Modeling Sexual Differences of Body Size Variation in Ground Beetles in Geographical Gradients: A Case Study of Pterostichus melanarius (Illiger, 1798) (Coleoptera, Carabidae)

The aim of this study was to test the steepness of body size variation in males and females in the widespread ground beetle Pterostichus melanarius in geographical gradients. Beetles were sampled in 15 regions of Europe and Asia, and sampling territories differed 17° in latitude and 121° in longitude. We measured six linear traits in every captured beetle and formed a data set that included 2154 individuals. Body size variation in all traits in general was sawtooth, both in latitude and in longitude gradients. Regression analysis showed slight trends: in the latitude gradient, elytra parameters increased, pronotum length did not change but the width increased, and head parameters decreased. In the longitude gradient, the changes were as follows: elytra length increased, but its width did not change; pronotum length did not change, but its width increased; the head parameters decreased. Thus, we observed the elytra length increase and the head parameters decrease northwards and eastwards. We compared female and male regression curves (trait size on latitude/longitude): p-levels were significant only in four cases out of 12. Thus, we conclude that, in general, there is no evidence for the steepness in trait variation in males compared with females.

Relations in the Size Variation of Plant Organs: a Case Study of Staghorn Sumac Leaves and Longleaf Pine Cone Scales

Plants automatically control the size variations in organs to achieve efficient exploitation of resources. However, it is unclear whether the scaling relationships of plant organs share a similar character for different individuals under varied micro-conditions (e.g., light and soil water). We conducted a case study of the lengths of staghorn sumac leaves and longleaf pine cone scales to test the relationships. Our results indicated that although there were size variations, there existed power laws of frequency in the lengths of staghorn sumac leaves and longleaf pine cone scales. The exponents differed but were positively correlated with the minimum length of leaves or cone scales. Taylor’s Law existed in the lengths of cone scales and some tree leaves, and scale break was observed. This study provides new information on scaling relationships and self-organization in the patterns of tree parts arrangement. Taylor’s Law may be used to detect minor changes in the growth regime.

Genome size variation in Deschampsia cespitosa sensu lato (Poaceae) in Eurasia

The grass Deschampsia cespitosa is a variable taxon out of which many varieties, subspecies and endemic species have been separated. In this paper, the variation in genome size (GS) and ploidy of this grass including several of its subspecies and two related species in Eurasia was investigated by flow cytometric (FCM) measurements. GS and ploidy data were also related to specific environments and reproduction mode. Ploidy levels found by FCM were confirmed by chromosome counts of diploid (2n = 28) and tetraploid (2n = 52) samples. Seminiferous (seed bearing) D. cespitosa was mainly diploid (GS between 3.754 and 5.438 pg/1C). GS variation in diploids showed a geographic pattern with a significant difference (H = 41,441, P < 0.001) between European (median = 4.377 pg) and Asian (median = 4.881 pg) accessions. Genome size (1C) in tetraploids ranged from 7.9426 to 9.0399 pg. Tetraploid seminiferous D. cespitosa was found mostly in disturbed habitats in western and southern Europe, while tetraploids in Asia were registered in wet Arctic habitats. Genome size (1C between 8.3278 and 8.8603 pg) of the pseudoviviparous plants (spikelets produce plantlets asexually) of wet habitats in central and northern Europe indicated tetraploidy. A putative triploid (GS 6.6817 pg) was detected in Iceland. Summing up, we found a high variation in GS on the geographic scale with significant regional differences in diploid D. cespitosa. Among the tetraploids, the asexually reproducing plants were bound to specific habitats, while the seminiferous plants showed a habitat preference similar to the diploids.

A simple island biodiversity model is robust to trait dependence in diversification and colonization rates

The application of state-dependent speciation and extinction (SSE) models to phylogenetic trees has revealed an important role for traits in diversification. However, this role remains comparatively unexplored on islands, which can include multiple independent clades resulting from different colonization events. Here, we perform a robustness study to identify how trait-dependence in rates of island colonization, extinction and speciation (CES rates) affects the estimation accuracy of a phylogenetic model that assumes no rate variation between trait states. We extend the DAISIE (Dynamic Assembly of Islands through Speciation, Immigration and Extinction) simulation model to include state-dependent rates, and evaluate the robustness of the DAISIE inference model using simulated data. Our results show that when the CES rate differences between trait states are moderate, DAISIE shows negligible error for a variety of island diversity metrics. However, for large differences in speciation rates, we find large errors when reconstructing clade size variation and non-endemic species diversity through time. We conclude that for many biologically realistic scenarios with trait-dependent speciation and colonization, island diversity dynamics can be accurately estimated without the need to explicitly model trait dynamics. Nonetheless, our new simulation model may provide a useful tool for studying patterns of trait variation.

Note on Historical Records, Geographical Distribution, and Ecological Characteristics of a Mud Lobster, Thalassina anomala (Herbst, 1804) (Decapoda, Gebiidea, Thalassinidae) in Sarawak, Borneo

The presence of mud lobster mounds is a common natural feature along coastal areas and tidal influence habitats in Sarawak. However, the number of species of mud lobsters that constructed the mounds is yet to be ascertained. This paper reviews historical records and geographical distribution of mud lobster in Sarawak from various forms of literature. The early records of mud lobster were from Buntal in Kuching, and Lingga in Sri Aman back more than 130 years ago. A few other records were reported from the central and northern regions of Sarawak between 1928 and 2019. All these records have identified mud lobster of Sarawak as Thalassina anomala (Herbst, 1804). Our present study at two sites in Buntal area with a careful examination of morphological characters of fresh specimens has confirmed the taxonomy of the species and its existence in the area. Some ecological characteristics of the mud lobster, such as size variation, population density, and mound characteristics, are also discussed. The present study also found that construction of massive mounds by mud lobster has posed a conflict to farmers and coastal communities at Buntal area, who regarded the animal as a pest. On the other hand, research on the potential medicinal value of mud lobster in Sarawak is growing. This implies that accurate taxonomy and comprehensive ecological data of T. anomala are necessary to support best practices of mud lobster pest management and sustainable harvesting of the animal for medicinal purposes, which eventually lead to conserving the animal.

Karyotype and genome size variation in white-flowered Eranthis sect. Shibateranthis (Ranunculaceae)

Comparative karyomorphological analyses of six out of the eight white-flowered species of Eranthis sect. Shibateranthis have been carried out. All studied specimens of E. byunsanensis, E. lobulata, E. pinnatifida, and E. stellata had a somatic chromosome number 2n = 16 with basic chromosome number x = 8. On the contrary, E. tanhoensis and E. sibirica had a basic chromosome number x = 7. The specimens of E. tanhoensis were diploid with 2n = 14, while the specimens of E. sibirica were polyploid with 2n = 42. Monoploid chromosome sets of the investigated diploid species had 4–5 metacentric chromosomes and 2–4 submetacentric/subtelocentric/acrocentric chromosomes. The highest level of interchromosomal asymmetry, estimated via CVCL, was found in E. byunsanensis and E. pinnatifida. The highest levels of intrachromosomal asymmetry (MCA) and heterogeneity in centromere position (CVCI) were found in E. lobulata and E. byunsanensis, while E. sibirica had the most symmetric karyotype. A multivariate PCoA analysis of basic karyotype parameters (2n, x, THL, CVCL, MCA, and CVCI) highlighted no overlap among species accessions, which was also confirmed by LDA. The average absolute monoploid DNA content (1Cx) of the 23 investigated samples of six Eranthis species varied from 9.26 ± 0.25 pg in E. sibirica to 15.93 ± 0.32 pg in E. stellata. Overall karyological affinity was highlighted between E. lobulata and E. stellata, on one side, and between E. byunsanensis and E. pinnatifida, on the other side. Interestingly, there was no significant correlation between total haploid (monoploid) chromosome length (THL) and 1Cx values in these species.

Automated SEM Image Analysis of the Sphere Diameter, Sphere-Sphere Separation, and Opening Size Distributions of Nanosphere Lithography Masks

Colloidal nanosphere monolayers—used as a lithography mask for site-controlled material deposition or removal—offer the possibility of cost-effective patterning of large surface areas. In the present study, an automated analysis of scanning electron microscopy (SEM) images is described, which enables the recognition of the individual nanospheres in densely packed monolayers in order to perform a statistical quantification of the sphere size, mask opening size, and sphere-sphere separation distributions. Search algorithms based on Fourier transformation, cross-correlation, multiple-angle intensity profiling, and sphere edge point detection techniques allow for a sphere detection efficiency of at least 99.8%, even in the case of considerable sphere size variations. While the sphere positions and diameters are determined by fitting circles to the spheres edge points, the openings between sphere triples are detected by intensity thresholding. For the analyzed polystyrene sphere monolayers with sphere sizes between 220 and 600 nm and a diameter spread of around 3% coefficients of variation of 6.8–8.1% for the opening size are found. By correlating the mentioned size distributions, it is shown that, in this case, the dominant contribution to the opening size variation stems from nanometer-scale positional variations of the spheres.

Comparative genomics and evolution of avian specialized traits

Genomic data are important for understanding the origin and evolution of traits. Under the context of rapidly developing sequencing technologies and more widely available genome sequences, researchers are able to study evolutionary mechanisms of traits via comparative genomic methods. Compared with other vertebrates, bird genomes are relatively small and exhibit conserved synteny with few repetitive elements, which makes them suitable for evolutionary studies. Increasing genomic progress has been reported on the evolution of powered flight, body size variation, beak morphology, plumage coloration, high-elevation colonization, migration, and vocalization. By summarizing previous studies, we demonstrate the genetic bases of trait evolution, highlighting the roles of small-scale sequence variation, genomic structural variation, and changes in gene interaction networks. We suggest that future studies should focus on improving the quality of reference genomes, exploring the evolution of regulatory elements and networks, and combining genomic data with morphological, ecological, behavioral, and developmental biology data.