Observations of movement dynamics of flying insects using high resolution lidar

Insects are fundamental to ecosystem functioning and biodiversity, yet the study of insect movement, dispersal and activity patterns remains a challenge. Here we present results from a novel high resolution laser-radar (lidar) system for quantifying flying insect abundance recorded during one summer night in Sweden. We compare lidar recordings with data from a light trap deployed alongside the lidar. A total of 22808 insect were recorded, and the relative temporal quantities measured matched the quantities recorded with the light trap within a radius of 5 m. Lidar records showed that small insects (wing size 2.5 mm 2 in cross-section) were most abundant near the lidar beam before 22:00 and then moved towards the light trap between 22:00 and 23:30. We could distinguish three insect clusters based on morphology and found that two contained insects predominantly recorded above the field in the evening, whereas the third was formed by insects near the forest at around 21:30. Together our results demonstrate the capability of lidar for distinguishing different types of insect during flight and quantifying their movements

A roadmap for understanding the evolutionary significance of structural genomic variation

Author's accepted manuscriptStructural genomic variants (SVs) take diverse forms and are ubiquitous drivers of ecological and evolutionary processes. Most studies of SVs focus on the adaptive significance of gene duplications and large inversions. Future studies should catalog SVs of all types and sizes and systematically test their evolutionary implications. We propose a roadmap and definitions for the study of SVs in ecological and evolutionary genomics. Best practices for SV detection are needed to facilitate comparisons across studies. Integrating population genomic, theoretical, and experimental approaches to SVs will more comprehensively characterize genomic variation, uncover the adaptive and neutral processes shaping the evolutionary trajectory of SVs, and identify the mechanisms by which SVs impact adaptation and speciation.acceptedVersio

Rare Events in Remote Dark-Field Spectroscopy: An Ecological Case Study of Insects

In this paper, a novel detection scheme for the monitoring of insect ecosystems is presented. Our method is based on the remote acquisition of passive sunlight scattering by two insect species. Procedures to identify rare events in remote dark-field spectroscopy are explained. We further demonstrate how to reduce the spectral representation, and how to discriminate between sexes, using a hierarchical clustering analysis. One-day cycle showing the temporal activities of the two sexes as well as data on activity patterns in relation to temperature and wind is presented. We also give a few examples of the potential use of the technique for studying interactions between sexes on a time scale of milliseconds

Harnessing the Power of Genomics to Secure the Future of Seafood

Best use of scientific knowledge is required to maintain the fundamental role of seafood in human nutrition. While it is acknowledged that genomic-based methods allow the collection of powerful data, their value to inform fisheries management, aquaculture, and biosecurity applications remains underestimated. We review genomic applications of relevance to the sustainable management of seafood resources, illustrate the benefits of, and identify barriers to their integration. We conclude that the value of genomic information towards securing the future of seafood does not need to be further demonstrated. Instead, we need immediate efforts to remove structural roadblocks and focus on ways that support integration of genomic-informed methods into management and production practices. We propose solutions to pave the way forward.Peer reviewe

Environmental and Climatic Determinants of Molecular Diversity and Genetic Population Structure in a Coenagrionid Damselfly

Identifying environmental factors that structure intraspecific genetic diversity is of interest for both habitat preservation and biodiversity conservation. Recent advances in statistical and geographical genetics make it possible to investigate how environmental factors affect geographic organisation and population structure of molecular genetic diversity within species. Here we present a study on a common and wide ranging insect, the blue tailed damselfly Ischnuraelegans, which has been the target of many ecological and evolutionary studies. We addressed the following questions: (i) Is the population structure affected by longitudinal or latitudinal gradients?; (ii) Do geographic boundaries limit gene flow?; (iii) Does geographic distance affect connectivity and is there a signature of past bottlenecks?; (iv) Is there evidence of a recent range expansion and (vi) what is the effect of geography and climatic factors on population structure? We found low to moderate genetic sub-structuring between populations (mean FST = 0.06, Dest = 0.12), and an effect of longitude, but not latitude, on genetic diversity. No significant effects of geographic boundaries (e.g. water bodies) were found. FST-and Dest-values increased with geographic distance; however, there was no evidence for recent bottlenecks. Finally, we did not detect any molecular signatures of range expansions or an effect of geographic suitability, although local precipitation had a strong effect on genetic differentiation. The population structure of this small insect has probably been shaped by ecological factors that are correlated with longitudinal gradients, geographic distances, and local precipitation. The relatively weak global population structure and high degree of genetic variation within populations suggest that I. elegans has high dispersal ability, which is consistent with this species being an effective and early coloniser of new habitats

Introgression and rapid species turnover in sympatric damselflies

<p>Abstract</p> <p>Background</p> <p>Studying contemporary hybridization increases our understanding of introgression, adaptation and, ultimately, speciation. The sister species <it>Ischnura elegans </it>and <it>I. graellsii </it>(Odonata: Coenagrionidae) are ecologically, morphologically and genetically similar and hybridize. Recently, <it>I. elegans </it>has colonized northern Spain, creating a broad sympatric region with <it>I. graellsii</it>. Here, we review the distribution of both species in Iberia and evaluate the degree of introgression of <it>I. graellsii </it>into <it>I. elegans </it>using six microsatellite markers (442 individuals from 26 populations) and five mitochondrial genes in sympatric and allopatric localities. Furthermore, we quantify the effect of hybridization on the frequencies of the genetically controlled colour polymorphism in females of both species.</p> <p>Results</p> <p>In a principal component analysis of the microsatellite data, the first two principal components summarised almost half (41%) of the total genetic variation. The first axis revealed a clear separation of <it>I. graellsii </it>and <it>I</it>. <it>elegans </it>populations, while the second axis separated <it>I. elegans </it>populations. Admixture analyses showed extensive hybridization and introgression in <it>I. elegans </it>populations, consistent with <it>I. elegans </it>backcrosses and occasional F₁-hybrids, suggesting hybridization is on-going. More specifically, approximately 58% of the 166 Spanish <it>I. elegans </it>individuals were assigned to the <it>I. elegans </it>backcross category, whereas not a single of those individuals was assigned to the backcross with <it>I. graellsii</it>. The mitochondrial genes held little genetic variation, and the most common haplotype was shared by the two species.</p> <p>Conclusions</p> <p>The results suggest rapid species turnover in sympatric regions in favour of <it>I. elegans</it>, corroborating previous findings that <it>I. graellsii </it>suffers a mating disadvantage in sympatry with <it>I. elegans</it>. Examination of morph frequency dynamics indicates that hybridization is likely to have important implications for the maintenance of multiple female morphs, in particular during the initial period of hybridization.</p

Don't Fall Off the Adaptation Cliff: When Asymmetrical Fitness Selects for Suboptimal Traits

The cliff-edge hypothesis introduces the counterintuitive idea that the trait value associated with the maximum of an asymmetrical fitness function is not necessarily the value that is selected for if the trait shows variability in its phenotypic expression. We develop a model of population dynamics to show that, in such a system, the evolutionary stable strategy depends on both the shape of the fitness function around its maximum and the amount of phenotypic variance. The model provides quantitative predictions of the expected trait value distribution and provides an alternative quantity that should be maximized (“genotype fitness”) instead of the classical fitness function (“phenotype fitness”). We test the model's predictions on three examples: (1) litter size in guinea pigs, (2) sexual selection in damselflies, and (3) the geometry of the human lung. In all three cases, the model's predictions give a closer match to empirical data than traditional optimization theory models. Our model can be extended to most ecological situations, and the evolutionary conditions for its application are expected to be common in nature

Genomic structural variants involved in local adaptation of the European plaice

A recommendation – based on reviews by Three anonymous reviewers – of the article: Le Moan, A. Bekkevold, D. and Hemmer-Hansen J. (2020). Evolution at two time-frames: ancient and common origin of two structural variants involved in local adaptation of the European plaice (Pleuronectes platessa). bioRxiv, 662577, ver. 5 peer-reviewed and recommended by PCI Evol Biol. doi: 10.1101/662577. doi: 10.1101/66257

Women in evolution - highlighting the changing face of evolutionary biology

The face of science has changed. Women now feature alongside men at the forefront of many fields, and this is particularly true in evolutionary biology. This special issue celebrates the outstanding achievements and contributions of women in evolutionary biology, by highlighting a sample of their research and accomplishments. In addition to original research contributions, this collection of articles contains personal reflections to provide perspective and advice on succeeding as a woman in science. By showcasing the diversity and research excellence of women and drawing on their experiences, we wish to enhance the visibility of female scientists and provide inspiration as well as role models. These are exciting times for evolutionary biology, and the field is richer and stronger for the diversity of voices contributing to the field

Detecting Polygenic Evolution: Problems, Pitfalls, and Promises.

Unraveling the genetic basis of organismal form and function remains one of the major goals of evolutionary biology. Theory has long supported a model of polygenic evolution in which quantitative traits are underpinned by many genes of small effect, but empirical methods have lacked the power to detect causative loci when effect sizes are small or moderate. We (i) review traditional approaches used for identifying the molecular basis of phenotypic traits, to highlight the inherent problems and pitfalls that bias them towards the detection of large-effect loci. We then (ii) outline the promises of recent statistical frameworks to detect polygenic signatures of trait evolution, and discuss some of the first studies in evolutionary biology employing these approaches. Lastly, we (iii) outline future directions and point to areas that still need development