The rugged topography of the Himalayan region has hindered large-scale human migrations, population admixture and assimilation. Such complexity in geographical structure might have facilitated the existence of several small isolated communities in this region. We have genotyped about 850,000 autosomal markers among 35 individuals belonging to the four major populations inhabiting the Himalaya and adjoining regions. In addition, we have genotyped 794 individuals belonging to 16 ethnic groups from the same region, for uniparental (mitochondrial and Y chromosomal DNA) markers. Our results in the light of various statistical analyses suggest a closer link of the Himalayan and adjoining populations to East Asia than their immediate geographical neighbours in South Asia. Allele frequency-based analyses likely support the existence of a specific ancestry component in the Himalayan and adjoining populations. The admixture time estimate suggests a recent westward migration of populations living to the East of the Himalaya. Furthermore, the uniparental marker analysis among the Himalayan and adjoining populations reveal the presence of East, Southeast and South Asian genetic signatures. Interestingly, we observed an antagonistic association of Y chromosomal haplogroups O3 and D clines with the longitudinal distance. Thus, we summarise that studying the Himalayan and adjoining populations is essential for a comprehensive reconstruction of the human evolutionary and ethnolinguistic history of eastern Eurasia.

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Kongsfjorden, an Arctic fjord is signi cantly affected by the glacier melt and Atlanti cation, both the processes driven by accelerated warming in the Arctic. This has lead to changes in primary production, carbon pool and microbial communities, especially that in the sediment. In this study, we have examined the bacterial community structure of surface (0-2 cm) and subsurface (3-9 cm) sediments of Kongsfjorden using the high throughput sequencing analysis. Results revealed that bacterial community structure of Kongsfjorden sediments were dominated by phylum Proteobacteria followed by Bacteroidetes and Epsilonbacteraeota. While α-and γ-Proteobacterial class were dominant in surface sediments; δ-Proteobacteria were found to be predominant in subsurface sediments. The bacterial community structure in the surface and subsurface sediments showed signi cant variations (p ≤ 0.05). Total organic carbon could be one of the major parameters controlling the bacterial diversity in the surface and subsurface sediments. Functional prediction analysis indicated that the bacterial community could be involved in the degradation of complex organic compounds such as glycans, glycosaminoglycans, polycyclic aromatic hydrocarbons and also in the biosynthesis of secondary metabolites. IntroductionMarine sediment depicts most complex microbial habitats on earth. Benthic bacterial communities in the ocean play a signi cant role in remineralization of organic matter (Ravenschlag et al. 2000). Marine microorganisms hydrolyse high molecular weight organic matter to su ciently small constituents for their cellular intake and also make them easily available for higher trophic levels. Bacteria and archaea are the dominant microbial communities in marine sediments. These sediment communities are impacted by several physical and chemical parameters (Nguyen and Landfald, 2015;Jorgensen et al. 2012) and can be sensitive to environmental changes and are also affected by geographic distance and ocean currents (Hamdan et al. 2013;Xiong et al. 2014). Hence microbial community composition analysis is important to understand the benthic ecosystem processes and thereby to study about the effect of climate change.Kongsfjorden, located on the northwest coast of Spitsbergen in the Svalbard Archipelago is a tide water glacial fjord in the Arctic. Atlantic water in ow as well as several glaciers in uence the water column in the Kongsfjorden (Hop et al. 2002). The fjord is now identi ed as an ideal environment to study the impacts of climate change in the Arctic, indicated by the decrease in ice cover and a rise in melting. Physical gradients of salinity and temperature induced by the glacier melting, which generate turbidity and also sedimentation along the fjord system (Hop et al. 2002;Kotwicki et al. 2004) that ultimately affects the distribution of pelagic and benthic organisms (Kotwicki et al. 2004;Piquet et al. 2014). At the head of the fjord, tidal glaciers discharge fresh water and suspended loads, which generate steep environmental gradients (W sławs...

Kongsfjorden, an Arctic fjord is significantly affected by the glacier melt and Atlantification, both the processes driven by accelerated warming in the Arctic. This has lead to changes in primary production, carbon pool and microbial communities, especially that in the sediment. In this study, we have examined the bacterial community structure of surface (0–2 cm) and subsurface (3–9 cm) sediments of Kongsfjorden using the high throughput sequencing analysis. Results revealed that bacterial community structure of Kongsfjorden sediments were dominated by phylum Proteobacteria followed by Bacteroidetes and Epsilonbacteraeota. While α- and γ- Proteobacterial class were dominant in surface sediments; δ- Proteobacteria were found to be predominant in subsurface sediments. The bacterial community structure in the surface and subsurface sediments showed significant variations (p ≤ 0.05). Total organic carbon could be one of the major parameters controlling the bacterial diversity in the surface and subsurface sediments. Functional prediction analysis indicated that the bacterial community could be involved in the degradation of complex organic compounds such as glycans, glycosaminoglycans, polycyclic aromatic hydrocarbons and also in the biosynthesis of secondary metabolites.

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