Palaeoclimate characteristics in interior Siberia of MIS 6–2: first insights from the Batagay permafrost mega-thaw slump in the Yana Highlands

Syngenetic permafrost deposits formed extensively on and around the arising Beringian subcontinent during the Late Pleistocene sea level lowstands. Syngenetic deposition implies that all material, both mineral and organic, freezes parallel to sedimentation and remains frozen until degradation of the permafrost. Permafrost is therefore a unique archive of Late Pleistocene palaeoclimate. Most studied permafrost outcrops are situated in the coastal lowlands of northeastern Siberia; inland sections are, however, scarcely available. Here, we describe the stratigraphical, cryolithological, and geochronological characteristics of a permafrost sequence near Batagay in the Siberian Yana Highlands, the interior of the Sakha Republic (Yakutia), Russia, with focus on the Late Pleistocene Yedoma ice complex (YIC). The recently formed Batagay mega-thaw slump exposes permafrost deposits to a depth of up to 80 m and gives insight into a climate record close to Verkhoyansk, which has the most severe continental climate in the Northern Hemi- sphere. Geochronological dating (optically stimulated luminescence, OSL, and 14C ages) and stratigraphic implications delivered a temporal frame from the Middle Pleistocene to the Holocene for our sedimentological interpretations and also revealed interruptions in the deposition. The sequence of lithological units indicates a succession of several distinct climate phases: a Middle Pleistocene ice complex indicates cold stage climate. Then, ice wedge growth stopped due to highly increased sedimentation rates and eventually a rise in temperature. Full interglacial climate conditions existed during accumulation of an organic-rich layer – plant macrofossils reflected open forest vegetation existing under dry conditions during Marine Isotope Stage (MIS) 5e. The Late Pleistocene YIC (MIS 4–MIS 2) suggests severe cold-stage climate conditions. No alas deposits, potentially indicating thermokarst processes, were detected at the site. A detailed comparison of the permafrost deposits exposed in the Batagay thaw slump with well-studied permafrost sequences,both coastal and inland, is made to highlight common features and differences in their formation processes and palaeo-climatic histories. Fluvial and lacustrine influence is tem-orarily common in the majority of permafrost exposures, but has to be excluded for the Batagay sequence. We interpret the characteristics of permafrost deposits at this location as a result of various climatically induced processes that are partly seasonally controlled. Nival deposition might have been dominant during winter time, whereas proluvial and aeolian deposition could have prevailed during the snowmelt period and the dry summer season

Exaptation traits for megafaunal Mutualisms as a factor in plant domestication

Megafaunal extinctions are recurring events that cause evolutionary ripples, as cascades of secondary extinctions and shifting selective pressures reshape ecosystems. Megafaunal browsers and grazers are major ecosystem engineers, they: keep woody vegetation suppressed; are nitrogen cyclers; and serve as seed dispersers. Most angiosperms possess sets of physiological traits that allow for the fixation of mutualisms with megafauna; some of these traits appear to serve as exaptation (preadaptation) features for farming. As an easily recognized example, fleshy fruits are, an exaptation to agriculture, as they evolved to recruit a non-human disperser. We hypothesize that the traits of rapid annual growth, self-compatibility, heavy investment in reproduction, high plasticity (wide reaction norms), and rapid evolvability were part of an adaptive syndrome for megafaunal seed dispersal. We review the evolutionary importance that megafauna had for crop and weed progenitors and discuss possible ramifications of their extinction on: (1) seed dispersal; (2) population dynamics; and (3) habitat loss. Humans replaced some of the ecological services that had been lost as a result of late Quaternary extinctions and drove rapid evolutionary change resulting in domestication.Introduction Lost Seed-Dispersal Services - Small-Seeded Grains and Legumes - Large Fleshy Fruiting Plants Loss of Herbivory and Disturbance Regimes Plant Domestication - Exaptation Traits Supporting Domestication Anthropogenic Ecosystem Service

Woodlands and steppes: Pleistocene vegetation in Yakutia's most continental part recorded in the Batagay permafrost sequence

© 2018 Elsevier Ltd Based on fossil organism remains including plant macrofossils, charcoal, pollen, and invertebrates preserved in syngenetic deposits of the Batagay permafrost sequence in the Siberian Yana Highlands, we reconstructed the environmental history during marine isotope stages (MIS) 6 to 2. Two fossil assemblages, exceptionally rich in plant remains, allowed for a detailed description of the palaeo-vegetation during two climate extremes of the Late Pleistocene, the onset of the last glacial maximum (LGM) and the last interglacial. In addition, altogether 41 assemblages were used to outline the vegetation history since the penultimate cold stage of MIS 6. Accordingly, meadow steppes analogue to modern communities of the phytosociological order Festucetalia lenensis formed the primary vegetation during the Saalian and Weichselian cold stages. Cold-resistant tundra-steppe communities (Carici rupestris-Kobresietea bellardii) as they occur above the treeline today were, in contrast to more northern locations, mostly lacking. During the last interglacial, open coniferous woodland similar to modern larch taiga was the primary vegetation at the site. Abundant charcoal indicates wildfire events during the last interglacial. Zoogenic disturbances of the local vegetation were indicated by the presence of ruderal plants, especially by abundant Urtica dioica, suggesting that the area was an interglacial refugium for large herbivores. Meadow steppes, which formed the primary vegetation during cold stages and provided potentially suitable pastures for herbivores, were a significant constituent of the plant cover in the Yana Highlands also under the full warm stage conditions of the last interglacial. Consequently, meadow steppes occurred in the Yana Highlands during the entire investigated timespan from MIS 6 to MIS 2 documenting a remarkable environmental stability. Thus, the proportion of meadow steppe vegetation merely shifted in response to the respectively prevailing climatic conditions. Their persistence indicates low precipitation and a relatively warm growing season throughout and beyond the late Pleistocene. The studied fossil record also proves that modern steppe occurrences in the Yana Highlands did not establish as late as in the Holocene but instead are relicts of a formerly continuous steppe belt extending from Central Siberia to Northeast Yakutia during the Pleistocene. The persistence of plants and invertebrates characteristic of meadow steppe vegetation in interior Yakutia throughout the late Quaternary indicates climatic continuity and documents the suitability of this region as a refugium also for other organisms of the Pleistocene mammoth steppe including the iconic large herbivores

When did the chicken cross the road: archaeological and molecular evidence for ancient chickens in Central Asia

The origins and dispersal of the chicken across the ancient world remains one of the most enigmatic questions regarding Eurasian domesticated animals1,2. The lack of agreement regarding the timing and center of origin is due, in large part, to issues with morphological identifications, a lack of direct dating, and poor preservation of thin bird bones. Historical sources attest to the prominence of chickens in southern Europe and southwest Asia by the last centuries BC3. Likewise, art historical depictions of chickens and anthropomorphic rooster-human chimeras are reoccurring motifs in Central Asian prehistoric and historic traditions4-6. However, when this ritually and economically significant bird spread along the trans-Eurasian exchange routes has remained a mystery. Here we show that chickens were widely raised by people at villages across southern Central Asia from the third century BC through medieval periods for their eggs and likely also meat. In this study, we present archaeological and molecular evidence for the cultivation of chickens for egg production from 12 different Central Asian archaeological sites spanning a millennium and a half. These eggshells were recovered in high abundance at all of these sites, suggesting that chickens were widely raised by people at villages across southern Central Asia from the third century BC through medieval periods and that they were an important part of the overall diet. Contrary to views that ancient peoples of Central Asia were primarily herding sheep, goat, and cattle, these data show that chicken was also important in the subsistence economy and that it was widely spread along the ancient Silk Road.Introduction - Rapid Dissemination across the Ancient World Results - Archaeological Eggshells - Peptide Mass Fingerprinting Discussion - Evidence for Non-Seasonal Egg Laying - The Rise in Symbolic and Economic Prominence of the Chicken in Central Asia Conclusion

The Batagay permafrost mega thaw slump: an environmental archive of the Late Pleistocene continental climate

Palaeoenvironmental data preserved in permafrost contribute in our understanding of climate changes and their influence on the biocenoses during the Late Quaternary. Here we present cryolithological and palaeoecological results of studies carried out on a newly described permafrost exposure near Batagay about 50 km from Verkhoyansk, Sakha Republic, Russia, the town with the most continental climate recorded in the northern hemisphere. According to Günther et al. (2015), this unique exposure is the biggest mega thaw slump measured so far with the dimensions 800 m wide and 73 m deep. Only sparse data on the exposure are so far published in few articles (Novgorodov et al., 2013; Kunitsky et al., 2013; Ashastina et al., in press; Murton et al., 2016). The site is situated in West Beringia, the Late Quaternary landmasscovered by tundra steppe and inhabited by diverse mega herbivores. We analyzed sedimentological data, plant macro- and micro-fossils together with insect remains in order to reconstruct the changes in the biome. The temporal frame for the accumulation of the sequence is provided by radiocarbon and optical stimulated luminescence dating, according to which the formation of the sequence started in the late Middle Quaternary. The features of permafrost accumulation and sedimentation give us an opportunity to propose the landscape changes responding to the climatic pulses of Pleistocene at this particular place. The shifts in vegetation from taiga to steppe associations are in a line with stadial and intersadial events. We propose a scheme of permafrost state and vegetation changes and merge it with climate variation during Late Quaternary

Результаты комплексного исследования памятника Куртеке (Восточный Памир)

The materials of most of the archaeological sites of the Eastern Pamirs are known from lifting samples. One of them is the Kurteke rock shelter, that was discovered in 1960 by V.A. Ranov. At that time at the site there were distinguished two cultural layers dated to the Neolithic-Eneolithic and Eneolithic-Bronze period. This site is also interesting because on the walls of the rock shelter , directly above the cultural layers there are rock paintings of anthropomorphic and geometric figures. Modern data have shown that the first layer associated with the settlement of the site belongs to the final Pleistocene (older than 13 thousand years ago). In the course of the new stage of the study, palynological and carpological analysis of the soil, the study of undetectable faunal remains using the ZooMS method, and the documentation of rock carvings of the site were carried out. A comprehensive interdisciplinary study of the Kurteke materials showed that the stone industry presented here is typical of the mountainous part of Central Asia; the climate during both periods of human settlement of the site was arid, and despite the presence of cereal plants, no direct indications of their domestication were found; the faunistic composition of the site is represented by taxa typical for the territory of the Eastern Pamirs today; in the rock art there are images common in the territory of Central and Central Asia in the Bronze Age.Материалы большей части археологических памятников Восточного Памира известны по подъемным сборам. Одним из трех известных на сегодняшний день многослойных стратифицированных памятников на этой территории является навес Куртеке, исследованный в 1960 г. В.А. Рановым. Тогда же были выделены два культурных слоя, датированных периодами неолита — энеолита и энеолита — эпохой бронзы. Этот памятник интересен еще и тем, что на стенах навеса непосредственно над культурными слоями присутствуют наскальные изображения, выполненные краской, — антропомофные и геометрические фигуры. Современные данные показали, что первый слой, связанный с заселением стоянки, относится к финальному плейстоцену (древнее 13 тыс. л.н.). В ходе нового этапа изучения проведены палинологический и карпологический анализ грунта, изучение неопределимых фаунистических остатков по методу ZooMS, а также документирование наскальных изображений памятника. Комплексное междисциплинарное исследование материалов Куртеке показало, что представленная здесь каменная индустрия является типичной для горной части Центральной Азии; климат в оба периода заселения стоянки человеком был засушливым, и несмотря на присутствие злаковых растений, прямых указаний на их окультуривание обнаружено не было; фаунистический состав стоянки представлен таксонами, типичными для территории Восточного Памира сегодня; в наскальном искусстве присутствуют образы, распространенные на территории Средней и Центральной Азии в эпоху бронзы.Введение - Материалы и методы исследования - Результаты и обсуждение - Семена и фрагменты семян, идентифицированные из образца «очаг 33» памятника Куртек

Woodlands and steppes: Pleistocene vegetation in Yakutia's most continental part recorded in the Batagay permafrost sequence

© 2018 Elsevier Ltd Based on fossil organism remains including plant macrofossils, charcoal, pollen, and invertebrates preserved in syngenetic deposits of the Batagay permafrost sequence in the Siberian Yana Highlands, we reconstructed the environmental history during marine isotope stages (MIS) 6 to 2. Two fossil assemblages, exceptionally rich in plant remains, allowed for a detailed description of the palaeo-vegetation during two climate extremes of the Late Pleistocene, the onset of the last glacial maximum (LGM) and the last interglacial. In addition, altogether 41 assemblages were used to outline the vegetation history since the penultimate cold stage of MIS 6. Accordingly, meadow steppes analogue to modern communities of the phytosociological order Festucetalia lenensis formed the primary vegetation during the Saalian and Weichselian cold stages. Cold-resistant tundra-steppe communities (Carici rupestris-Kobresietea bellardii) as they occur above the treeline today were, in contrast to more northern locations, mostly lacking. During the last interglacial, open coniferous woodland similar to modern larch taiga was the primary vegetation at the site. Abundant charcoal indicates wildfire events during the last interglacial. Zoogenic disturbances of the local vegetation were indicated by the presence of ruderal plants, especially by abundant Urtica dioica, suggesting that the area was an interglacial refugium for large herbivores. Meadow steppes, which formed the primary vegetation during cold stages and provided potentially suitable pastures for herbivores, were a significant constituent of the plant cover in the Yana Highlands also under the full warm stage conditions of the last interglacial. Consequently, meadow steppes occurred in the Yana Highlands during the entire investigated timespan from MIS 6 to MIS 2 documenting a remarkable environmental stability. Thus, the proportion of meadow steppe vegetation merely shifted in response to the respectively prevailing climatic conditions. Their persistence indicates low precipitation and a relatively warm growing season throughout and beyond the late Pleistocene. The studied fossil record also proves that modern steppe occurrences in the Yana Highlands did not establish as late as in the Holocene but instead are relicts of a formerly continuous steppe belt extending from Central Siberia to Northeast Yakutia during the Pleistocene. The persistence of plants and invertebrates characteristic of meadow steppe vegetation in interior Yakutia throughout the late Quaternary indicates climatic continuity and documents the suitability of this region as a refugium also for other organisms of the Pleistocene mammoth steppe including the iconic large herbivores

The last three millions of unequal spring thaws

Evidence from various climate proxies provides us with increasingly reliable proof that only in the past 10 millennia were natural systems more or less as we see them at the present (without considering human impact). Prior to 10,000 years ago, natural systems repeatedly changed under the influence of an unstable climate. This is particularly true over the last one million years. During these times, terrestrial environments were populated by a diversity of large animals that did not survive either the last dramatic climate change or the increasing power of humans. The volume of continental ice covering the land and its impact on the planet’s physiography∗ and vegetation have varied consistently. We can try to imagine extreme conditions: the very cold springtimes of the full glacials∗, and the warm springtimes of the rapid deglaciation phases, with enormous volumes of water feeding terrifying rivers. Most of this story is frozen in the ice cover of Greenland and Antarctica, the deep layers of which have been reached by human coring activities only over the past half century. Shorter cores have been drilled in high-altitude ice caps (e.g., in the Andes) that provide insight into other parts of the planet. The interpretation of the signals locked into the ice cores led to the reconstruction of climatic curves covering approximately the past 800 millennia. In addition, long sediment cores have been recovered from thousands of lakes across the globe and yielded data useful to estimate climatic trends based on pollen* records. In the past one to three million years, the continents and oceans were in roughly their present-day locations. Environmental factors, including tectonics (mountain uplift or closure of ocean gateways), interacted with the overall long-term oscillation in atmospheric carbon-dioxide concentration, which, in turn, influenced vegetation cover and ecosystem composition. Well-established glacial-interglacial∗ cycles impacted biotic dispersal∗ events at mid-to-high latitudes and determined the geographical restriction and expansion of tropical and subtropical (warm-temperate) biomes around the globe. This book chapter constitutes an imaginary field trip, presenting the reader with exemplary records of environments, plants, large mammals, and hominins impacted by cooling and warming phases, glaciations, changes in rainfall patterns, and sea level culminating in the world of today