Late Pleistocene Climate Change Research Articles

Late Quaternary glacial history of the Ulugh Muztagh, central Kunlun Mountains

Only a few studies of Quaternary glaciation have been conducted in the central Kunlun Mountains, hindering a full understanding of Late Pleistocene and Holocene climatic changes on the Tibetan Plateau. This study presents 30 new 10Be surface exposure ages from five moraine crests, two moraine platforms and two glaciofluvial terraces on the northwestern slopes of the Ulugh Muztagh in the central Kunlun Mountains. The moraine ages indicate that an old glacial advance occurred no later than ∼87.10 ka, an extensive glacial advance at ∼35.61 ka and Holocene advances at ∼7.61 ka, ∼1.65 ka, ∼0.69 ka, and ∼ 0.36 ka. Two glaciofluvial terraces were tentatively determined to have been deposited at ∼24.87 ka and ∼ 17.35 ka, possibly implying the occurrence of limited global Last Glacial Maximum (LGM) and Heinrich Stadial 1 glacial advances. After combining these findings with geomorphic evidence, it was inferred that glacial coverage was more extensive during MIS 3 than the global LGM, indicating that the timing of the LGM in the Ulugh Muztagh was asynchronous with that of the monsoon-dominated Tibetan Plateau. Reference to other palaeoclimatic archives suggested that glacial advances since MIS 3 were most likely driven by a combination of cool to cold temperatures and a relatively humid climate. The limited global LGM advance was attributed to increased aridity.

Deep mitochondrial phylogeographical pattern: cryptic population structure within an ecological niche in the near-threatened Himalayan vulture (Gyps himalayensis)

Abstract The Himalayan vulture (Gyps himalayensis) has higher environmental specificity than other species in the same genus, and its population has declined due to diclofenac exposure and shortage of carcasses as a food source. Previous analysis of mitochondrial (mt) DNA cytochrome b (Cyt b) sequences reported no distinct geographical population structure in the Himalayan vulture. Contradictory results were obtained in the present study, which investigated the population structure of 14 Himalayan vultures that migrated to Thailand during winter. Using samples obtained between 2010 and 2021, as well as limited GenBank samples, the study found that the Cyt b locus was incapable of distinguishing population structure. This dataset contrasted with the mtDNA control region (CR) and Cyt b + CR dataset, which divided them into two groups, as explained by the Middle–Late Pleistocene climate change scenario. The species split into populations from the central, western, and northern regions of its distribution range within the highland vulture ecological niche. This study reviews the different methods used as compared with previous proposals for defining guidelines for the conservation of this near-threatened scavenging species.

Late Pleistocene spore-pollen record and climatic change at the Chongphadae Cave Site, Democratic People's Republic of Korea

We present a detailed pollen record and interpretations of late Pleistocene climatic change at the Chongphadae Cave Site, Democratic People's Republic of Korea. The mean annual paleotemperature and mean annual paleoprecipitation of the site were calculated using the temperature index and precipitation index based on ecological features and geographical distribution of each taxon. Temperature index and precipitation index range from 8.8 °C to 10.4 °C and from 805.0 mm to 963.1 mm, respectively. Four dates (radiocarbon, uranium series, fission track, and paleomagnetic excursion dating) of the deposit profile investigated yield a range of ∼21.3 ka BP to ∼117 ka BP, geochronologically corresponding to the late Pleistocene, and extend from the last interglacial highstand through the Last Glacial Maximum. Our results are thus consistent with the climatic shift from interglacial to glacial conditions, provide evidence that the environments of the region, which was reconstructed from the paleoclimatic index, changed from a mild and humid to a cool and dry climate during the late Pleistocene, and suggest trends similar to those of several parts of the Northern Hemisphere which lie in the same latitudinal zone as our study area.

Drainage integration of small endorheic basins at the Pleistocene-Holocene transition: An example from southern Italy

The drainage integration of three Late Pleistocene intramontane basins located in the southern Italian Apennines was reconstructed by integrating information derived from geomorphic, structural, and stratigraphic analyses. The Santaloja (SLJ), Lago (LG), and Pantani (PN) basins are located in the axial zone of the Apennines fold-and-thrust belt where they mainly comprise Mesozoic to Cenozoic deep-sea water siliceous and calcareous rocks. The Quaternary development of these intramontane basins draining the Basento River catchment provides an example of drainage evolution within collisional mountain belts and its tectonic and climatic controlling mechanisms. Tectonically, sets of NW-SE- and NE-SW-trending faults formed a large trough with ensuing river valley development configured to synclinal folds. The ongoing interplay of these active and passive tectonic controls lead to compartmentalisation into three endorheic basins. Uncalibrated radiocarbon dating of peat layers from boreholes reveals that lacustrine facies conditions prevailed during the Late Pleistocene, spanning 34,785 to 41,325 ka during Marine Isotope Stage 3. Morphometric analysis suggests that these endorheic lacustrine basins subsequently became integrated via overspill from 13.25 kyr calBC onwards linked to Late Pleistocene climatic changes creating the Basento River. Within the axial zone of the southern Apennines, tectonically driven headwards erosion is commonly attributed to lengthening of major rivers like the Basento River. However, this study demonstrates a more complex interplay between tectonics and climate change for intramontane basin development and its drainage evolution.

Spatial differentiation of background matching strategies along a Late Pleistocene range expansion route

Late Pleistocene climate changes have deeply impacted the range dynamics of temperate species. While the genetic legacy of these dynamics has been widely investigated, little is known about their phenotypic consequences. Anti-predatory strategies offer intriguing opportunities to study phenotypic evolution in response to dispersal dynamics since the ability to avoid predation can be pivotal for populations colonising new environments. Here we investigated the spatial differentiation of background colour matching strategies along a Late Pleistocene range expansion route of a temperate species, the Tyrrhenian tree frog Hyla sarda. Using common-garden experiments, we tested whether individuals from the source area (Sardinia) and individuals from the newly founded area (Corsica) differ in two components of the camouflage strategy: colour change abilities and background choice behaviour. We found a remarkable spatial structure in both colour change abilities and background choice behaviour, across the expansion range. Tree frogs from the source area displayed higher colour change abilities and a more pronounced preference for a greener background, with respect to tree frogs from the newly colonised area. Our results support the intriguing hypothesis that Late Pleistocene biogeographic history might be an overlooked major player in shaping current spatial patterns of phenotypic traits variation across animal populations.

Population dynamics and demographic history of Eurasian collared lemmings

BackgroundAncient DNA studies suggest that Late Pleistocene climatic changes had a significant effect on population dynamics in Arctic species. The Eurasian collared lemming (Dicrostonyx torquatus) is a keystone species in the Arctic ecosystem. Earlier studies have indicated that past climatic fluctuations were important drivers of past population dynamics in this species.ResultsHere, we analysed 59 ancient and 54 modern mitogenomes from across Eurasia, along with one modern nuclear genome. Our results suggest population growth and genetic diversification during the early Late Pleistocene, implying that collared lemmings may have experienced a genetic bottleneck during the warm Eemian interglacial. Furthermore, we find multiple temporally structured mitogenome clades during the Late Pleistocene, consistent with earlier results suggesting a dynamic late glacial population history. Finally, we identify a population in northeastern Siberia that maintained genetic diversity and a constant population size at the end of the Pleistocene, suggesting suitable conditions for collared lemmings in this region during the increasing temperatures associated with the onset of the Holocene.ConclusionsThis study highlights an influence of past warming, in particular the Eemian interglacial, on the evolutionary history of the collared lemming, along with spatiotemporal population structuring throughout the Late Pleistocene.

A novel lineage of the Capra genus discovered in the Taurus Mountains of Turkey using ancient genomics.

Direkli Cave, located in the Taurus Mountains of southern Turkey, was occupied by Late Epipaleolithic hunters-gatherers for the seasonal hunting and processing of game including large numbers of wild goats. We report genomic data from new and published Capra specimens from Direkli Cave and, supplemented with historic genomes from multiple Capra species, find a novel lineage best represented by a ~14,000 year old 2.59 X genome sequenced from specimen Direkli4. This newly discovered Capra lineage is a sister clade to the Caucasian tur species (Capra cylindricornis and Capra caucasica), both now limited to the Caucasus region. We identify genomic regions introgressed in domestic goats with high affinity to Direkli4, and find that West Eurasian domestic goats in the past, but not those today, appear enriched for Direkli4-specific alleles at a genome-wide level. This forgotten 'Taurasian tur' likely survived Late Pleistocene climatic change in a Taurus Mountain refuge and its genomic fate is unknown.

Contemporary genetic structure of Xantus's Hummingbird (Basilinna xantusii) in the Baja California peninsula

Genetic structure and phylogeographic patterns of natural populations are of great importance in assessing the conservation status of species. These population properties can be estimated using molecular markers of either mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) to understand the historical, ecological and dispersal patterns that influence genetic exchange within and between populations. Basilinna xantusii is a sexually dimorphic hummingbird endemic to the Baja California Peninsula (BCP). It comprises three ancestral mitochondrial lineages linked to vicariant events, late Pleistocene climate changes and the geographical distribution of oases. This study aimed to determine and understand the current population genetic structure of this hummingbird. The genotypes of 16 microsatellite loci from 100 individuals collected across the geographical range of this species were compared with mtDNA sequences previously published. Cluster analyses identified five populations, two with almost no genetic admixture in the northern part of the BCP and three others with varying levels of admixed ancestry across the BCP. In San José de Magdalena, at the northernmost end of the range of Xantus's Hummingbird, 40% of individuals collected belong to one genetic cluster and the remaining 60% to another, both genetic clusters showing very little admixed ancestry. We hypothesize that, despite being in sympatry, these individuals do not interbreed, unlike the other populations where individuals showed ancestry coefficients of the other genetic groups. The philopatric behaviour of males and the long‐range dispersal capacity of females probably determine the observed genetic differentiation pattern. The mito‐nuclear discordance detected could be due to the molecular markers used and to female‐biased dispersal. Gene flow is asymmetric in this species, being greater from north to south than vice versa, which is probably related to differences in the seasonality of precipitation across the BCP and to urbanization of the oases.

Revisiting Late Pleistocene Loess–Paleosol Sequences in the Azov Sea Region of Russia: Chronostratigraphy and Paleoenvironmental Record

Loess-paleosol sequences are the most intensively studied terrestrial archives used for the reconstruction of Late Pleistocene environmental and climatic changes in the Azov Sea region, southwest Russia. Here we present a refined chronostratigraphy and a multiproxy record of Late Pleistocene environmental dynamics of the most complete and representative loess–paleosol sequences (Beglitsa and Chumbur-Kosa sections) from the Azov Sea region. We propose a new chronostratigraphy following the Chinese and Danubean loess stratigraphic models that refines the subdivision of the Last Interglacial paleosol (S1) complex in two Azov Sea sites, resolve the uncertainty of the stratigraphic position of the weakly developed paleosol (L1SSm) in Beglitsa section, and allow for direct correlation of the Azov Sea sections with those in the Danube Basin and the Chinese Loess Plateau. More importantly, it may serve as a basis for better constraining local and regional chronostratigraphic correlations, and facilitate the interpretation of climatic connections and possible forcing mechanisms responsible for the climatic trends in the region. In addition, a general succession of environmental dynamics is reconstructed from these two vital sections, which is broadly consistent with other loess records in the Dnieper Lowland and Lower Danube Basin, demonstrating similar climatic trends at Glacial–Interglacial time scales. Furthermore, our results have important implications for the chronostratigraphic representativeness of Beglitsa as a key regional loess section and for the reconstruction of the temporal and spatial evolution of Late Pleistocene climate in the Azov Sea region.

14,000-year Carbon Accumulation Dynamics in a Siberian Lake Reveal Catchment and Lake Productivity Changes

A multi-proxy paleolimnological analysis of a sediment core sequence from Lake Malaya Chabyda in Central Yakutia (Eastern Siberia, Russia) was conducted to investigate changes in lake processes, including lake development, sediment and organic carbon accumulation, and changes in primary productivity, within the context of Late Pleistocene and Holocene climate change. Age-depth modeling with 14C indicates that the maximum age of the sediment core is ∼14 cal kBP. Three distinct sedimentary units were identified within the sediment core. Sedimentological and biogeochemical properties in the deepest section of the core (663–584 cm; 14.1–12.3 cal kBP) suggests a lake environment mostly influenced by terrestrial vegetation, where organic carbon accumulation might have been relatively low (average ∼100 g OC m−2 a−1), although much higher than the global modern average. The middle section of the core (584–376 cm; 12.3–9.0 cal kBP) is characterized by higher primary productivity in the lake, much higher sedimentation, and a remarkable increase in OC delivery (average ∼300 g OC m−2 a−1). Conditions in the upper section of the core (<376 cm; < 9.0 cal kBP) suggest high primary productivity in the lake and high OC accumulation rates (average ∼200 g OC m−2 a−1), with stable environmental conditions. The transition from organic-poor and mostly terrestrial vegetation inputs (TOC/TNatomic ratios ∼20) to conditions dominated by aquatic primary productivity (TOC/TNatomic ratios <15) occurs at around 12.3 cal kBP. This resulted in an increase in the sedimentation rate of OC within the lake, illustrated by higher sedimentation rates and very high total OC concentrations (>30%) measured in the upper section of the core. Compact lake morphology and high sedimentation rates likely resulted in this lake acting as a significant OC sink since the Pleistocene-Holocene transition. Sediment accumulation rates declined after ∼8 cal k BP, however total OC concentrations were still notably high. TOC/TNatomic and isotopic data (δ13C) confirm the transition from terrestrial-influenced to aquatic-dominated conditions during the Early Holocene. Since the mid-Holocene, there was likely higher photosynthetic uptake of CO2 by algae, as suggested by heavier (isotopically enriched) δ13C values (>−25‰).

Neanderthal palaeoecology in the late Middle Palaeolithic of western Iberia: a stable isotope analysis of ungulate teeth from Lapa do Picareiro (Portugal)

ABSTRACTAdaptation to Late Pleistocene climate change is an oft‐cited potential contributor to Neanderthal disappearance in Eurasia. Accordingly, research on Neanderthal behaviour – including subsistence strategies, mobility, lithic technology, raw material procurement and demography – often focuses on linking changes observable in the archaeological record to specific phases of climate and environmental change. However, these correspondences are often tenuous because palaeoclimatic and archaeological records are rarely available on the same scale. In Iberia, a critical location for understanding the demise of Neanderthals, some research indicates that Neanderthal populations were unable to recover from environmental degradations known as Heinrich Events, while other studies suggest that enclaves of Neanderthal populations survived for several millennia longer in refugial zones. Here, we present a palaeoenvironmental reconstruction study using analysis of δ13C and δ18O of herbivore tooth enamel recovered from two Mousterian deposits at Lapa do Picareiro, a site located in Portuguese Estremadura. We then use these data, combined with other site‐based palaeoenvironmental indicators, to assess whether central Portugal acted as a refugium during periods of unfavourable climate, and to test whether Neanderthals in Portuguese Estremadura reorganised their mobility strategies after severe climate episodes.

Nonuniform Late Pleistocene glacier fluctuations in tropical Eastern Africa

Today's ice caps and glaciers in Africa are restricted to the highest peaks, but during the Pleistocene, several mountains on the continent were extensively glaciated. However, little is known about regional differences in the timing and extent of past glaciations and the impact of paleoclimatic changes on the afro-alpine environment and settlement history. Here, we present a glacial chronology for the Ethiopian Highlands in comparison with other East African Mountains. In the Ethiopian Highlands, glaciers reached their maximum 42 to 28 thousand years ago before the global Last Glacial Maximum. The local maximum was accompanied by a temperature depression of 4.4° to 6.0°C and a ~700-m downward shift of the afro-alpine vegetation belt, reshaping the human and natural habitats. The chronological comparison reveals that glaciers in Eastern Africa responded in a nonuniform way to past climatic changes, indicating a regionally varying influence of precipitation, temperature, and orography on paleoglacier dynamics.

Late Pleistocene lake level, glaciation and climate change in the Mongolian Altai deduced from sedimentological and palynological archives

AbstractGlacial and lacustrine sediments from the Mongolian Altai provide paleoclimatic information for the late Pleistocene in Mongolia, for which only a few sufficiently studied archives exist. Glacial stages referred to global cooling events are reported for the last glacial maximum (27–21 ka) and the late glacial period (18–16 ka). Sedimentary archives from the first part of the last glacial period are infrequent. We present proxy data for this period from two different archives (88–63 and 57–30 ka). Due to the limitation of effective moisture, an increase of precipitation is discussed as one trigger for glacier development in the cold-arid regions of central Asia. Our pollen analysis from periods of high paleolake levels in small catchments indicate that the vegetation was sparse and of dry desert type between 42–29 and 17–11 ka. This apparent contradiction between high lake levels and dry landscape conditions, the latter supported by intensified eolian processes, points to lower temperatures and cooler conditions causing reduced evaporation to be the main trigger for the high lake levels during glacier advances. Rising temperatures that cause melting of glacier and permafrost ice and geomorphological processes play a role in paleolake conditions. Interpreting lake-level changes as regional or global paleoclimate signals requires detailed investigation of geomorphological settings and mountain–basin relationships.

Rapid range shifts and megafaunal extinctions associated with late Pleistocene climate change

Large-scale changes in global climate at the end of the Pleistocene significantly impacted ecosystems across North America. However, the pace and scale of biotic turnover in response to both the Younger Dryas cold period and subsequent Holocene rapid warming have been challenging to assess because of the scarcity of well dated fossil and pollen records that covers this period. Here we present an ancient DNA record from Hall’s Cave, Texas, that documents 100 vertebrate and 45 plant taxa from bulk fossils and sediment. We show that local plant and animal diversity dropped markedly during Younger Dryas cooling, but while plant diversity recovered in the early Holocene, animal diversity did not. Instead, five extant and nine extinct large bodied animals disappeared from the region at the end of the Pleistocene. Our findings suggest that climate change affected the local ecosystem in Texas over the Pleistocene-Holocene boundary, but climate change on its own may not explain the disappearance of the megafauna at the end of the Pleistocene.

Rapid Late Pleistocene climate change reconstructed from a lacustrine ostracod record in central Italy (Lake Trasimeno, Umbria)

This study presents, for the first time, a detailed quantitative reconstruction of winter (January) and summer (July) palaeotemperatures from the Late Pleistocene to Holocene transition in central Italy based on ostracod assemblages in an 8.59‐m‐long sediment core retrieved in Lake Trasimeno. Of 19 ostracod species recovered, 13 were calibrated according to their living temperature ranges, enabling us to reconstruct mean January and July temperature ranges using the mutual ostracod temperature range (MOTR) method. The occurrences of Cytheromorpha fuscata and Limnocythere suessenbornensis from 44 000 to 25 500 cal. a BP showed mean January temperatures at least 7 °C colder and mean July temperature at least 1 °C cooler in some intervals compared to present‐day temperatures. Comparison of the MOTR‐derived January minima curve with a Greenland oxygen isotope record (NGRIP) shows a remarkable correlation of warmer Greenland Interstadial and the colder Greenland Stadial events with clear peaks and troughs in the MOTR signal. These correlations were tested successfully by tuning the MOTR curve to the NGRIP record, resulting in an improved age‐depth model combining radiocarbon ages with MOTR tie points. The results demonstrate that a record of rapid climate change in the North Atlantic region is archived in lacustrine ostracod assemblages in central Italy.

Late Pleistocene and Early Holocene climate changes and human habitation in the arctic Western Beringia based on revision of palaeobotanical data

Paleoenvironmental and paleoclimatic changes at the transition from the Late Pleistocene to the Early Holocene in the arctic Western Beringia (AWB) appear to be extremely important for human habitation record of the area. To estimate that we used multiple paleoenvironmental proxy-data collected from different locations (n = 30) and archaeological data from radiocarbon-dated sites (n = 36). Based on correlations between pollen records and their radiocarbon chronology we combined paleoenvironmental data into single generalized sequence for the entire AWB compared to global temperature trend and placed archaeological data on the same time scale. General trend of paleoclimatic changes in the second half of Late Pleistocene is explored, in which the sequence of major climate changes within Marine Isotope Stages 3 and 2, and in the beginning of the Holocene are revealed. Climate changes and landscape evolution play as a key governing factor for the human population of the area since its initial phase. Human habitation is documented starting ca. 50,000 BP. Since then, AWB remains human populated but witnessed a number of cultural changes and intrusions before the present-day map of ethnic groups became finally formed. Repeated arrival of new population into AWB finds strong correlation with major paleogeographic events, both cold and warm, such as Last Glacial Maximum, Younger Dryas, and the onset of the Holocene. It is shown that human habitation had been consistently driven by various abiotic and biotic factors, that is, by complex interpaly of development in plant and faunistic associations, landscape evolution, tree line change, and climate-driven changes in spatiotemporal patterns of population dynamics in megaherbivores, especially mammoth.

Late Pliocene and early Pleistocene vegetation and climate change revealed by a pollen record from Nihewan Basin, North China

The Nihewan Formation is an important early Quaternary sedimentary formation in North China. We conducted pollen analyses of 183 samples and 1611 modern surface samples to characterize the processes of vegetation succession and climate change during the Pliocene-Pleistocene transition (2.89–2.34 Ma) in the Nihewan Basin. The results show that pollen assemblages are dominated by arboreal pollen, indicating that the vegetation in the study area was forest dominated and that the climate was more humid than today, however, the temperature varied substantially. The most substantial vegetation and climate changes occurred at ∼2.8 Ma, when the pollen representation of warm and humid tolerant taxa such as evergreen Quercus and Carya disappeared, and also broadleaved deciduous types such as Ulmus, deciduous Quercus and Betula decreased obviously, on the contrary, the pollen representation of cold and drought tolerant taxa increased substantially: e.g. Picea (from generally less than 20% to more than 30%) and Chenopodiaceae (from generally less than 10% to more than 20%). The quantitative reconstructed results indicating that Tann decreased by about 2–3 °C and Pann decreased by ∼150 mm compared to before 2.8 Ma, with a maximum decrease of ∼9 °C for Tann and ∼450 mm for Pann. Another important vegetation and climate changes occurred at ∼2.6 Ma, which was the coldest and driest of the studied interval, when the vegetation was substantially simplified with spruce (generally above 80%) as the dominated types.

Late Pleistocene climate change and population dynamics of Japanese Myodes voles inferred from mitochondrial cytochrome b sequences

The Japanese archipelago is comprised of four main islands—Hokkaido, Honshu, Shikoku, and Kyushu—which contain high mountainous areas that likely allowed for lineage differentiation and population genetic structuring during the climatic changes of the late Pleistocene. Here, we assess the historical background of the evolutionary dynamics of herbivorous red-backed voles (Myodes) in Japan, examining the evolutionary trends of mitochondrial cytochrome b gene (Cytb) sequence variation. Four apparent signals from rapid expansion events were detected in three species, M. rufocanus and M. rutilus from Hokkaido and M. smithii from central Honshu. Taken together with results from previous studies on Japanese wood mice (Apodemus spp.), three of the expansion events were considered to be associated with predicted bottleneck events at the marine isotope stage (MIS) 4 period, in which glaciers are thought to have expanded extensively, especially at higher elevations. In the late Pleistocene, the possible candidates are transitions MIS 6/5, MIS 4/3, and MIS 2/1, which can be characterized by the cold periods of the penultimate glacial maximum, MIS 4, and the last glacial maximum, respectively. Our data further reveal the genetic footprints of repeated range expansion and contraction in the northern and southern lineages of the vole species currently found in central Honshu, namely M. andersoni and M. smithii, in response to climatic oscillation during the late Pleistocene. The time-dependent evolutionary rates of the mitochondrial Cytb presented here would provide a possible way for assessing population dynamics of cricetid rodents responding to the late Pleistocene environmental fluctuation.

Late Pleistocene climate change shapes population divergence of an Atlantic Forest passerine: a model-based phylogeographic hypothesis test

Several evolutionary processes seem to have influenced the Atlantic Forest (AF) biogeographic history, as suggested by phylogeographic studies that have shown a multitude of patterns. Here, we use approximate Bayesian computation to test alternative historical hypotheses to investigate the phylogeographic pattern, historical demography, and palaeodistribution of the Grey-hooded Flycatcher Mionectes rufiventris, an endemic AF bird, distributed mainly in southern areas of the biome. Our goal was to integrate molecular and ecological data to test diversification hypotheses available for the AF. Our investigation revealed two mitochondrial phylogroups, geographically structured around the Doce River. Coalescence analyses revealed that these groups shared a common ancestor in the Late Pleistocene, between 200,000 and 300,000 years ago, and that divergence was probably associated with climatic fluctuations during this period. Demographic analyses suggested recent demographic expansion in both groups. Ecological niche modelling suggested larger ranges during the Last Glacial Maximum (LGM) than in the present, not in agreement with the genetic pattern recovered. We simulated alternative historical models to test these competing scenarios. Our findings support the existence of small populations during the LGM which expanded afterwards from putative refuges. Thus, these results suggest that the Pleistocene climate shaped patterns of diversification and demographic history of this species in accordance with the classical forest refuge hypothesis.

Late Pleistocene climatic changes promoted demographic expansion and population reconnection of a Neotropical savanna-adapted bird, Neothraupis fasciata (Aves: Thraupidae).

We performed phylogeographic and genetic structure analyses of Neothraupis fasciata joined with species distribution modelling to evaluate whether: (1) the distribution of genetic variability shows a pattern expected by the isolation-by-distance model; (2) the influence of the Pleistocene climate changes on species distribution; and (3) climate/climatic stability (hypothesis of climatic stability) as a predictor of population genetic diversity. Based on two molecular datasets (ND2 and FIB-5), the isolation-by-distance hypothesis was not supported. The mitochondrial haplotype network indicated the existence of historically isolated populations at the southern range of the species distribution, and recent population expansion was identified by both neutrality tests and extended Bayesian skyline plot analysis. Thus, the climatic changes during the Pleistocene might have promoted the reconnection of the partially isolated southern populations, which may have persisted in the plateaus during the cycles of savanna contractions. Subsequently, this species (re)colonized northern areas of the species present distribution, following the continuous vegetation on the São Francisco and Central plateaus about 60 kyr, and also reached the Amazonian savannas likely via the central corridor. Thus, our results indicated that the intrinsic relationship between the relief heterogeneity (plateaus and depressions) and the climatic fluctuations, mainly in the Pleistocene, promoted population reconnection and demographic expansion of N. fasciata.