Journal articles on the topic 'Pleistocene Climate Changes'
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Diester-Haass, Liselotte, Katharina Billups, and Caroline Lear. "Productivity changes across the mid-Pleistocene climate transition." Earth-Science Reviews 179 (April 2018): 372–91. http://dx.doi.org/10.1016/j.earscirev.2018.02.016.
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Vakulenko, N. V., V. M. Kotlyakov, F. Lambert, and D. M. Sonechkin. "The role of the ocean in pleistocene climate changes." Doklady Earth Sciences 432, no. 1 (May 2010): 659–62. http://dx.doi.org/10.1134/s1028334x10050235.
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Mäder, Geraldo, Priscilla M. Zamberlan, Ana Lucia A. Segatto, João R. Stehmann, Sandro L. Bonatto, and Loreta B. Freitas. "When phylogeography meets niche suitability to unravel the evolutionary history of a shrub from the Brazilian Atlantic Forest." Botanical Journal of the Linnean Society 195, no. 1 (September 3, 2020): 77–92. http://dx.doi.org/10.1093/botlinnean/boaa073.
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Abstract The Brazilian Atlantic Forest (BAF) is one of the most impacted biomes in the world, and in this region, there are several examples of the effects of Pleistocene climate changes among the species found there. Athenaea fasciculata (Solanaceae) is a forest component distributed mainly throughout the BAF extension. Here, we investigated the genetic diversity and population structure of A. fasciculata based on plastid and nuclear markers, aiming to better understand the impact of Pleistocene climate changes on BAF vegetation. We used population genetics, demographic methods and ecological niche modelling coupled to an evolutionary approach to describe the species distribution across time. The phylogeographic analysis of A. fasciculata indicated that Pleistocene climate changes played an important role in its evolution. The species is structured in two groups of populations that emerged from different refugia and were under different climate influences, supporting previously proposed connections between the Atlantic and Amazon Forests, the two most important Neotropical rainforests.
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Bender, Adrian M., Richard O. Lease, Lee B. Corbett, Paul R. Bierman, Marc W. Caffee, James V. Jones, and Doug Kreiner. "Yukon River incision drove organic carbon burial in the Bering Sea during global climate changes at 2.6 and 1 Ma." Earth Surface Dynamics 10, no. 5 (October 28, 2022): 1041–53. http://dx.doi.org/10.5194/esurf-10-1041-2022.
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Abstract. River erosion affects the carbon cycle and thus climate by exporting terrigenous carbon to seafloor sediment and by nourishing CO2-consuming marine life. The Yukon River–Bering Sea system preserves rare source-to-sink records of these processes across profound changes in global climate during the past 5 million years (Ma). Here, we expand the terrestrial erosion record by dating terraces along the Charley River, Alaska, and explore linkages among previously published Yukon River tributary incision chronologies and Bering Sea sedimentation. Cosmogenic 26Al/10Be isochron burial ages of Charley River terraces match previously documented central Yukon River tributary incision from 2.6 to 1.6 Ma during Pliocene–Pleistocene glacial expansion, and at 1.1 Ma during the 1.2–0.7 Ma Middle Pleistocene climate transition. Bering Sea sediments preserve 2–4-fold rate increases of Yukon River-derived continental detritus, terrestrial and marine organic carbon, and silicate microfossil deposition at 2.6–2.1 and 1.1–0.8 Ma. These tightly coupled records demonstrate elevated terrigenous nutrient and carbon export and concomitant Bering Sea productivity in response to climate-forced Yukon River incision. Carbon burial related to accelerated terrestrial erosion may contribute to CO2 drawdown across the Pliocene–Pleistocene and Middle Pleistocene climate transitions observed in many proxy records worldwide.
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Timmermann, Axel, Kyung-Sook Yun, Pasquale Raia, Jiaoyang Ruan, Alessandro Mondanaro, Elke Zeller, Christoph Zollikofer, et al. "Climate effects on archaic human habitats and species successions." Nature 604, no. 7906 (April 13, 2022): 495–501. http://dx.doi.org/10.1038/s41586-022-04600-9.
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AbstractIt has long been believed that climate shifts during the last 2 million years had a pivotal role in the evolution of our genus Homo1–3. However, given the limited number of representative palaeo-climate datasets from regions of anthropological interest, it has remained challenging to quantify this linkage. Here, we use an unprecedented transient Pleistocene coupled general circulation model simulation in combination with an extensive compilation of fossil and archaeological records to study the spatiotemporal habitat suitability for five hominin species over the past 2 million years. We show that astronomically forced changes in temperature, rainfall and terrestrial net primary production had a major impact on the observed distributions of these species. During the Early Pleistocene, hominins settled primarily in environments with weak orbital-scale climate variability. This behaviour changed substantially after the mid-Pleistocene transition, when archaic humans became global wanderers who adapted to a wide range of spatial climatic gradients. Analysis of the simulated hominin habitat overlap from approximately 300–400 thousand years ago further suggests that antiphased climate disruptions in southern Africa and Eurasia contributed to the evolutionary transformation of Homo heidelbergensis populations into Homo sapiens and Neanderthals, respectively. Our robust numerical simulations of climate-induced habitat changes provide a framework to test hypotheses on our human origin.
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Jiménez-Moreno, Gonzalo, Hülya Alçiçek, M. Cihat Alçiçek, Lars van den Hoek Ostende, and Frank P. Wesselingh. "Vegetation and climate changes during the late Pliocene and early Pleistocene in SW Anatolia, Turkey." Quaternary Research 84, no. 3 (November 2015): 448–56. http://dx.doi.org/10.1016/j.yqres.2015.09.005.
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Pollen analysis was done on lacustrine sedimentary sequences dated by micromammals as late Pliocene–early Pleistocene that outcrop in two Neogene graben basins from SW Turkey. This study shows vegetation changes from steppe-like to more forested environments, very similar to the cyclic oscillations related to late Pleistocene glacial–interglacial climate changes. Artemisia was abundant during cold–arid periods, indicating that this species was already widespread in this area during the latest Pliocene and the beginning of the Pleistocene. A review of pollen records from Anatolia agrees with this study, suggesting that the spreading of this arid species occurred during a major climatic change: the beginning of the first glaciations and probably a change in seasonality towards summer aridity. Artemisia temporarily disappeared from the region during warm–wet periods and thus we suggest that glacial–interglacial-type oscillations already occurred in the area during the late Pliocene–early Pleistocene.
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Mazza, Paul P. A., and Adele Bertini. "Were Pleistocene hippopotamuses exposed to climate-driven body size changes?" Boreas 42, no. 1 (October 24, 2012): 194–209. http://dx.doi.org/10.1111/j.1502-3885.2012.00285.x.
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Takakura, Jun. "Rethinking the Disappearance of Microblade Technology in the Terminal Pleistocene of Hokkaido, Northern Japan: Looking at Archaeological and Palaeoenvironmental Evidence." Quaternary 3, no. 3 (July 20, 2020): 21. http://dx.doi.org/10.3390/quat3030021.
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Archaeological research, for several decades, has shown that various microblade technologies using obsidian and hard shale appeared and developed from the Last Glacial Maximum to the terminal Pleistocene (Bølling–Allerød–Younger Dryas) in Hokkaido, Northern Japan. It is well accepted that microblade technology was closely related to the high mobility of foragers to adapt to harsh environments. Recent archaeological and palaeoenvironmental evidence from Hokkaido demonstrates that the disappearance of microblade technology occurred during the terminal Pleistocene, influenced by a wide range of factors, including changes in landscape, climate, subsistence and human populations. The goal of this paper is to provide an overview of the current state of research on the process and background of the disappearance of microblade technology and to discuss prospects for future research. This paper will (1) review palaeoenvironmental research in Hokkaido on changes in climate and biological composition from the terminal Pleistocene to the initial Holocene; (2) survey changes in the technological adaptations and resource use of humans based on the archaeological evidence; and (3) discuss how the abrupt fluctuations of climate that occurred in the terminal Pleistocene affected human behaviour and demographics in Hokkaido.
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Sirenko, О. А. "CHANGES IN THE CLIMATE AND DENDROFLORA OF THE NORTHEASTERN PART OF UKRAINE IN THE LATE MIOCENE—EARLY PLEISTOCENE (ACCORDING TO PALYNOLOGICAL DATA)." Ukrainian geographical journal 2022, no. 3 (November 2022): 21–28. http://dx.doi.org/10.15407/ugz2022.03.021.
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The results of palynological studies serve as the basis for paleofloristic and paleoclimatic reconstructions. Plants are sensitive to changes in basic climatic parameters—heat and moisture. In this regard, the flora is a reliable indicator of changes in paleoclimatic conditions. The purpose of this study is the paleofloristic and paleoclimatic reconstructions of the late Miocene—early Pleistocene of the northeastern part of Ukraine based on palynological data. For the regions of Dnieper-Donetsk depression and the central part of the Donetsk folded structure, detailed reconstructions of paleoclimate changes from the late Miocene to the Pliocene based on palynological data are presented for the first time. The information on climatic changes during the Gelasian time of the early Pleistocene of these regions has been significantly supplemented. Paleoclimate reconstructions were carried out on the basis of analysis of the taxonomic composition of spore-pollen complexes and subcomplexes that characterize Upper Miocene-Lower Pleistocene sediments, analysis of ecological timing of individual taxa, as well as analysis of geographical elements of flora and patterns of changes in their relationships over time. It is established that the climate of the late Miocene, Pliocene, and early Pleistocene of the northeastern part of Ukraine was characterized by cyclicity of different frequencies and amplitude. Climatic optimums and pessimums traced in the specified period of time are characterized. The curves of changes in the main climate parameters of the northeastern part of Ukraine in the late Miocene-early Pleistocene are represented.
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Rousseau, Denis-Didier, Witold Bagniewski, and Michael Ghil. "Abrupt climate changes and the astronomical theory: are they related?" Climate of the Past 18, no. 2 (February 11, 2022): 249–71. http://dx.doi.org/10.5194/cp-18-249-2022.
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Abstract. Abrupt climate changes are defined as sudden climate changes that took place over tens to hundreds of years or recurred at millennial timescales; they are thought to involve processes that are internal to the climate system. By contrast, astronomically forced climate changes involve processes that are external to the climate system and whose multi-millennial quasi-periodic variations are well known from astronomical theory. In this paper, we re-examine the main climate variations determined from the U1308 North Atlantic marine record, which yields a detailed calving history of the Northern Hemisphere ice sheets over the past 3.2 Myr. The magnitude and periodicity of the ice-rafted debris (IRD) events observed in the U1308 record allow one to determine the timing of several abrupt climate changes, the larger ones corresponding to the massive iceberg discharges labeled Heinrich events (HEs). In parallel, abrupt warmings, called Dansgaard–Oeschger (DO) events, have been identified in the Greenland records of the last glaciation cycle. Combining the HE and DO observations, we study a complex mechanism giving rise to the observed millennial-scale variability that subsumes the abrupt climate changes of last 0.9 Myr. This process is characterized by the presence of Bond cycles, which group DO events and the associated Greenland stadials into a trend of increased cooling, with IRD events embedded into every stadial, the latest of these being an HE. These Bond cycles may have occurred during the last 0.9 Ma when Northern Hemisphere ice sheets reached their maximum extent and volume, thus becoming a major player in this time interval's climate dynamics. Since the waxing and waning of ice sheets during the Quaternary period are orbitally paced, we conclude that the abrupt climate changes observed during the Middle Pleistocene and Upper Pleistocene are therewith indirectly linked to the astronomical theory of climate.
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Seitz, Carina, María I. Vélez, and Gerardo M. E. Perillo. "Cenozoic geologic evolution of the lower Colorado River Basin, Northern Patagonia, Argentina." Andean Geology 46, no. 1 (September 28, 2018): 131. http://dx.doi.org/10.5027/andgeov46n1-3060.
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Climatic changes and eustatic sea levels have been assumed to be the most important controllers of the Colorado River alluvial fan in northern Patagonia. Although the alluvial fan occurs in a region considered tectonically stable, there are pieces of evidence that the Miocene Andean orogeny has reactivated inherited structures, with subsequent geomorphological changes that date back to the Pleistocene. Besides, the clear evidence of neotectonism in the region and their effects on the evolution of this fan, it has not been studied in detail yet. In this study, we map and analyze six sections outcropping in different terraces of the alluvial fan with the primary aim of disentangling the role of tectonism, climate and eustatic changes on the evolution of the alluvial fan. This study is part of a bigger project aimed to understand the origin of the shallow lakes occurring in northern Patagonia. Our results indicate that the alluvial fan of the Colorado River was established in the area around the Middle Pleistocene. Evidence of deformations in Miocene to Pleistocene units indicates significant neotectonism during the Upper Pleistocene. By the Pleistocene-Holocene transition, tectonism produced incision generating a set of terraces. After this time, an important climate change from semiarid to arid favored the calcretization of some terraces. By the Pleistocene-Middle Holocene, the terraces were covered by ancient eolian sediment accumulated during dry conditions. By the Middle Holocene, a broad alluvial fan developed in the region under a warmer and more humid climate generating the Alluvial Colorado River-III deposit at the T3 terrace. In the late Holocene, aggradation process was favored by a high sea level and temperate-arid climate, producing T4 terrace. At the same time, this climate condition favored the local deflation-sedimentation processes that resulted in the deposition of modern eolian deposits (mE) over the T3 terrace. The depressions generated by the deflation were, later on, occupied by shallow lakes when the climate turn more humid. Subsequently, during regressive sea level condition, ca. 2000 years BP, the T4 terrace was partially eroded and the modern alluvial plain formed.
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DOTSENKO, Valeriy, and Ibragim KERIMOV. "ABOUT THE REASONS OF CLIMATE WARMING BASED ON STUDYING THE HISTORY OF QUATERNARY GLACIOSES OF THE CAUCASUS (ON THE EXAMPLE OF THE INTERDURCHIE TEREK AND THE ANDIAN KOISU)." Sustainable Development of Mountain Territories 12, no. 3 (September 30, 2020): 461–71. http://dx.doi.org/10.21177/1998-4502-2020-12-3-461-471.
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The Greater Caucasus experienced repeated glaciation during the Quaternary (early, middle, upper Pleistocene, late Glacial, and late Holocene), which occurred under changing climatic conditions and differentiated tectonic movements. These glaciations, of course, are associated with changes in terrain, the formation of new deposits, transgressions and regressions of the Caspian Sea, changes in vegetation and soil types, so the problem of glaciation affects all earth Sciences to varying degrees. The study of Quaternary glaciation, especially Holocene glaciation, is currently relevant for understanding climate change. Against the background of significant climate fluctuations within the epochs of glaciation, there are smaller cooling phases that cause the temporary onset of glaciers. Short-term climate fluctuations are manifested in oscillations – minor fluctuations in the languages of glaciers. All this indicates that the climate undergoes significant changes in a short time, which are reflected in the morphosculpture of the terrain, the latest deposits and modern precipitation. Glaciation of the Greater Caucasus in the Prikazbeksky region reached its maximum in the middle Pleistocene,when glaciers went far into the Ossetian basin. All these traces have been preserved due to the lower capacity of the Chanty-Argun glacier and its fluvioglacial flow, which developed during the late Pleistocene epoch. Volcanic activity, especially active in the late Pliocene and continuing up to the present time, is associated with the late horn stage of development of the Caucasus. The formation of the Rukhs-Dzuar molass formation more than 2 km thick in the late Pleistocene in the Ossetian basin of the Tersky-Caspian flexure is associated with the activity of volcanoes in the Kazbek volcanic region. In the early Pleistocene, volcanic activity on the BC decreased significantly. The most intense outbreak of volcanism in the Kazbek and Elbrus volcanic regions occurred at the beginning of the late Pleistocene, which roughly coincided with the maximum phase of the late Pleistocene (Bezengian) glaciation. Then, in the second half of the late Pleistocene, volcanic activity was manifested on the mount Kazbek. The last outbreak of volcanic activity occurred in the Holocene no more than 2-3 thousand years ago. Fresh lavas are available on Elbrus, Kazbek, in the Terek valley near villages. Sioni and on the Kel volcanic plateau. Fumarolic activity still continues on Elbrus. Thus, in the Kazbek region, eruptions occurred from the late Pliocene to the late Holocene inclusive. Keywords: Pleistocene, Holocene, glaciation stages, nival-glacial processes, causes of glaciations, climate change, anthropogenic factors, natural factors, Earth degassing, magmatogenic degassing branch, seismotectonic degassing branch, greenhouse gases, newest geodynamics, volcanism, mud regimes, volcanism, methane hydrates, land degradation, water reclamation.
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Graham, Russell W. "Response of North American mammal communities to late Quaternary environmental fluctuations." Paleontological Society Special Publications 6 (1992): 112. http://dx.doi.org/10.1017/s2475262200006729.
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The late Quaternary was a time of rapid environmental fluctuations. The last glacial maximum was reached about 20 ka with continental glaciers covering most of Canada as well as the northeastern and upper midwestern United States (U.S.). Glacial ice physically displaced entire terrestrial biomes and the cooler climates altered distributions of species outside of the glacial limits. About 14 ka, the climate began to warm rapidly and glacial ice retreated northward, opening new landscapes for colonization by terrestrial biotas. Maximum warmth was reached between 9–5 ka with a time transgressive progression from west to east.Radiocarbon chronologies allow for fine scale (100's to 1000's of years) resolution of mammal responses to these changes. Mammal communities did not respond as intact units but individual species shifted diachronically along environmental gradients. As a result, many late Pleistocene mammal communities contain associations of extant species that do not occur together today and appear to be ecologically incompatible. Pleistocene mammal communities also had a greater diversity of species than either Holocene or modern ones. This greater diversity was, in part, due to the existence of a diverse megafauna that became extinct at the end of the Pleistocene (10 ka). However, Pleistocene small mammal guilds with extant species, especially insectivores and microtine rodents, were also more diverse. Rapid changes in small mammal species distributions, diversity patterns, and clinal shifts around 10 ka strengthens environmental models for the end-Pleistocene extinction.Modern mammal communities began to appear at the end of the Pleistocene and into the Holocene. In the eastern U.S., the species composition of these communities has been stable for the last 10 ka, although vegetational communities have shown change throughout the Holocene. In other parts of the U.S., middle Holocene warming caused some species to shift their geographic ranges. However, species composition of communities was not significantly altered. Understanding these changes not only provides a better perspective for viewing mammal communities of the past but it may also give insight into those of the future as climate will continue to vacillate, whether induced naturally or anthropogenically.
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Welc, Fabian, Khodjiakbar Toychiew, Małgorzata Suska-Malawska, Leszek Marks, and Monika Mętrak. "Paleoclimatological and Geoarchaeological Significance of the Holocene Loess – Soil Successions of the Tien Shan Foothills of Uzbekistan." Studia Quaternaria 33, no. 1 (June 1, 2016): 57–68. http://dx.doi.org/10.1515/squa-2016-0006.
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AbstractScenario of climate changes in the Late Pleistocene and Holocene in Central Asia is very fragmentary and inconsistent. Therefore, interaction between the development and decline of ancient cultures and the climate fluctuations are difficult to be traced. To resolve this problem, the key role can be played by multidisciplinary studies of unique Late Pleistocene and especially Holocene loess – soil succession of the Tien Shan foothills in Uzbekistan. This area yields unique successions of paleosols interbedded with loesses that are particularly useful for paleoclimate analysis. They are represented by continuous and uninterrupted sedimentary sequences with a highly varied record of magnetic susceptibility. As such, they contain a full sequence of short-term climatic oscillations of the Holocene in high resolution and therefore, in this case, they are exceptional on global scale. The correlation of Late Pleistocene and Holocene climate changes scenario with stages of development and collapse of the past human settlement in Central Asia seems at present one of the most promising research directions, in line with the substantial course of interdisciplinary research on the interaction between humans and the natural environment.
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Köhler, P., B. de Boer, A. S. von der Heydt, L. B. Stap, and R. S. W. van de Wal. "On the state dependency of the equilibrium climate sensitivity during the last 5 million years." Climate of the Past 11, no. 12 (December 21, 2015): 1801–23. http://dx.doi.org/10.5194/cp-11-1801-2015.
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Abstract. It is still an open question how equilibrium warming in response to increasing radiative forcing – the specific equilibrium climate sensitivity S – depends on background climate. We here present palaeodata-based evidence on the state dependency of S, by using CO2 proxy data together with a 3-D ice-sheet-model-based reconstruction of land ice albedo over the last 5 million years (Myr). We find that the land ice albedo forcing depends non-linearly on the background climate, while any non-linearity of CO2 radiative forcing depends on the CO2 data set used. This non-linearity has not, so far, been accounted for in similar approaches due to previously more simplistic approximations, in which land ice albedo radiative forcing was a linear function of sea level change. The latitudinal dependency of ice-sheet area changes is important for the non-linearity between land ice albedo and sea level. In our set-up, in which the radiative forcing of CO2 and of the land ice albedo (LI) is combined, we find a state dependence in the calculated specific equilibrium climate sensitivity, S[CO2,LI], for most of the Pleistocene (last 2.1 Myr). During Pleistocene intermediate glaciated climates and interglacial periods, S[CO2,LI] is on average ~ 45 % larger than during Pleistocene full glacial conditions. In the Pliocene part of our analysis (2.6–5 Myr BP) the CO2 data uncertainties prevent a well-supported calculation for S[CO2,LI], but our analysis suggests that during times without a large land ice area in the Northern Hemisphere (e.g. before 2.82 Myr BP), the specific equilibrium climate sensitivity, S[CO2,LI], was smaller than during interglacials of the Pleistocene. We thus find support for a previously proposed state change in the climate system with the widespread appearance of northern hemispheric ice sheets. This study points for the first time to a so far overlooked non-linearity in the land ice albedo radiative forcing, which is important for similar palaeodata-based approaches to calculate climate sensitivity. However, the implications of this study for a suggested warming under CO2 doubling are not yet entirely clear since the details of necessary corrections for other slow feedbacks are not fully known and the uncertainties that exist in the ice-sheet simulations and global temperature reconstructions are large.
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Pisareva, V. V., M. A. Faustova, I. S. Zyuganova, N. V. Karpukhina, A. L. Zakharov, E. A. Konstantinov, V. V. Semenov, and R. N. Kurbanov. "Landscape and climat changes in Eastern Europe in the early Pleistocene." Стратиграфия 27, no. 4 (June 16, 2019): 93–116. http://dx.doi.org/10.31857/s0869-592x27493-116.
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The systematization of the original and published data on the geology and paleogeography of the Late Pliocene and Early Pleistocene of Eastern Europe was carried out due to the lowering of the Quaternary lower boundary to the level of 2.6 million years ago and the inclusion of the Gelasian stage in Quaternary system. It was revealed that at the bound of the Gauss-Matuyama paleomagnetic epochs, the profound landscape and climate changes took place. The rhythmic fluctuations of the climate intensified against the background of the general trend towards cooling and aridization. Subarctic landscapes appeared during the period from 2.6 to 1.8 Ma, which corresponds to the Gelasian stage (the Praetiglian and Tiglian stages of Western Europe or the Paleopleistocene of Eastern Europe). In the Eopleistocene (1.8–0.78 Ma) and Early Neopleistocene (0.78–0.42 Ma), the climate became colder while the structure of natural zonality repeatedly underwent a complex restructuring and gradually approached to the modern one. The presence of glacial deposits was noted in Eastern Europe already in the Paleopleistocene. The traces of at least three independent glaciations were revealed in the Eopleistocene, and four glaciations were suggested for the Early Neopleistocene. Based on the data from stratotype sections, paragenetic relations between heterochronous sediments in glacial and periglacial areas were established and Early Pleistocene paleogeographic events in Eastern and Western Europe were correlated.
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Murray, Hannah, and Alastair HF Robertson. "Pliocene–Pleistocene sedimentary and geomorphologic development of the Vasilikos river catchment, S Cyprus, in relation to uplift of the Troodos ophiolite and climate-related changes." Geological Magazine 157, no. 4 (October 25, 2019): 573–602. http://dx.doi.org/10.1017/s0016756819001134.
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AbstractThe Pleistocene development of the Vasilikos River exemplifies the interaction of focused, tectonically induced surface uplift and climate-influenced changes. The resulting sediments are well exposed in Vasilikos Quarry and in the main river catchment further east. An important erosional surface incises the highest-level (oldest) fluvial conglomerates, down into Late Pliocene – Early Pleistocene open-marine mudrocks (Nicosia Formation), allowing integration with the circum-Cyprus sedimentary–geomorphic development (F1–F4 stages). To determine where the quarry deposits lie in relation to the Vasilikos river catchment, the fluvial deposits were mapped and valley profiles were constructed, revealing four main episodes, each associated with incision and distinctive fluvial deposition. Source lithology strongly influenced channel morphology, infill and adjacent slope-sediment (colluvium) composition. Palaeosols, particularly red-brown terra rossa, developed on abandoned fluvial terraces and adjacent hillslopes, especially overlying F3 surfaces. The combined evidence allows close correlation of the Vasilikos river and quarry deposits. Relatively coarse (chalky conglomerate/breccia) and fine-grained colluvium (calcareous silt – Cyprus harvara) developed especially on lower hillslopes following incision (mainly above F2 and F3 surfaces). Based on regional comparisons, overall sediment aggregation ended during the Early Pleistocene. The F1–F2 surfaces and deposits are inferred to be Middle Pleistocene, the F3 ones later Middle Pleistocene and the F4 ones near the Middle–Late Pleistocene boundary. Geomorphology and deposition were tectonically forced during strong, focused Early–Middle Pleistocene surface uplift. Coarse clastic ruff-off and palaeosol development (terra rossa) and related sediment aggradation are inferred to have increased during warm, humid periods. Late Pleistocene geomorphology and deposition were more influenced by climatic change, with semi-perennial streamflow, rapid sediment aggradation and palaeosol (terra rossa) development during warm, humid periods (interglacials). Cooler (glacial) periods enhanced fluvial-incision, sediment-bypassing and hillslope colluvial processes (e.g. frost shattering, downslope creep and mass flow) when sediment transport (bypassing) exceeded sediment supply. Neotectonic faulting affected the catchment but did not greatly affect geomorphology or sediment supply. Although climate / climate change (and eustatic sea-level change) had an important influence, tectonics is interpreted as the fundamental driver of geomorphological development and fluvial sedimentation, with implications for other areas, regionally to globally.
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Sutter, Johannes, Hubertus Fischer, Klaus Grosfeld, Nanna B. Karlsson, Thomas Kleiner, Brice Van Liefferinge, and Olaf Eisen. "Modelling the Antarctic Ice Sheet across the mid-Pleistocene transition – implications for Oldest Ice." Cryosphere 13, no. 7 (July 19, 2019): 2023–41. http://dx.doi.org/10.5194/tc-13-2023-2019.
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Abstract. The international endeavour to retrieve a continuous ice core, which spans the middle Pleistocene climate transition ca. 1.2–0.9 Myr ago, encompasses a multitude of field and model-based pre-site surveys. We expand on the current efforts to locate a suitable drilling site for the oldest Antarctic ice core by means of 3-D continental ice-sheet modelling. To this end, we present an ensemble of ice-sheet simulations spanning the last 2 Myr, employing transient boundary conditions derived from climate modelling and climate proxy records. We discuss the imprint of changing climate conditions, sea level and geothermal heat flux on the ice thickness, and basal conditions around previously identified sites with continuous records of old ice. Our modelling results show a range of configurational ice-sheet changes across the middle Pleistocene transition, suggesting a potential shift of the West Antarctic Ice Sheet to a marine-based configuration. Despite the middle Pleistocene climate reorganisation and associated ice-dynamic changes, we identify several regions conducive to conditions maintaining 1.5 Myr (million years) old ice, particularly around Dome Fuji, Dome C and Ridge B, which is in agreement with previous studies. This finding strengthens the notion that continuous records with such old ice do exist in previously identified regions, while we are also providing a dynamic continental ice-sheet context.
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Reheis, Marith. "Highest Pluvial-Lake Shorelines and Pleistocene Climate of the Western Great Basin." Quaternary Research 52, no. 2 (September 1999): 196–205. http://dx.doi.org/10.1006/qres.1999.2064.
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Shoreline altitudes of several pluvial lakes in the western Great Basin of North America record successively smaller lakes from the early to the late Pleistocene. This decrease in lake size indicates a long-term drying trend in the regional climate that is not seen in global marine oxygen-isotope records. At +70 m above its late Pleistocene shoreline, Lake Lahontan in the early middle Pleistocene submerged some basins previously thought to have been isolated. Other basins known to contain records of older pluvial lakes that exceeded late Pleistocene levels include Columbus-Fish Lake (Lake Columbus-Rennie), Kobeh-Diamond (Lakes Jonathan and Diamond), Newark, Long (Lake Hubbs), and Clover. Very high stands of some of these lakes probably triggered overflows of previously internally drained basins, adding to the size of Lake Lahontan. Simple calculations based on differences in lake area suggest that the highest levels of these pluvial lakes required a regional increase in effective moisture by a factor of 1.2 to 3 relative to late Pleistocene pluvial amounts (assuming that effective moisture is directly proportional to the hydrologic index, or lake area/tributary basin area). These previously unknown lake levels reflect significant changes in climate, tectonics, and (or) drainage-basin configurations, and could have facilitated migration of aquatic species in the Great Basin.
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Pidek, Irena Agnieszka. "Pollen-based vegetation and climate reconstruction of the Ferdynandovian sequence from Łuków (eastern Poland)." Acta Palaeobotanica 53, no. 1 (June 1, 2013): 115–38. http://dx.doi.org/10.2478/acpa-2013-0009.
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ABSTRACT Early middle Pleistocene deposits from Łukow, correlated with the Cromerian complex, represent rare bi-partite Ferdynandovian pollen sequence encompassing two interglacial warmings (F1 and F2) separated by F1/2 cooling/glaciation and related to MIS 15-13. The paper presents pollen-based palaeoecological and palaeoclimate investigations in which plant climate indicators were applied. Additionally modern pollen dataset from the Roztocze region was used to evaluate vegetation history in terms of forest communities and presence and abundance of tree taxa sensitive to air temperature and humidity. Climate changes derived from pollen data indicate strong oceanic features of the climate of the first interglacial (F1) resembling those typical for the beginning of the Eemian, followed by cooling (F 1/2) with plant communities typical of the Pleistocene steppetundra, which undoubtedly indicate strong continentality, and subsequent return of more oceanic climate (F2) with mean remperature of the warmest month exceeding 18°C. Both pollen succession and climate changes recorded in the Łukow sediments correlate well with other bi-partite successions known from eastern part of European Lowlands.
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Toucanne, Samuel. "Pleistocene Fleuve Manche palaeoriver discharges: response to glacial oscillations and climate changes." Quaternary International 279-280 (November 2012): 499. http://dx.doi.org/10.1016/j.quaint.2012.08.1707.
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Marino, Gianluca, Rainer Zahn, Martin Ziegler, Conor Purcell, Gregor Knorr, Ian R. Hall, Patrizia Ziveri, and Henry Elderfield. "Agulhas salt-leakage oscillations during abrupt climate changes of the Late Pleistocene." Paleoceanography 28, no. 3 (August 2, 2013): 599–606. http://dx.doi.org/10.1002/palo.20038.
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Zhang, Jiahua, and Zhaochen Kong. "Study on vegetation and climate changes in Beijing region since late pleistocene." Chinese Geographical Science 9, no. 3 (September 1999): 243–49. http://dx.doi.org/10.1007/s11769-999-0050-z.
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Konecky, Bronwen L., James M. Russell, Thomas C. Johnson, Erik T. Brown, Melissa A. Berke, Josef P. Werne, and Yongsong Huang. "Atmospheric circulation patterns during late Pleistocene climate changes at Lake Malawi, Africa." Earth and Planetary Science Letters 312, no. 3-4 (December 2011): 318–26. http://dx.doi.org/10.1016/j.epsl.2011.10.020.
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TAKANO, OONA M., and DAVID W. STEADMAN. "Another new species of flightless Rail (Aves: Rallidae: Rallus) from Abaco, The Bahamas." Zootaxa 4407, no. 3 (April 11, 2018): 376. http://dx.doi.org/10.11646/zootaxa.4407.3.5.
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We describe a late Pleistocene species of extinct rail, Rallus gracilipes n. sp., from Sawmill Sink blue hole on Abaco Island, Little Bahama Bank, The Bahamas. The only other extinct rail known from any Bahamian island is the smaller Rallus cyanocavi, also from late Pleistocene contexts at Sawmill Sink. No fossils of R. gracilipes or R. cyanocavi have been found in Holocene sites on Abaco; the loss of both of these species is likely to be due to changes in climate, habitat, and island area during the Pleistocene-Holocene Transition.
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Crucifix, Michel. "Oscillators and relaxation phenomena in Pleistocene climate theory." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, no. 1962 (March 13, 2012): 1140–65. http://dx.doi.org/10.1098/rsta.2011.0315.
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Ice sheets appeared in the northern hemisphere around 3 Ma (million years) ago and glacial–interglacial cycles have paced Earth's climate since then. Superimposed on these long glacial cycles comes an intricate pattern of millennial and sub-millennial variability, including Dansgaard–Oeschger and Heinrich events. There are numerous theories about these oscillations. Here, we review a number of them in order to draw a parallel between climatic concepts and dynamical system concepts, including, in particular, the relaxation oscillator, excitability, slow–fast dynamics and homoclinic orbits. Namely, almost all theories of ice ages reviewed here feature a phenomenon of synchronization between internal climate dynamics and astronomical forcing. However, these theories differ in their bifurcation structure and this has an effect on the way the ice age phenomenon could grow 3 Ma ago. All theories on rapid events reviewed here rely on the concept of a limit cycle excited by changes in the surface freshwater balance of the ocean. The article also reviews basic effects of stochastic fluctuations on these models, including the phenomenon of phase dispersion, shortening of the limit cycle and stochastic resonance. It concludes with a more personal statement about the potential for inference with simple stochastic dynamical systems in palaeoclimate science.
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Brault, M. O., L. A. Mysak, H. D. Matthews, and C. T. Simmons. "Assessing the impact of late Pleistocene megafaunal extinctions on global vegetation and climate." Climate of the Past 9, no. 4 (August 2, 2013): 1761–71. http://dx.doi.org/10.5194/cp-9-1761-2013.
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Abstract. The end of the Pleistocene was a turning point for the Earth system as climate gradually emerged from millennia of severe glaciation in the Northern Hemisphere. The deglacial climate change coincided with an unprecedented decline in many species of Pleistocene megafauna, including the near-total eradication of the woolly mammoth. Due to an herbivorous diet that presumably involved large-scale tree grazing, the mammoth extinction has been associated with the rapid expansion of dwarf deciduous trees in Siberia and Beringia, thus potentially contributing to the changing climate of the period. In this study, we use the University of Victoria Earth System Climate Model (UVic ESCM) to simulate the possible effects of these extinctions on climate during the latest deglacial period. We have explored various hypothetical scenarios of forest expansion in the northern high latitudes, quantifying the biogeophysical effects in terms of changes in surface albedo and air temperature. These scenarios include a Maximum Impact Scenario (MIS) which simulates the greatest possible post-extinction reforestation in the model, and sensitivity tests which investigate the timing of extinction, the fraction of trees grazed by mammoths, and the southern extent of mammoth habitats. We also show the results of a simulation with free atmospheric CO2-carbon cycle interactions. For the MIS, we obtained a surface albedo increase and global warming of 0.006 and 0.175 °C, respectively. Less extreme scenarios produced smaller global mean temperature changes, though local warming in some locations exceeded 0.3 °C even in the more realistic extinction scenarios. In the free CO2 simulation, the biogeophysical-induced warming was amplified by a biogeochemical effect, whereby the replacement of high-latitude tundra with shrub forest led to a release of soil carbon to the atmosphere and a small atmospheric CO2 increase. Overall, our results suggest the potential for a small, though non-trivial, effect of megafaunal extinctions on Pleistocene climate.
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Adamenko, Oleg, Yaroslav Adamenko, and Kateryna Radlovska. "GEOLOGICAL MEMORY OF STARUNJA – AS THE COURSE OF PROTECTION OF THE WORLD NATURAL HERITAGE IN CARPATHIAN REGION OF UKRAINE." Scientific Bulletin Series D : Mining, Mineral Processing, Non-Ferrous Metallurgy, Geology and Environmental Engineering 32, no. 2 (2018): 15–25. http://dx.doi.org/10.37193/sbsd.2018.2.02.
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Paleontological location of the Pleistocene fauna of hairy rhinos and mammoths near the village. Starunya Bogorodchany district of Ivano-Frankivsk region (Prykarpathian, Ukraine) is considered as a paleoclimatic rapper of global changes and a stratigraphic "bridge" linking stratigraphic patterns of the Upper Pleistocene of Western Europe and the plain territory of Ukraine. This is important for the reconstruction of global climate change and the transformation of natural and man-made geosystems.
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Skonieczny, C., D. McGee, G. Winckler, A. Bory, L. I. Bradtmiller, C. W. Kinsley, P. J. Polissar, R. De Pol-Holz, L. Rossignol, and B. Malaizé. "Monsoon-driven Saharan dust variability over the past 240,000 years." Science Advances 5, no. 1 (January 2019): eaav1887. http://dx.doi.org/10.1126/sciadv.aav1887.
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Reconstructions of past Saharan dust deposition in marine sediments provide foundational records of North African climate over time scales of 103to 106years. Previous dust records show primarily glacial-interglacial variability in the Pleistocene, in contrast to other monsoon records showing strong precessional variability. Here, we present the first Saharan dust record spanning multiple glacial cycles obtained using230Th normalization, an improved method of calculating fluxes. Contrary to previous data, our record from the West African margin demonstrates high correlation with summer insolation and limited glacial-interglacial changes, indicating coherent variability in the African monsoon belt throughout the late Pleistocene. Our results demonstrate that low-latitude Saharan dust emissions do not vary synchronously with high- and mid-latitude dust emissions, and they call into question the use of existing Plio-Pleistocene dust records to investigate links between climate and hominid evolution.
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Orain, R., V. Lebreton, E. Russo Ermolli, A. M. Sémah, S. Nomade, Q. Shao, J. J. Bahain, U. Thun Hohenstein, and C. Peretto. "Hominin responses to environmental changes during the Middle Pleistocene in central and southern Italy." Climate of the Past 9, no. 2 (March 14, 2013): 687–97. http://dx.doi.org/10.5194/cp-9-687-2013.
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Abstract. The palaeobotanical record of early Palaeolithic sites from Western Europe indicates that hominins settled in different kinds of environments. During the "mid-Pleistocene transition (MPT)", from about 1 to 0.6 Ma, the transition from 41- to 100-ka dominant climatic oscillations, occurring within a long-term cooling trend, was associated with an aridity crisis which strongly modified the ecosystems. Starting from the MPT the more favourable climate of central and southern Italy provided propitious environmental conditions for long-term human occupations even during the glacial times. In fact, the human strategy of territory occupation was certainly driven by the availabilities of resources. Prehistoric sites such as Notarchirico (ca. 680–600 ka), La Pineta (ca. 600–620 ka), Guado San Nicola (ca. 380–350 ka) or Ceprano (ca. 345–355 ka) testify to a preferential occupation of the central and southern Apennines valleys during interglacial phases, while later interglacial occupations were oriented towards the coastal plains, as attested by the numerous settlements of the Roma Basin (ca. 300 ka). Faunal remains indicate that human subsistence behaviours benefited from a diversity of exploitable ecosystems, from semi-open to closed environments. In central and southern Italy, several palynological records have already illustrated the regional- and local-scale vegetation dynamic trends. During the Middle Pleistocene climate cycles, mixed mesophytic forests developed during the interglacial periods and withdrew in response to increasing aridity during the glacial episodes. New pollen data from the Boiano Basin (Molise, Italy) attest to the evolution of vegetation and climate between MIS 13 and 9 (ca. 500 to 300 ka). In this basin the persistence of high edaphic humidity, even during the glacial phases, could have favoured the establishment of a refuge area for the arboreal flora and provided subsistence resources for the animal and hominin communities during the Middle Pleistocene. This could have constrained human groups to migrate into such a propitious area. Regarding the local climate evolution during the glacial episodes, the supposed displacement from these sites could be linked to the environmental dynamics solely due to the aridity increase, rather than directly to the global climate changes.
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Orain, R., V. Lebreton, E. Russo Ermolli, A. M. Sémah, S. Nomade, Q. Shao, J. J. Bahain, U. Thun Hohenstein, and C. Peretto. "Hominin responses to environmental changes during the Middle Pleistocene in Central and Southern Italy." Climate of the Past Discussions 8, no. 5 (October 23, 2012): 5181–207. http://dx.doi.org/10.5194/cpd-8-5181-2012.
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Abstract. The palaeobotanical record of early Palaeolithic sites from Western Europe indicates that hominins settled in different kinds of environments. During the "Mid-Pleistocene Transition (MPT)", from about 1 to 0.6 Ma, the transition from 41-ka to 100-ka dominant climatic oscillations, occurring within a long-term cooling trend, was associated with an aridity crisis which strongly modified the ecosystems. Starting from the MPT the more favorable climate of central and southern Italy provided propitious environmental conditions for long-term human occupations even during the glacial times. In fact, the human strategy of territory occupation was certainly driven by the availabilities of resources. Prehistoric sites such as Notarchirico (ca. 680–600 ka), La Pineta (ca. 600–620 ka), Gaudo San Nicola (ca. 380–350 ka) or Ceprano (ca. 345–355 ka) testify to a preferential occupation of the central and southern Apennines valleys during interglacial phases, while later interglacial occupations were oriented towards the coastal plains, as attested by the numerous settlements of the Roma basin (ca. 300 ka). Faunal remains indicate that human subsistence behaviors benefited of a diversity of exploitable ecosystems, from semi-open to closed environments. In central and southern Italy, several palynological records have already illustrated the regional and local scale vegetation dynamic trends. During the Middle Pleistocene climate cycles, mixed mesophytic forests developed during the interglacial periods and withdrew in response to increasing aridity during the glacial episodes. New pollen data from the Boiano basin (Molise, Italy), attest to the evolution of vegetation and climate between OIS 13 and 9 (ca. 500 to 300 ka). In this basin, the persistence of high edaphic humidity, even during the glacial phases, could have favored the establishment of a refuge area for the arboreal flora and provided subsistence resources for the animal and hominin communities during the Middle Pleistocene. This could have constrained human groups to migrate into such a propitious area. Regarding to the local climate evolution during the glacial episodes, the supposed displacement from these sites could be linked to the environmental dynamics solely due to the aridity increase rather than directly to the global climate changes.
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Singh, I. B. "Climate Change and Human History in Ganga Plain during Late Pleistocene-Holocene." Journal of Palaeosciences 54, no. (1-3) (December 31, 2005): 1–12. http://dx.doi.org/10.54991/jop.2005.67.
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The Ganga Plain exhibits a large variety of landforms produced essentially during last about 100 kyrs in response to base level, tectonic and climate change. Prominent changes in the monsoon rainfall in the Ganga Plain have been identified, namely, 45 kyrs BP, humid climate; 20-13 kyrs BP, low rainfall; 13-11.5 kyrs BP, high rainfall; 11.5-10.5 kyrs BP, low rainfall; 10.5-5.8 kyrs BP, high rainfall; 5.8-2.0 kyrs BP, low rainfall; and 2.0-0 kyrs BP, high rainfall. Palaeo-vegetation studies indicate that the Ganga Plain was a grassland, at least, since 45 kyrs BP, where C-4 type vegetation dominated. The lakes supported C-3 type vegetation and they show changes in the water budget in response to the changes in rainfall. There is evidence of occupation of Ganga Plain by humans, at least, since 45 kyrs. They occupied the high grounds close to the water bodies, mostly lakes and ponds. Initially human population was hunter-gatherer depending on rich fauna and wild vegetation. Frequent climate changes in latest Pleistocene-Early Holocene probably led to adaptation of agricultural practices by humans. Large-scale occupation of the Ganga Plain took place between 3.5-3.0 kyrs BP. Study of oxygen isotopes in teeth enamel show century-scale rainfall changes in the last 3.5 kyrs BP which show some correlation to the cultural changes in the Ganga Plain. Climate change and human history in the Ganga Plain is closely related and need to be studied by high-resolution investigations.
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Wan, Xinru, and Zhibin Zhang. "Climate warming and humans played different roles in triggering Late Quaternary extinctions in east and west Eurasia." Proceedings of the Royal Society B: Biological Sciences 284, no. 1851 (March 22, 2017): 20162438. http://dx.doi.org/10.1098/rspb.2016.2438.
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Climate change and humans are proposed as the two key drivers of total extinction of many large mammals in the Late Pleistocene and Early Holocene, but disentangling their relative roles remains challenging owing to a lack of quantitative evaluation of human impact and climate-driven distribution changes on the extinctions of these large mammals in a continuous temporal–spatial dimension. Here, our analyses showed that temperature change had significant effects on mammoth (genus Mammuthus ), rhinoceros (Rhinocerotidae), horse (Equidae) and deer (Cervidae). Rapid global warming was the predominant factor driving the total extinction of mammoths and rhinos in frigid zones from the Late Pleistocene and Early Holocene. Humans showed significant, negative effects on extirpations of the four mammalian taxa, and were the predominant factor causing the extinction or major extirpations of rhinos and horses. Deer survived both rapid climate warming and extensive human impacts. Our study indicates that both the current rates of warming and range shifts of species are much faster than those from the Late Pleistocene to Holocene. Our results provide new insight into the extinction of Late Quaternary megafauna by demonstrating taxon-, period- and region-specific differences in extinction drivers of climate change and human disturbances, and some implications about the extinction risk of animals by recent and ongoing climate warming.
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Pennington, R. Toby, Matt Lavin, Darién E. Prado, Colin A. Pendry, Susan K. Pell, and Charles A. Butterworth. "Historical climate change and speciation: neotropical seasonally dry forest plants show patterns of both Tertiary and Quaternary diversification." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 359, no. 1443 (March 29, 2004): 515–38. http://dx.doi.org/10.1098/rstb.2003.1435.
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Historical climate changes have had a major effect on the distribution and evolution of plant species in the neotropics. What is more controversial is whether relatively recent Pleistocene climatic changes have driven speciation, or whether neotropical species diversity is more ancient. This question is addressed using evolutionary rate analysis of sequence data of nuclear ribosomal internal transcribed spacers in diverse taxa occupying neotropical seasonally dry forests, including Ruprechtia (Polygonaceae), robinioid legumes (Fabaceae), Chaetocalyx and Nissolia (Fabaceae), and Loxopterygium (Anacardiaceae). Species diversifications in these taxa occurred both during and before the Pleistocene in Central America, but were primarily pre–Pleistocene in South America. This indicates plausibility both for models that predict tropical species diversity to be recent and that invoke a role for Pleistocene climatic change, and those that consider it ancient and implicate geological factors such as the Andean orogeny and the closure of the Panama Isthmus. Cladistic vicariance analysis was attempted to identify common factors underlying evolution in these groups. In spite of the similar Mid–Miocene to Pliocene ages of the study taxa, and their high degree of endemism in the different fragments of South American dry forests, the analysis yielded equivocal, non–robust patterns of area relationships.
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Driese, Steven G., Zheng-Hua Li, and Sally P. Horn. "Late Pleistocene and Holocene climate and geomorphic histories as interpreted from a 23,000 14C yr B.P. paleosol and floodplain soils, southeastern West Virginia, USA." Quaternary Research 63, no. 2 (March 2005): 136–49. http://dx.doi.org/10.1016/j.yqres.2004.10.005.
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Field, micromorphological, pollen, whole soil (XRF), and stable isotope geochemical methods were used to evaluate the latest Pleistocene to Holocene climate record from a floodplain–terrace system in southeastern West Virginia. A late Pleistocene (22,940 ± 150 14C yr B.P.) silt paleosol with low-chroma colors formed from fluviolacustrine sediment deposited during the last glacial maximum (Wisconsinan) and records a cooler full-glacial paleoclimate. Fluvial gravel deposited between the latest Pleistocene and earliest Holocene (prior to 6360 ± 40 14C yr B.P.) was weathered in the middle Holocene under warmer, drier climate conditions, possibly correlated with the Hypsithermal and Altithermal Events of the eastern and southwestern United States, respectively. The glacial to interglacial climate shift is recorded by: (1) changes from a poorly drained landscape with fine-textured soil, characterized by high organic C and redoximorphic features related to Fe removal and concentration, to a well-drained, coarse-textured setting without gley and with significant argillic (Bt) horizon development; (2) changes from a high Zr and Ti silt-dominated parent material to locally derived, coarse fluvial gravels lower in Zr and Ti; (3) a shift from dominantly conifer and sedge pollen in the paleosol to a modern oak/hickory hardwood assemblage; and (4) a shift in δ13C values of soil organic matter from −28‰ to −24‰ PDB, suggesting an ecosystem shift from cooler, C3-dominated flora to one that was mixed C3 and C4, but still predominantly composed of C3 plants. A root-restrictive placic horizon developed between the late Pleistocene silt paleosol and the overlying fluvial gravel because of the high permeability contrast between the two textures of soil materials. This layer formed a barrier that effectively isolated the Pleistocene paleosol from later Holocene pedogenic processes.
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Andreev, A. A., P. E. Tarasov, V. Wennrich, E. Raschke, U. Herzschuh, N. R. Nowaczyk, J. Brigham-Grette, and M. Melles. "Late Pliocene and Early Pleistocene vegetation history of northeastern Russian Arctic inferred from the Lake El'gygytgyn pollen record." Climate of the Past 10, no. 3 (May 22, 2014): 1017–39. http://dx.doi.org/10.5194/cp-10-1017-2014.
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Abstract. The 318 m thick lacustrine sediment record from Lake El'gygytgyn, northeastern Russian Arctic cored by the international El'gygytgyn Drilling Project provides unique opportunities for the time-continuous reconstruction of the regional paleoenvironmental history for the past 3.6 Myr. Pollen studies of the lower 216 m of the lacustrine sediments demonstrate their value as an excellent archive of vegetation and climate changes during the Late Pliocene and Early Pleistocene. About 3.5–3.35 Myr BP, the vegetation at Lake El'gygytgyn, now an area of tundra was dominated by spruce-larch-fir-hemlock forests. After ca. 3.35 Myr BP dark coniferous taxa gradually disappeared. A very pronounced environmental change took place ca. 3.31–3.28 Myr BP, corresponding to the Marine Isotope Stage (MIS) M2, when treeless tundra- and steppe-like habitats became dominant in the regional vegetation. Climate conditions were similar to those of Late Pleistocene cold intervals. Numerous coprophilous fungi spores identified in the pollen samples suggest the presence of grazing animals around the lake. Following the MIS M2 event, larch-pine forests with some spruce mostly dominated the area until ca. 2.6 Myr BP, interrupted by colder and drier intervals ca. 3.043–3.025, 2.935–2.912, and 2.719–2.698 Myr BP. At the beginning of the Pleistocene, ca. 2.6 Myr BP, noticeable climatic deterioration occurred. Forested habitats changed to predominantly treeless and shrubby environments, which reflect a relatively cold and dry climate. Peaks in observed green algae colonies (Botryococcus) around 2.53, 2.45, 2.32–2.305, 2.20 and 2.16–2.15 Myr BP suggest a spread of shallow water environments. A few intervals (i.e., 2.55–2.53, ca. 2.37, and 2.35–2.32 Myr BP) with a higher presence of coniferous taxa (mostly pine and larch) document some relatively short-term climate ameliorations during Early Pleistocene glacial periods.
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Andreev, A. A., P. E. Tarasov, V. Wennrich, E. Raschke, U. Herzschuh, N. R. Nowaczyk, J. Brigham-Grette, and M. Melles. "Late Pliocene and early Pleistocene environments of the north-eastern Russian Arctic inferred from the Lake El'gygytgyn pollen record." Climate of the Past Discussions 9, no. 4 (August 13, 2013): 4599–653. http://dx.doi.org/10.5194/cpd-9-4599-2013.
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Abstract. The 318 m thick lacustrine sediment record in Lake El'gygytgyn, northeastern Russian Arctic cored by the international El'gygytgyn Drilling Project provides unique opportunities allowing the time-continuous reconstruction of the regional paleoenvironmental history for the past 3.6 Myr. Pollen studies of the lower 216 m of the lacustrine sediments show their value as an excellent archive of vegetation and climate changes during the Late Pliocene and Early Pleistocene. About 3.50–3.35 Myr BP the vegetation at Lake El'gygytgyn, in nowadays tundra area, was dominated by spruce-larch-fir-hemlock forests. After ca. 3.4 Myr BP dark coniferous taxa gradually disappeared. A very pronounced environmental changes took place at ca. 3.305–3.275 Myr BP, corresponding with the Marine Isotope Stage (MIS) M2, when treeless tundra- and steppe-like habitats became dominant in the regional vegetation. Climate conditions were similar to those of Late Pleistocene cold intervals. Numerous coprophilous fungi spores identified in the pollen samples suggest the presence of grazing animals around the lake. Following the MIS M2 event, larch-pine forests with some spruce mostly dominated in the area until ca. 2.6 Myr BP, interrupted by colder and drier intervals ca. 3.04–3.02, 2.93–2.91, and 2.725–2.695 Myr BP. At the beginning of the Pleistocene, ca. 2.6 Myr BP, noticeable climatic deterioration occurred. Forested habitats changed to predominantly treeless and shrubby environments, which reflect a relatively cold and dry climate. Revealed peaks in green algae colonies (Botryococcus) around 2.53, 2.45, 2.320–2.305 and 2.175–2.150 Myr BP suggest a spread of shallow water environments. Few intervals (i.e. 2.55–2.53, ca. 2.37, and 2.35–2.32 Myr BP) with a higher presence of coniferous taxa (mostly pine and larch) document some relatively short-term climate ameliorations.
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Yanina, T. A., and V. M. Sorokin. "Ponto-Caspian basins development during MIS 5." Limnology and Freshwater Biology, no. 4 (2022): 1612–14. http://dx.doi.org/10.31951/2658-3518-2022-a-4-1612.
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Abstract. The aim of this paper is reconstruction and correlation of events within the Ponto-Caspian basin system, and the response of the systems to the global climatic changes during the MIS 5 epoch. The Pontian and Caspian basins belonged to different types of the water basins, and evolved differently in the Pleistocene responding in different ways to the climate changes. The study is based on the analysis and integration of the drilling material and data published by numerous investigators of the region who have been working on the paleogeography of the Ponto-Caspian region in the Late Pleistocene.
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Markova, Anastasia K., and Andrey Yu Puzachenko. "Small mammal fauna in Europe during the second half of the Middle Pleistocene." Fossil Imprint 73, no. 1-2 (August 15, 2017): 48–66. http://dx.doi.org/10.2478/if-2017-0002.
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Evolutionary changes in European small mammals during the second half of the Middle Pleistocene, from the Likhvin (Holsteinian, Hoxnian) Interglacial (MIS 11) to the beginning of the Mikulino (Eemian) Interglacial (MIS 5e), that is between 424 ka BP and 130 ka BP were traced. Trends in evolutionary change were documented, and East European and West European faunas were compared. An integrated analysis of available theriological, geological, and geochronological data for the second half of the Middle Pleistocene in Europe has shown marked changes in the small mammal fauna throughout the period under consideration and provided information on the climate and environments at different time intervals. Changes traceable in the Arvicolinae phyletic lines made a correlation between the West European and East European mammal localities possible. The biostratigraphic scheme of the second half of the Middle Pleistocene has been developed and maps of small mammal localities compiled.
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Perrotti, Angelina, Miranda Siedelmann, Jocelyn Lam, James Russell, and John Williams. "Does Fire Drive Quaternary Ecosystem Transformation at Lake Tulane, Florida?" Bulletin of the Florida Museum of Natural History 60, no. 2 (February 16, 2023): 103. http://dx.doi.org/10.58782/flmnh.bbxn9730.
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Ecosystems across the world are experiencing seemingly unprecedented fire activity due to changes in land use and climate. However, disentangling the drivers of fire regime intensification is difficult when climate and land use changes occur simultaneously. Thus, multi-proxy paleoecological records with evidence for climate, vegetation composition, and fire regime changes can provide valuable frameworks in which to interpret modern environmental shifts. Lake Tulane, Florida, offers an iconic record of vegetation responses to Heinrich Events and other climate variations over the last 60,000 years, but its fire history is unknown. Here we present the results of a 60,000-year fire history from Lake Tulane, Florida, based on sedimentary macro charcoal data at ca. 30-year resolution. Charcoal accumulation rates are highest in pre-32,000 year old sediments and decline toward the end of the Pleistocene. Fire activity was lowest during the period directly before the last glacial maximum (32,000 to 23,000 years ago). The end-Pleistocene record indicates on-going oscillations in fire activity from 22,000 to 10,000 years ago, but fire activity does not appear to be closely linked with pine/oak oscillations, thus indicating differential drivers of vegetation and fire change. Ultimately, the fire history at Lake Tulane is best understood in the context of other environmental factors such as millennial-scale climate variability, human influence, and megaherbivory.
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Cross, Scott L., Paul A. Baker, Geoffrey O. Seltzer, Sherilyn C. Fritz, and Robert B. Dunbar. "Late Quaternary Climate and Hydrology of Tropical South America Inferred from an Isotopic and Chemical Model of Lake Titicaca, Bolivia and Peru." Quaternary Research 56, no. 1 (July 2001): 1–9. http://dx.doi.org/10.1006/qres.2001.2244.
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AbstractA simple mass balance model provides insight into the hydrologic, isotopic, and chemical responses of Lake Titicaca to past climatic changes. Latest Pleistocene climate of the Altiplano is assumed to have been 20% wetter and 5°C colder than today, based on previous modeling. Our simulation of lacustrine change since 15,000 cal yr B.P. is forced by these modeled climate changes. The latest Pleistocene Lake Titicaca was deep, fresh, and overflowing. The latest Pleistocene riverine discharge from the lake was about 8 times greater than the modern average, sufficient to allow the expansion of the great paleolake Tauca on the central Altiplano. The lake δ18O value averaged about −13‰ SMOW (the modern value is about −4.2‰). The early Holocene decrease in precipitation caused Lake Titicaca to fall below its outlet and contributed to a rapid desiccation of paleolake Tauca. Continued evaporation caused the 100-m drop in lake level, but only a slight (1–2‰) increase (relative to modern) in δ18O of early Holocene lake waters. This Holocene lowstand level of nearly 100 m was most likely produced by a precipitation decrease, relative to modern, of about 40%. The lake was saline as recently as 2000 cal yr B.P. The timing of these hydrologic changes is in general agreement with calculated changes of insolation forcing of the South American summer monsoon.
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Jacobs, Kimberly C., Sherilyn C. Fritz, and James B. Swinehart. "Lacustrine evidence for moisture changes in the Nebraska Sand Hills during Marine Isotope Stage 3." Quaternary Research 67, no. 2 (March 2007): 246–54. http://dx.doi.org/10.1016/j.yqres.2006.12.001.
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AbstractIn the central Great Plains of North America, loess stratigraphy suggests that climate during the late Pleistocene was cold and dry. However, this record is discontinuous, and there are few other records of late-Pleistocene conditions. Cobb Basin, located on the northern edge of the Nebraska Sand Hills, contains lacustrine sediments deposited during Marine Isotope Stage 3, beginning approximately 45,000 cal yr BP and continuing for at least 10,000 yr. The lake was formed by a dune dam blockage on the ancient Niobrara River, and its deposits contain a diatom record that indicates changes through time in lake depth driven by changes in effective moisture. During the earliest stages of lake formation, the climate was arid enough to mobilize dunes and emplace dune sand into a blocking position within the Niobrara streambed. Diatom assemblages suggest that lake-level was shallow at formation, increased substantially during a wet interval, and then became shallow again, as arid conditions resumed. By about 27,000 cal yr BP the lake was filled, and a shallow ephemeral river occupied the basin.
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Yang, Xiaoping, and Louis A. Scuderi. "Hydrological and Climatic Changes in Deserts of China since the Late Pleistocene." Quaternary Research 73, no. 1 (January 2010): 1–9. http://dx.doi.org/10.1016/j.yqres.2009.10.011.
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Large areas in western China were wetlands or less arid between 40 and 30 ka, corresponding to the “Greatest Lake Period” on the adjacent Tibetan Plateau. During the last glacial maximum, some of these western Chinese deserts again experienced wetter conditions; however, at the same time the sandy lands in the eastern Chinese desert belt experienced an activation of aeolian dunes. While interpretations of the mid-Holocene environment in the deserts of China are controversial, it is quite likely that it was more humid not only in the eastern areas influenced by monsoon climate systems but also in the western deserts where moisture is currently associated with westerlies. Evaluation of lacustrine records in the lakes recharged by dryland rivers and the complex interactions of these systems, as well as other paleoenvironmental proxies such as the Artemisia/Chenopodiaceae ratio, should be interpreted with greater caution. Facing the highlighted uncertainties in our understanding of climate changes in Chinese deserts, it is hoped that this special issue will improve our knowledge considerably.
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Posmentier, E. S. "Response of an ocean-atmosphere climate model to Milankovic forcing." Nonlinear Processes in Geophysics 1, no. 1 (March 31, 1994): 26–30. http://dx.doi.org/10.5194/npg-1-26-1994.
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Abstract. There is considerable evidence in support of Milankovic's theory that variations in high-latitude summer insolation caused by Earth orbital variations are the cause of the Pleistocene ice cycles. The enigmatic discrepancy between the spectra of Milankovic forcing and of Pleistocene climate variations is believed to be resolved by the slow, nonlinear response of ice sheets to changes in solar seasonality. An experiment with a preliminary version of a 14-region atmosphere/snow/upper ocean climate model demonstrates that the response of the ocean-atmosphere system alone to Milankovic forcing is capable of driving ice cycles with the observed spectrum. This occurs because of the highly nonlinear response of both the thermal seasons and the annual mean temperature to solar seasons, which is caused in turn by the highly nonlinear feedback between temperature and snow and sea ice.
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Thom, Gregory, Alexander T. Xue, André O. Sawakuchi, Camila C. Ribas, Michael J. Hickerson, Alexandre Aleixo, and Cristina Miyaki. "Quaternary climate changes as speciation drivers in the Amazon floodplains." Science Advances 6, no. 11 (March 2020): eaax4718. http://dx.doi.org/10.1126/sciadv.aax4718.
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The role of climate as a speciation driver in the Amazon has long been discussed. Phylogeographic studies have failed to recover synchronous demographic responses across taxa, although recent evidence supports the interaction between rivers and climate in promoting speciation. Most studies, however, are biased toward upland forest organisms, while other habitats are poorly explored and could hold valuable information about major historical processes. We conducted a comparative phylogenomic analysis of floodplain forest birds to explore the effects of historical environmental changes and current connectivity on population differentiation. Our findings support a similar demographic history among species complexes, indicating that the central portion of the Amazon River basin is a suture zone for taxa isolated across the main Amazonian sub-basins. Our results also suggest that changes in the fluvial landscape induced by climate variation during the Mid- and Late Pleistocene drove population isolation, leading to diversification with subsequent secondary contact.
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Brault, M. O., L. A. Mysak, H. D. Matthews, and C. T. Simmons. "Assessing the impact of late Pleistocene megafaunal extinctions on global vegetation and climate." Climate of the Past Discussions 9, no. 1 (January 21, 2013): 435–65. http://dx.doi.org/10.5194/cpd-9-435-2013.
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Abstract. The end of the Pleistocene marked a turning point for the Earth system as climate gradually emerged from millennia of severe glaciation in the Northern Hemisphere. It is widely acknowledged that the deglacial climate change coincided with an unprecedented decline in many species of large terrestrial mammals, including the near-total eradication of the woolly mammoth. Due to an herbivorous diet that presumably involved large-scale tree grazing, the mammoth expansion would have accelerated the expansion of dwarf deciduous trees in Siberia and Beringia, thus contributing to the changing climate of the period. In this study, we use the University of Victoria Earth System Climate Model (UVic ESCM) to simulate the possible effects of megafaunal extinctions on Pleistocene climate change. We have explored various hypothetical scenarios of forest expansion in the Northern Continents, quantifying the regional and global biogeophysical effects in terms of changes in surface albedo and air temperature. In particular, we focus our attention on a Maximum Impact Scenario (MIS) which simulates the greatest possible post-extinction reforestation in the model. More realistic experiments include sensitivity tests based on the timing of extinction, the fraction of trees grazed by mammoths, and the size of mammoth habitats. We also show the results of a simulation with free (non-prescribed) atmospheric CO2. For the MIS, we obtained a surface albedo increase of 0.006, which resulted in a global warming of 0.175 °C. Less extreme scenarios produced smaller global mean temperature changes, though local warming in some locations exceeded 0.3 °C even in the more realistic extinction scenarios. In the free CO2 simulation, the biogeophysical-induced warming was amplified by a biogeochemical effect whereby the replacement of high-latitude tundra with shrub forest led to a release of soil carbon to the atmosphere and a small atmospheric CO2 increase. Overall, our results suggest the potential for a small, though non-trivial, effect of megafaunal extinctions on Pleistocene climate change.
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Pisareva, V. V., M. A. Faustova, I. S. Zyuganova, N. V. Karpukhina, A. L. Zakharov, E. A. Konstantinov, V. V. Semenov, and R. N. Kurbanov. "Changes in the Landscape and Climate of Eastern Europe in the Early Pleistocene." Stratigraphy and Geological Correlation 27, no. 4 (July 2019): 475–97. http://dx.doi.org/10.1134/s086959381904004x.
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Sosdian, S., and Y. Rosenthal. "Deep-Sea Temperature and Ice Volume Changes Across the Pliocene-Pleistocene Climate Transitions." Science 325, no. 5938 (July 16, 2009): 306–10. http://dx.doi.org/10.1126/science.1169938.
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Schulte, James A., and Franck Moreno-Roark. "Live birth among Iguanian lizards predates Pliocene–Pleistocene glaciations." Biology Letters 6, no. 2 (October 7, 2009): 216–18. http://dx.doi.org/10.1098/rsbl.2009.0707.
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Among tetrapods, viviparity is estimated to have evolved independently within Squamata (lizards and snakes) more than 100 times, most frequently in species occupying cold climate environments. Because of this relationship with cold climates, it is sometimes assumed that many origins of squamate viviparity occurred over the past 2.5–4 Myr during the Pliocene–Pleistocene glaciations; however, this hypothesis is untested. Divergence-dating analysis on a 733-species tree of Iguanian lizards recovers 20 independent lineages that have evolved viviparity, of which 13 multispecies groups derived live birth prior to glacial advances (8–66 Myr ago). These results place the transitions from egg-laying to live birth among squamates in a well-supported historical context to facilitate examination of the underlying phenotypic and genetic changes associated with this complex shift in reproduction.
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Bibi, Faysal, and Wolfgang Kiessling. "Continuous evolutionary change in Plio-Pleistocene mammals of eastern Africa." Proceedings of the National Academy of Sciences 112, no. 34 (August 10, 2015): 10623–28. http://dx.doi.org/10.1073/pnas.1504538112.
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Much debate has revolved around the question of whether the mode of evolutionary and ecological turnover in the fossil record of African mammals was continuous or pulsed, and the degree to which faunal turnover tracked changes in global climate. Here, we assembled and analyzed large specimen databases of the fossil record of eastern African Bovidae (antelopes) and Turkana Basin large mammals. Our results indicate that speciation and extinction proceeded continuously throughout the Pliocene and Pleistocene, as did increases in the relative abundance of arid-adapted bovids, and in bovid body mass. Species durations were similar among clades with different ecological attributes. Occupancy patterns were unimodal, with long and nearly symmetrical origination and extinction phases. A single origination pulse may be present at 2.0–1.75 Ma, but besides this, there is no evidence that evolutionary or ecological changes in the eastern African record tracked rapid, 100,000-y-scale changes in global climate. Rather, eastern African large mammal evolution tracked global or regional climatic trends at long (million year) time scales, while local, basin-scale changes (e.g., tectonic or hydrographic) and biotic interactions ruled at shorter timescales.