Sreetama Bhadra

Speciation shapes biodiversity, yet why some lineages diversify faster than others remains unclear. Theory predicts that traits promote ecological speciation through adaptation, but their evolvability (‘‘trait flexibility’’) may be impacted by allometric and genomic constraints. Here we test this by integrating phylogenetic, trait and genome size data for palms (Arecaceae) —a large pantropical family (>2,600 species) with 167-fold variation in certain traits (e.g., fruit size) and 60-fold genome size variation. Using structural equation modelling, we test three hypotheses: trait evolution promotes speciation (H1: trait flexibility hypothesis), and, speciation and trait evolution rates are constrained by allometry (H2: allometric constraint hypothesis) and genome size (H3: large genome constraint hypothesis). We detected seven major speciation rate shifts during approximately 110-million-years of palm evolution. Tip-derived speciation rates increased with faster evolution in leaf size and plant height, supporting H1, whereas correlated evolution between all traits indirectly influenced speciation, supporting H2. Large genomes decreased were associated with decreased plant height and stem diameter evolution rates supporting H3, but the genome size-speciation association was sensitive to phylogenetic autocorrelation. Our findings illustrate how the interplay between genome size, allometry and trait evolvability affect speciation, emphasizing the importance of holistic approaches for uncovering general mechanisms driving speciation throughout the Tree of Life.

Speciation shapes biodiversity, yet why some lineages diversify faster than others remains unclear. Theory predicts that traits promote ecological speciation through adaptation, but their evolvability (‘trait flexibility’) may be impacted by allometric and genomic constraints. Here we test this by integrating phylogenetic, trait and genome size data for palms (Arecaceae)—a large pantropical family (>2500 species) with 167-fold variation in certain traits (e.g. fruit size) and 60-fold genome size variation. Using structural equation modelling, we test three hypotheses: trait evolution promotes speciation (H1: trait flexibility hypothesis), and speciation and trait evolution rates are constrained by allometry (H2: allometric constraint hypothesis) and genome size (H3: large genome constraint hypothesis). We detected seven major speciation rate shifts during approximately 110-million-years of palm evolution. Tip-derived speciation rates increased with faster evolution in leaf size and plant height, supporting H1, whereas correlated evolution between all traits indirectly influenced speciation, supporting H2. Large genomes were associated with decreased plant height and stem diameter evolution rates supporting H3, but the genome size-speciation association was sensitive to phylogenetic autocorrelation. Our findings illustrate how the interplay between genome size, allometry and trait evolvability affect speciation, emphasizing the importance of holistic approaches for uncovering general mechanisms driving speciation throughout the Tree of Life.

Summary: The importance of functional trait evolution and genome size on plant speciation are well established, but their interactive effects remain untested in a single comparative macroevolutionary framework. We integrated phylogenetic, trait and genome size data for palms (Arecaceae) – a large pantropical family (>2600 species) with 167-fold variation in trait and 60-fold variation in genome size. We used structural equation modelling to test three key hypotheses: trait evolution promotes speciation (H1: trait flexibility hypothesis), and, speciation and trait evolution rates are constrained by allometry (H2: allometric constraint hypothesis) and genome size (H3: large genome constraint hypothesis). We detected seven major speciation rate shifts during the ca. 110-million-year history of palms. Tip-derived speciation rates increased with faster evolution in leaves and plant height, supporting H1, whereas correlated evolution between trait evolution rates indirectly influenced speciation, supporting H2. Large genomes decreased plant height and stem diameter evolutionary rates, but increased leaf size evolution and speciation rates, thus partly supporting H3. Our findings illustrate how the complex interplay between genome size, allometry and trait evolvability affect speciation, emphasizing the importance of holistic approaches in macroevolution. Furthermore, our results point to potential general mechanisms driving speciation rates throughout the plant Tree of Life.

The iDiv Female Scientists initiative at the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig in Germany was set up to connect women in science and to raise awareness of gender inequity. In this article we discuss the impact of the workplace environment on women in academia. Our experiences indicate that supportive workplace environments are more likely to discuss gender inequity, enabling “bottom-up” approaches where individual researchers can propose solutions to the problem. In contrast, unsupportive environments are less receptive to such discussions, so “top-down” approaches driven by legislation policies are required to improve the situation. We also make recommendations of actions that can be taken by individuals, institutions and policymakers to promote gender equity.

Introduction: Most global biodiversity is in developing economies. Decades of capacity building should have built sufficient in-country capacity to develop biodiversity baselines; yet has effort provided the expertise to build these baselines?Methods: Grants and access to research opportunities are often linked to success in publishing, with the H-index providing the main metric of academic success. Recent compilations of “Top Researchers in Ecology and Evolution” included 5,419 researchers, but where these researchers are and how representative they are has not been well studied. We explored the global distribution of “Top Researchers in Ecology and Evolution” and explored the representation of Women, non-Caucasians, and non-Caucasian women, as well as the representation of “local” top researchers in different regions.Results: Over half Top Researchers in Ecology and Evolution are from just three countries (United States, United Kingdom, and Australia), and 83% come from 12 higher-income countries. Even in lower-income economies the majority of the few “high impact” researchers are originally from higher-income economies. Only China had a high proportion of their high-impact non-Caucasian researchers, with the majority of researchers coming from that region. Women were also underrepresented across the globe, only three countries had more than 20% of top-performing ecologists being female.Discussion: Ultimately, despite decades of capacity building, we are still failing to build in-country capacity for research or to provide sufficient support for female ecologists to publish and lead the field. Here we discuss why these issues persist, and how we might improve representation and access to opportunity and support for all groups, and provide the analysis needed to provide solutions to global challenges in biodiversity conservation, which require diverse representation to develop effective, and nuanced solutions.

Sentinel plasticine prey has been increasingly used to estimate predation pressure. The use of plasticine prey may, however, bias the results, as this method was originally designed to account for predation by organisms that can visually recognize the shapes and colors of their prey. To evaluate the limitations of using sentinel plasticine prey, we compared predator attack rates between real prey – dead and live mealworms, Tenebrio molitor L. (Coleoptera: Tenebrionidae) – and plasticine models in a monsoonal tropical rainforest of southeastern China. The attack rates by invertebrates were highest on dead prey followed by live prey and plasticine models, whereas the attack rates by vertebrates were lowest on dead prey, and did not differ between live prey and plasticine models. These results confirm that bias imposed by using the plasticine models is affected by the type of predators. In addition, we tested the validity and generality of the premise that predators can distinguish the shapes of plasticine model prey and preferentially attack a caterpillar‐like shape over other shapes. To test this hypothesis, we conducted three independent experiments in China, Papua New Guinea, and Finland. In the two latter localities, predation rates on plasticine caterpillars were higher than on models of other shapes, whereas in China, these differences were not significant. Taken together, our study suggests that plasticine models may underestimate the predation by invertebrates to a greater extent than predation by vertebrates, and the preference of model shape by predators may be locality‐specific, presumably due to differences in the composition of the predator community. We propose that predation be estimated on both live and plasticine prey in future studies to measure the potential bias imposed by using plasticine models and its variation among various habitats and predator groups.

Chenopodium quinoa Willd. is rapidly gaining importance worldwide as a superfood. However, structural diversity and asymmetry analyses of chromosomes of different cultivars of the species are largely understudied primarily owing to their small chromosomes. In this paper, karyomorphological investigations were performed on 21 cultivars of C. quinoa with varying seed morphology cultivated widely in the highland regions of the Andes, which is the center of domestication of this species. Somatic chromosome number was found to be 2n= 36 in all cultivars with no occurrence of mixoploidy. Lengths of individual chromosomes varied between 0.63–6.53 ?m, with their short arms ranging from 0.25–2.95 ?m and long arms between 0.38–3.58 ?m. Types of primary constriction ranged from median to sub–terminal. One pair of chromosome in each complement possessed a secondary constriction. Chromosome complements of all cultivars belonged to the asymmetry class 2B with an average asymmetry index value of 3.21±0.61. Values of intra- and inter-chromosomal asymmetry indices were 0.30±0.02 and 0.20±0.02 respectively across all cultivars. The average coefficients of variation of chromosome lengths was 19.77±2.11 and average centromeric index was 16.28±2.12. Arm ratio of the chromosomes varied from 0.34 to 5.76. The mean values of karyotypic asymmetry, symmetry index and karyotype asymmetry index percentage were 17.69±1.53, 147.69±5.54 and 58.71±0.86 respectively. Pearson correlation revealed strong correlation within inter– and intra–chromosomal asymmetry indices. Our analyses uncovered higher chromosomal variation in quinoa than previously found with high inter–varietal similarities among the studied cultivars, revealed from scattered diagrams between asymmetry indices.