Shani Inbar

Urbanisation is a pervasive global phenomenon that exerts strong influence on biodiversity and ecosystems. Many species can thrive in urban landscapes by capitalising on generalist traits and environmental resilience; however, this does not safeguard against potential biases exerted by urban environments on population processes. The Egyptian fruit bat ( Rousettus aegyptiacus ) is a species with both urban and rural distribution across its range, and some populations show behavioural and physiological differences. Using reduced representation genome sequencing (ddRAD‐seq), we tested for genetic underpinnings of these differences between urban and rural bat populations sampled across Israel. Despite a genetically homogenous landscape presenting no population structure, we show clear isolation by distance and landscape effects on genetic connectivity, where open areas, but not urbanisation, constitute a barrier to movement. Using genotype‐environment association analysis, we identify 59 candidate SNPs spanning 56 genes potentially associated with urbanisation. This suite of genes entails wide‐ranging functions including neurotransmission, metabolism, gene expression regulation, reproductive biology, and retinoic acid and sensory function. Gene Ontology enrichment analysis revealed non‐random functional clustering with exceptional enrichment in GABAergic synapse components (98.6‐fold), monoatomic ion transport (122.2‐fold), and ATP‐dependent chromatin remodelling (68.6‐fold), evidencing coordinated selection across interconnected neural, metabolic, and regulatory systems. A predominance of intronic variants within this candidate SNP suite (51/59) is suggestive that adaptation in response to urbanisation proceeds primarily through changes in gene regulation, rather than protein‐coding modifications. This study shows how a highly mobile species may undergo microevolutionary shifts in response to urban pressures despite ongoing gene flow, elucidating the complex interplay between genetics and the urban environment in a non‐model organism.

In modern English, common sense refers to an intuitive capacity to grasp self-evident truths and make judgments that require no special training or expertise. Although often treated as universal and ahistorical, its standing as an epistemic authority, especially within the sciences, has been contested, revised, and reconfigured over the past two centuries. Yet scientists’ assumptions about the reliability of common sense typically remain implicit, embedded in a normative background that is rarely examined but quietly guides scientific thought. This paper examines how different attitudes toward common sense are reflected in the aesthetic choices and visual references scientists use. Through three case studies—Ernst Haeckel, Conrad Waddington, and Ginsburg & Jablonka—we demonstrate how their respective views, firmly rooted in their historical context, are made accessible through their aesthetic choices. Examining these choices reveals that scientific images, particularly those with artistic qualities, do more than depict scientific knowledge; they reflect underlying normative commitments, shaping what is seen as intelligible and scientifically meaningful. They are sites where scientific sensibilities and epistemic commitments become visible and available for critique. Drawing on Kant’s notion of sensus communis, we suggest that aesthetic judgments, particularly of scientific representations, provide a reflective standpoint from which such implicit commitments can be evaluated.

Nestmate recognition is the basis for cooperation within social insect colonies. Quantitative variation in cuticle hydrocarbons (CHCs) is used for nestmate recognition in ants and other social insects. We carried out a Genome Wide Association Study (GWAS) of CHCs in the desert ant Cataglyphis niger by sampling 47 colonies, fully sequencing six workers from each colony, and measuring the relative amounts of their CHCs. Under the Gestalt colony odour model, social interactions between nestmates, in which CHCs are being transferred and mixed, are essential in creating a uniform colony CHC profile. Therefore, we carried out a second GWAS between the colonies and their uniform Gestalt odour by averaging nestmate genotypes and comparing them to their averaged CHC amounts. Our results are in line with the Gestalt model. Together, the two analyses identified 99 candidate QTLs associated with 18 of the CHCs. Thirteen clusters of two to four QTLs located within 10cM from each other were identified, seven of which contained QTLs from both analyses. We conclude that nestmate recognition cues are a complex quantitative colony-level trait with a significant genetic component to their phenotypic variation and a highly polygenic architecture.

Social insect colonies exhibit colony-level phenotypes such as social immunity and task coordination, which are produced by the individual phenotypes. Mapping the genetic basis of such phenotypes requires associating the colony-level phenotype with the genotypes in the colony. In this paper, we examine alternative approaches to DNA extraction, library construction, and sequencing for genome wide association studies (GWAS) of colony-level traits using a population sample of Cataglyphis niger ants. We evaluate the accuracy of allele frequency estimation from sequencing a pool of individuals (pool-seq) from each colony using either whole-genome sequencing or reduced representation genomic sequencing. Based on empirical measurement of the experimental noise in sequenced DNA pools, we show that reduced representation pool-seq is drastically less accurate than whole-genome pool-seq. Surprisingly, normalized pooling of samples did not result in greater accuracy than un-normalized pooling. Subsequently, we evaluate the power of the alternative approaches for detecting quantitative trait loci (QTL) of colony-level traits by using simulations that account for an environmental effect on the phenotype. Our results can inform experimental designs and enable optimizing the power of GWAS depending on budget, availability of samples and research goals. We conclude that for a given budget, sequencing un-normalized pools of individuals from each colony provides optimal QTL detection power. Genomic mapping techniques are used to map phenotypes to genotypes. Mapping is of general interest in any biological system, including fundamental studies of biological traits, clinical studies of genetic predisposition to disease, and agro- and bio-technological studies of domesticated plants and animals. Typically, such studies associate phenotypic measurements of individuals with their genotypes. Here we evaluate methodological approaches for genomic mapping of phenotypes that are expressed at the level of a group rather than that of individuals. We demonstrate that genomic sequencing of a DNA pool from multiple samples provides increased statistical power within a limited budget. Our results facilitate more efficient use of resources in genomic mapping studies that investigate group-level phenotypes.

Cuticualar hydrocarbons play an important role in chemical communication in social insects, serving, among other things, as nestmate, gender, dominance and fertility recognition cues. In ants, however, very little is known about the precopulatory signals cuticular hydrocarbons carry. These signals may serve as affecting sex pheromones and aphrodisiacs or as reliable signals for idiosyncratic traits, which indirectly affect sexual selection. In this study, we examined, for the first time, in the Cataglyphis genus, sex-specific variability in cuticular hydrocarbons. We focused on a species that exhibits split sex-ratio and found significant quantitative differences between virgin queens and their potential mates. In an analyses of both absolute amounts and relative amounts, we found different compounds to be significantly displayed on gynes and drones, suggesting absolute and relative amounts may carry different signals influencing mating behavior and mate choice. We discuss the possible signals advertised by the non-polar fraction of these hydrocarbon profiles.

Species are the fundamental units upon which evolutionary research is based. In insects, due to the high level of hybridization, the delimitation of such species can be challenging. The genus Cataglyphis presents a high level of diversification, making it an excellent model with which to study evolutionary paths. Israel appears to be a 'hot spot' for recent speciation in this genus. Although previous studies have described multiple species of Cataglyphis in Israel, a recent genetic study has questioned the existence of some of these historically described species. The present study focuses on an apparent species complex that is distinguishable by its mitochondrial DNA (and therefore named mitotypes) but not by its nuclear DNA. Using a multi-method approach (genetics, chemistry and behavior), we show that these mitotypes also differ in their social structures and are readily distinguishable by their cuticular hydrocarbons profiles. While the different mitotypes are in general allopatric, at our study site they all coexist but nonetheless maintain the observed differences between them. This raises many evolutionary questions: Are these incipient species that have diverged with gene flow, or is this a case of social and chemical polymorphism that is maintained within a single species.

Social insect colonies exhibit colony-level phenotypes such as social immunity and task coordination, which are the sum of individual phenotypes. Mapping the genetic basis of such phenotypes requires associating the colony-level phenotype with the genotypes in the colony. In this paper, we examine alternative approaches to DNA extraction, library construction and sequencing for genome wide association (GWAS) studies of colony-level traits. We evaluate the accuracy of allele frequency estimation in sequencing a pool of individuals (pool-seq) from each colony in either whole-genome sequencing or reduced representation genomic sequencing. Based on empirical measurement of the experimental noise in sequencing DNA pools, we show that whole-genome pool-seq is more accurate than reduced representation pool-seq. We evaluate the power of the alternative approaches for detecting quantitative trait loci (QTL) of colony-level traits by using simulations that account for an environmental effect on the phenotype. Our results can inform experimental designs and enable optimizing the power of GWAS depending on budget, availability of samples and research goals. We conclude that for a given budget, sequencing un-normalized pools of individuals from each colony achieves greater QTL detection power.

In social insects, non-nestmates interactions are typically agonistic and many factors may influence the degree of exhibited aggression. Two of these factors are the physical proximity between nests and the chemical dissimilarity between colonies’ chemical signatures. We studied a population sample of 43 colonies of Cataglyphis niger ants distributed along a transect of ∼4KM. This geographic distribution allowed us to examine correlations of aggression levels with physical and chemical distances. Ants were collected before mating season, when sexuals (unmated gynes and drones) could be found in nests. In our sample, colonies had either gynes or drones but never both. The presence of sexuals, therefore, was another factor we took into account in our behavioral analyses. Workers from nests with sexuals were more aggressive towards conspecifics than workers from nests where sexuals were absent. We also found those workers to be more vigorously active towards colonies with greater chemical distances, while workers from nests without sexuals were indifferent to chemical distances. We therefore concluded that ants are able to detect differences in chemical dissimilarity, but their aggression levels are mainly determined by other mechanisms. A possible additional mechanism is associative learning and long term memory of the chemical signatures of neighboring colonies. Such learning is supported by our finding that aggression is higher towards neighboring nests, which is in line with the previously reported ‘nasty neighbour’ effect in Cataglyphis ants. These results suggest that previous experience and learning of neural templates representing neighbors’ chemical cues is a stronger component than chemical dissimilarity in the mechanisms which determine aggression towards conspecifics in this species. We discuss possible explanations for the observed effect of the presence of sexuals on agonistic behavior and responsiveness to chemical distances.