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Biology subjects

Kolar, J.

Publications and source records attributed to Kolar, J..

3 recordsLinked to original sources

Cultural affiliation accounts for most of the spatiotemporal variation in burial rite practices

Describing and interpreting spatiotemporal patterns in human culture has been a central focus of anthropology and archaeology for over a century. Recent ethnographic studies have highlighted the complexity of the processes generating these patterns, including isolation-by-distance, homophily, and common descent. However, investigating these processes in prehistoric archaeology remains challenging. Here we make use of a new interdisciplinary database and a combined dataset of ancient DNA (aDNA) genomic sequences to analyse the relationship between spatiotemporal patterns in cultural and genomic variation, by testing whether broadly defined clusters of genomic affinities correspond to spatiotemporal changes in burial rites, while controlling for other factors, using a Gaussian process model. We use data from the Big Interdisciplinary Archaeological Database (BIAD), linking mortuary information from [~]4,200 individuals with genetic ancestry and mobility data inferred from over 1,300 human genomes, from Western Eurasia [~]10,000-2000 BP. By integrating and modelling these diverse datasets, we aim to provide a detailed understanding of how genomic history intersects with cultural evolution, offering new insights into the dynamics behind these complex processes, and the extent to which genes and culture are transmitted in parallel. In the case of burial orientation, we found that cultural affiliation was the main factor accounting for variation with little to no role for ancestry, while for body position the picture was more mixed but cultural affiliation also played an important role.

genetics↗

Generalist vs specialist strategy shapes microbiomes in blood feeding parasite Polyplax serrata.

Insects live in association with bacterial communities, collectively referred to as the microbiome. Microbiome composition varies widely across insect taxa and is shaped by multiple factors, including host phylogeny, environmental conditions, geographic distribution, and nutritional ecology. One hypothesis is that microbiome composition may also reflect whether the host adopts a generalist or specialist ecological strategy. We tested this hypothesis using the sucking louse Polyplax serrata, which offers several advantages as a model system. First, as permanent ectoparasites, lice inhabit a relatively stable and simplified environment, thereby minimizing potential confounding variables. Second, within P. serrata, two closely related lineages have been identified: one restricted to a single rodent host (Apodemus flavicollis), and the other exploiting two hosts (A. flavicollis and A. sylvaticus). We analyzed and compared microbiome structure in these two lineages using 16S rRNA gene amplicon sequencing. While alpha diversity did not differ between the lineages, beta diversity differed significantly, particularly in pairwise dissimilarities among individual samples. These results suggest that in P. serrata, host specialization strategy influences microbiome diversity, with the "generalist" lineage harboring more heterogeneous communities. This finding extends previous observations on ecological divergence between the two lineages, showing that closely related cryptic species with highly similar genomes, living sympatrically in the same environment, can rapidly evolve distinct life strategies that, in turn, shape both their genetic structure and their microbiomes.

evolutionary biology↗

An integrative skeletal and paleogenomic analysis of prehistoric stature variation suggests relatively reduced health for early European farmers

Human culture, biology, and health were shaped dramatically by the onset of agriculture ~12,000 years before present (BP). Subsistence shifts from hunting and gathering to agriculture are hypothesized to have resulted in increased individual fitness and population growth as evidenced by archaeological and population genomic data alongside a simultaneous decline in physiological health as inferred from paleopathological analyses and stature reconstructions of skeletal remains. A key component of the health decline inference is that relatively shorter statures observed for early farmers may (at least partly) reflect higher childhood disease burdens and poorer nutrition. However, while such stresses can indeed result in growth stunting, height is also highly heritable, and substantial inter-individual variation in the height genetic component within a population is typical. Moreover, extensive migration and gene flow were characteristics of multiple agricultural transitions worldwide. Here, we consider both osteological and ancient DNA data from the same prehistoric individuals to comprehensively study the trajectory of human stature variation as a proxy for health across a transition to agriculture. Specifically, we compared predicted genetic contributions to height from paleogenomic data and achieved adult osteological height estimated from long bone measurements on a per-individual basis for n=160 ancient Europeans from sites spanning the Upper Paleolithic to the Iron Age (~38,000-2,400 BP). We found that individuals from the Neolithic were shorter than expected (given their individual polygenic height scores) by an average of -4.47 cm relative to individuals from the Upper Paleolithic and Mesolithic (P=0.016). The average osteological vs. expected stature then increased relative to the Neolithic over the Copper (+2.67 cm, P=0.052), Bronze (+3.33 cm, P=0.032), and Iron Ages (+3.95 cm, P=0.094). These results were partly attenuated when we accounted for genome-wide genetic ancestry variation in our sample (which we note is partly duplicative with the individual polygenic score information). For example, in this secondary analysis Neolithic individuals were -3.48 cm shorter than expected on average relative to individuals from the Upper Paleolithic and Mesolithic (P=0.056). We also incorporated observations of paleopathological indicators of non-specific stress that can persist from childhood to adulthood in skeletal remains (linear enamel hypoplasia, cribra orbitalia, and porotic hyperostosis) into our model. Overall, our work highlights the potential of integrating disparate datasets to explore proxies of health in prehistory.

genomics↗