Crossbreeding reveals the scale and genetic architecture of local adaptation in a predominantly selfing Hordeum spontaneum

Environmental variation can be large across a wide range of spatial scales resulting in complex patterns of local adaptation across species ranges. We analyzed the scale, genetic mechanism and direct climatic causes of local adaptation in a widely distributed grass Hordeum spontaneum. We performed artificial crosses of maternal plants representing the same Negev desert population with plants originating elsewhere. Pollen donors were plants from other Negev desert populations, non-desert Israeli populations sampled along an aridity gradient, and accessions covering the entire species range. Our study included planting of inter-population hybrids under favorable and simulated desert experimental conditions, followed by analysis of their performance, variation in adaptive traits and relationship with climatic parameters at sampling locations. The combined results of parental phenotypic variation and performance of hybrids were consistent with local selection, reflecting the importance of both regional and local climates. The adaptive genetic differentiation of barley desert populations had a complex architecture. None of the three effects (additive, dominance and epistasis) were fully responsible for this differentiation. Although genetic effects not related to extrinsic selection appear to contribute to genetic differentiation in barley, epistatic effects arising from local selection clearly predominated. The short-term effect of gene flow by pollen was generally negative, indicating that a majority of the new allele combinations created by recombination were maladaptive. However, the long-term effect of occasional pollen flow from other desert populations appears to be positive, as some new recombined genotypes were superior in fitness to the maternal plants even in the F2 generation.

Tasking Students With Empathy: Field Observations, COVID-19, and Assessing an Anthropological Sensibility

In 2019 and 2020 students in an Australian university conducted a short ethnographic exercise, a ‘journal’, with an attunement to the multiplicity of meanings evident in a single space by a range of interlocutors. We emphasised and assessed ‘empathy’ as a short-hand for the kind of anthropological sensibility we hoped to encourage. By requesting an account that represented an awareness of how ‘others’ encounter and come to ‘know’ the world we promoted their adoption of a modality which is central to the discipline. We wanted them to describe the world—the terrain, the stuff of their surroundings—based on their observations of how these others behaved. To couch it in anthropological terms, we wanted them to be attuned to a multiplicity of ‘taskscapes’, Ingold’s term for the mutual constitution of people and places through culturally politically, economically, and spiritually informed actions (‘tasks’) (Ingold, 1993). These ‘taskscapes’ were illustrated through the work of McKee (2016), whose account of multiple simultaneous experiences in the Negev desert by those living in (variously labelled) Israel/Palestine, represented an unexperienced domain for most of the Australian students. Rather than reinforcing the dated notion that anthropology is something that is done ‘elsewhere’, by asking students to focus on anthropology ‘at home’ they embodied their understanding of a transferable concept—introduced via an ‘exotic’ example—through a locally embedded experience. This paper describes the delivery of this assignment in 2019 and 2020 and explores in detail the content of five student journals and their evidence of the targeted learning.

FTIR BONE CHARACTERIZATION AND RADIOCARBON DATING: TIMING THE ABANDONMENT OF BYZANTINE PIGEON TOWERS IN THE NEGEV DESERT, ISRAEL

ABSTRACT Various archaeological and historical evidence shows that the marginal area of the Negev desert of southern Israel enjoyed great agricultural prosperity in the Byzantine period (4th–7th centuries CE). Among the different types of agricultural installations are pigeon towers, which were built near the fields to produce fertilizer to enrich the nutrient-poor desert soils. Such extensive specialized agriculture practice was much less applied in the Negev in the successive Early Islamic period in the mid-7th century. Here we recovered in situ pigeon bones from five pigeon towers in the Negev, applied multiple characterization methods (FTIR, grinding curve, and C/N ratio) to estimate the preservation of bones, and achieved absolute dating for the abandonment of the towers. The obtained dates indicate rapid decline of agricultural activities in the second half of the 6th century CE and beginning of the 7th century. These findings, together with other evidence for Byzantine decline of agricultural hinterland and urban dysfunction of the settlements, suggest that the farming activities in the Negev declined in the Late Byzantine period (550–640 CE) and support the hypothesis that climatic-driven causes were the main trigger for the eventual cultural-societal decline of the Negev region.

Red/far-red light signals regulate the activity of the carbon-concentrating mechanism in cyanobacteria

Desiccation-tolerant cyanobacteria can survive frequent hydration/dehydration cycles likely affecting inorganic carbon (Ci) levels. It was recently shown that red/far-red light serves as signal-preparing cells toward dehydration. Here, the effects of desiccation on Ci assimilation by Leptolyngbya ohadii isolated from Israel’s Negev desert were investigated. Metabolomic investigations indicated a decline in ribulose-1,5-bisphosphate carboxylase/oxygenase carboxylation activity, and this was accelerated by far-red light. Far-red light negatively affected the Ci affinity of L. ohadii during desiccation and in liquid cultures. Similar effects were evident in the non–desiccation-tolerant cyanobacterium Synechocystis. The Synechocystis Δcph1 mutant lacking the major phytochrome exhibited reduced photosynthetic Ci affinity when exposed to far-red light, whereas the mutant ΔsbtB lacking a Ci uptake inhibitory protein lost the far-red light inhibition. Collectively, these results suggest that red/far-red light perception likely via phytochromes regulates Ci uptake by cyanobacteria and that this mechanism contributes to desiccation tolerance in strains such as L. ohadii.