/11701/spbu02.2019.202.

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44

Zazula, Grant D., Duane G. Froese, Charles E. Schweger, Rolf W. Mathewes, Alwynne B. Beaudoin, Alice M. Telka, C. Richard Harington y John A. Westgate. "Ice-age steppe vegetation in east Beringia". Nature 423, n.º 6940 (junio de 2003): 603. http://dx.doi.org/10.1038/423603a.

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45

Savidge, Rodney Arthur. "Evidence for early glaciation of southeastern Beringia". Canadian Journal of Earth Sciences 57, n.º 2 (febrero de 2020): 199–226. http://dx.doi.org/10.1139/cjes-2019-0048.

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Between the Klondike Plateau and Yukon–Tanana highlands of Yukon and Alaska, respectively, current maps explain glaciated alpine locales and periglacial areas in terms of localized Pliocene–Pleistocene montane ice caps, alpine glaciers, and periglacial changes. However, this region’s plateau topography is populated with long undulating ridges having wide flattened tops; it contrasts with relief of other regions of northwestern North America also affected by ice caps, cryoplanation, and erosion over similar duration during the same epochs. This region has received minimal research and appears to present a new opportunity for resolving outstanding glaciological and stratigraphy issues. The glaciological history is reviewed, placing particular emphasis upon the low-elevation ridges within the “unglaciated” region, suggesting that those ridges are relict arête/cirque remnants. Sites of subalpine glacial grooving and mountaintop planing are also identified, and a conglomeratic red bed containing erratic clasts is described. All indications point to the “unglaciated” region having been glaciated before late Pliocene. Two working hypotheses are proposed: (1) The landscape once supported a range of young mountains that became glaciated then overridden and pared to a plateau by an ice sheet. (2) Following deglaciation, an extended period of paraglacial activity removed most of the former drift and excised new valleys to give the region an unglaciated appearance, which thereafter became modified into its present state by local montane/alpine glaciations, interglacial cryoplanation, periglacial gelifraction, and erosion. In addition to Pliocene–Pleistocene glaciations, a northeastward advancing Miocene ice sheet seems plausible and, on the basis of paleographic considerations and lithology, a Cretaceous glaciation evidently is also not out of the question.

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46

Kunz, M. L. y R. E. Reanier. "Paleoindians in Beringia: Evidence from Arctic Alaska". Science 263, n.º 5147 (4 de febrero de 1994): 660–62. http://dx.doi.org/10.1126/science.263.5147.660.

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47

Lanoë, François B., Joshua D. Reuther, Charles E. Holmes y Gregory W. L. Hodgins. "Human paleoecological integration in subarctic eastern Beringia". Quaternary Science Reviews 175 (noviembre de 2017): 85–96. http://dx.doi.org/10.1016/j.quascirev.2017.10.003.

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48

Wolfe, Jack A. "An analysis of Neogene climates in Beringia". Palaeogeography, Palaeoclimatology, Palaeoecology 108, n.º 3-4 (abril de 1994): 207–16. http://dx.doi.org/10.1016/0031-0182(94)90234-8.

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Lado, Paula y Hans Klompen. "Evolutionary history of New World ticks of the genus Dermacentor (Ixodida: Ixodidae), and the origin of D. variabilis". Biological Journal of the Linnean Society 127, n.º 4 (24 de mayo de 2019): 863–75. http://dx.doi.org/10.1093/biolinnean/blz063.

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Abstract This study integrates biogeographical and phylogenetic data to determine the evolutionary history of the New World Dermacentor, and the origin of D. variabilis. The phylogenetic reconstructions presented here strongly support the hypothesis of an Afrotropical origin for Dermacentor, with later dispersal to Eurasia and the Nearctic. Phylogenetic and biogeographical data suggest that the genus reached the New World through the Beringia land bridge, from south-east Asia. The monophyly of the genus is supported, and most of the New World Dermacentor species appear as monophyletic. Dermacentor occidentals constitutes the sister lineage of D. variabilis, and the latter is subdivided into two well-supported clades: an eastern and a western clade. The western clade is genetically more variable than the eastern. The genus Dermacentor probably originated in Africa, and dispersed to the Palearctic and then to the New World through the Beringian route. Dermacentor variabilis appears to have originated in western North America, and then dispersed to eastern North America, probably in a single migration event.

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50

Billington, Neil, Paul D. N. Hebert y Robert D. Ward. "Allozyme and Mitochondrial DNA Variation among Three Species of Stizostedion (Percidae): Phylogenetic and Zoogeographical Implications". Canadian Journal of Fisheries and Aquatic Sciences 47, n.º 6 (1 de junio de 1990): 1093–102. http://dx.doi.org/10.1139/f90-126.

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The percid genus Stizostedion consists of five species, three in Europe and two in North America, and is believed to have evolved in Europe and then later colonized North America. Three hypotheses exist concerning the route and timing of this colonization: a Miocene Atlantic "riverine" route; a Pliocene Beringian route; and a late-Pleistocene Atlantic route. To test these hypotheses, allozyme and mitochondrial DNA variation were compared in three Stizostedion species, S. canadense and S. vitreum from North America, and S. lucioperca from Europe, to determine their genetic relatedness. Divergence times between S. canadense and S. vitreum were estimated as 3.12 ± 1.33 million years before present (MYBP) from allozyme data and 4.06 ± 0.73 MYBP for mtDNA data, while divergence times between the North American species and S. lucioperca were 10.59 ± 2.74 MYBP and 7.86 ± 1.18 MYBP, respectively. These results are concordant with the hypothesis that colonization of North America by Stizostedion occurred during the Pliocene via Beringia.

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Artículos de revistas sobre el tema "Beringia"

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