Is 2020 the year when primatologists should cancel fieldwork?

Year 2020 has brought the greatest global pandemic to hit the world since the end of the First World War. The severe acute respiratory syndrome coronavirus 2 and the resulting disease named coronavirus disease 2019 has brought the world to its knees both financially and medically. The American Society of Primatologists has postponed their annual meetings from the end of May 2020 until the end of September 2020, while the International Primatological Society have postponed their biennial congress from August 2020 to August 2021, which has also resulted in their 2022 meetings in Malaysia being pushed back until 2023. Here, I explore the potential dangers of pursuing any primate fieldwork during this pandemic on our study species, their ecosystems, and local peoples. I believe that the risk of bringing this virus into our study ecosystems is too great and that primatologists should cancel all field research until the pandemic ends or a vaccine/reliable treatment is widely available. This is the year we all must become One Health practitioners!     

Community assembly: when should history matter?

Community assembly provides a conceptual foundation for understanding the processes that determine which and how many species live in a particular locality. Evidence suggests that community assembly often leads to a single stable equilibrium, such that the conditions of the environment and interspecific interactions determine which species will exist there. In such cases, regions of local communities with similar environmental conditions should have similar community composition. Other evidence suggests that community assembly can lead to multiple stable equilibria. Thus, the resulting community depends on the assembly history, even when all species have access to the community. In these cases, a region of local communities with similar environmental conditions can be very dissimilar in their community composition. Both regional and local factors should determine the patterns by which communities assemble, and the resultant degree of similarity or dissimilarity among localities with similar environments. A single equilibrium in more likely to be realized in systems with small regional species pools, high rates of connectance, low productivity and high disturbance. Multiple stable equilibria are more likely in systems with large regional species pools, low rates of connectance, high productivity and low disturbance. I illustrate preliminary evidence for these predictions from an observational study of small pond communities, and show important effects on community similarity, as well as on local and regional species richness.     

Are the new Ediacaran Doushantuo embryo-like fossils early metazoans? A reply

Chen et al. (2014) described a suite of one-celled, Parapandorina-stage, Megaclonophycus-stage (some with dyads and tetrads), and matryoshka-stage fossils from the Doushantuo Formation, and interpreted them as representing a sequence of ontogenetic stages of the animal embryo-like fossil Megasphaera. Tang (2015) argues that the matryoshkas might have been parasites or symbionts, rather than developmental products of dyads and tetrads in Megaclonophycus-stage fossils. Assessing Tang's (2015) arguments against available evidence, we conclude that the matryoshkas likely represent an ontogenetic stage of Megasphaera. As such, they have the potential to illuminate the developmental biology, life cycle, and phylogenetic affinity of the enigmatic fossil Megasphaera.     

Ecology in the university first year?

The inclusion of ecology in first-year university biology courses presents considerable difficulties. The new course being evolved at Bath centres round three main themes—spatial distribution, the flow of energy, and the gene as an element of continuity. Practical work presents particular problems on account of the large number of students and a lack of time. The difficulty can be overcome to some extent by the use of simulation experiments which aim to reproduce in miniature within the laboratory certain restricted aspects of the real environment. Bearing in mind that, at most, only one visit to a natural habitat will be possible, it is important that full use should be made of good visual aids such as films and slides. Facilities must also be provided for students to check their own progress through problems derived from second-hand sources such as research papers.     

Divide and conquer: when and how should competitors share?

When two individuals are unwilling to fight over a valuable resource, then they may obtain it with equal probability, or they may choose to divide the resource in some way. Although both strategies have been observed in nature, modelers have so far implicitly assumed that their long-term payoffs are the same. First we show that increasing returns to size in the value of a resource favor random allocation over sharing, whereas diminishing returns favor the reverse. Next we extend our approach to understand the conditions under which sharing will evolve when contestants vary in their resource-holding potential. We show that although closely matched individuals are more likely to share, it is by no means a prerequisite when contestants have limited information about one another’s abilities. Collectively, our models support recent observations of physical sharing as a solution to conflict resolution, and elucidate the conditions under which sharing will arise.     

Can three incongruence tests predict when data should be combined?

Advocates of conditional combination have argued that testing for incongruence between data partitions is an important step in data exploration. Unless the partitions have had distinct histories, as in horizontal gene transfer, incongruence means that one or more data support the wrong phylogeny. This study examines the relationship between incongruence and phylogenetic accuracy using three tests of incongruence. These tests were applied to pairs of mitochondrial DNA data partitions from two well-corroborated vertebrate phylogenies. Of the three tests, the most useful was the incongruence length difference test (ILD, also called the partition homogeneity test). This test distinguished between cases in which combining the data generally improved phylogenetic accuracy (P > 0.01) and cases in which accuracy of the combined data suffered relative to the individual partitions (P < 0.001). In contrast, in several cases, the Templeton and Rodrigo tests detected highly significant incongruence (P < 0.001) even though combining the incongruent partitions actually increased phylogenetic accuracy. All three tests identified cases in which improving the reconstruction model would improve the phylogenetic accuracy of the individual partitions.      

How should we assess risk behaviour when determining donor deferral? Reflections on the MSM deferral

Concerns are increasingly being raised in a number of countries in relation to the behavioural donor criteria and in particular the on-going permanent exclusion of men who have had sex with other men (MSM). The justification for this is broadly linked to the use of risk models. Generally current exclusion criteria are broadly defined and indirectly it might be argued that this leads to exclusion based on sexual orientation. Available data indicates compliance issues with the exclusion and recent reviews in Europe have recommended that further research in this area is needed before any change in the current permanent exclusion should be made. Lobby groups however promote a more targetted approach to behavioural criteria. Firm data to support this is however currently lacking. There are a number of possible approaches to assessing risk including the period since the activity took place, the number of partners in a given period, the type of sex act or a combination of these factors. Definition of an optimal approach will need to consider both the sensitivity and specificity of the intervention along with an assessment of ease and consistency of application.     

Which functional groups of the molybdopterin ligand should be considered when modeling the active sites of the molybdenum and tungsten cofactors? A density functional theory study

A density functional theory study of the influence of the various functional groups of the molybdopterin ligand on electronic and geometric properties of active-site models for the molybdenum and tungsten cofactors has been undertaken. We used analogous molybdenum and tungsten complexes with increasingly accurate representation of the molybdopterin ligands and compared bond lengths, angles, charge distribution, composition of the binding orbitals, as well as the redox potentials in relation to each other. On the basis of our findings, we suggest using ligand systems including the pyrane and the pyrazine rings, besides the dithiolene function, to obtain sufficiently reliable computational, but also synthetic, models for the molybdenum and tungsten cofactors, whereas the second ring of the pterin might be neglected for efficiency reasons.     

Where and when the earliest coccolithophores?

Gardin, S., Krystyn, L., Richoz, S., Bartolini, A. & Galbrun, B. 2012: Where and when the earliest coccolithophores? Lethaia, Vol. 45, pp. 507–523. New calcareous nannofossil analyses from the Northern Calcareous Alps of Austria are herein used to update and improve the state of knowledge about the oldest occurrence of coccolithophores reported in the literature. Previously reported Norian occurrences of coccoliths were based on an obsolete Triassic chronostratigraphy, in which the Rhaetian stage was subsumed into the Norian (‘Sevatian 2’). The oldest stratigraphical record of coccoliths spp. lies just below the Norian‐Rhaetian boundary and the first coccolith species, Crucirhabdus minutus, is recorded from the base of Rhaetian stage. The latter bio‐event is located just above the First Occurrence of the conodont Misikella posthersteni and the first occurrence of the ammonoid Paracochloceras suessi in the Steinbergkogel section (Austria), Global Stratotype Section and Point (GSSP) candidate for the Norian–Rhaetian boundary. The appearance of the coccolith Crucirhabdus minutus is seen as a robust biochronological datum that will provide useful constraints for Triassic biostratigraphy, palaeoclimatic modelling and phylogenetic reconstructions. The new calcareous nannofossil biochronology of Steinbergkogel that we present herein completes the existing biostratigraphic characterization of the Norian‐Rhaetian transition based on conodonts and ammonoids and strengthens the position of Steinbergkogel as the best GSSP proposed section for the base of the Rhaetian. The record of coccolithophores across the Norian–Rhaetian boundary at Steinbergkogel takes place along with a discernible increase in abundance of Prinsiosphaera triassica, as well as the appearance of Euconusphaera zlambachensis, which are the two most important Rhaetian pelagic carbonate producers. This succession of bio‐events is interpreted as the initiation of the pelagic carbonate production driven by the successful spreading of calcareous nannofossils in the Western Tethys during the Rhaetian. □Austria, Calcareous Alps, coccolithophores, Triassic.     

Who should Decide for the Unrepresented?

Unrepresented patients lack the capacity to make medical decisions for themselves, have no clear documentation of preferences for medical treatment, and have no surrogate decision maker or obvious candidate for that role. There is no consensus about who should serve as the decision maker for these patients, particularly regarding whether to continue or to limit life‐sustaining treatment. Several authors have argued that ethics committees should play this role rather than the patient's treating physician, a common current default. We argue that concerns about the adequacy of physicians as surrogates are either empirically unfounded or apply equally to ethics committees. We suggest that physicians should be the primary decision maker for the unrepresented because of their fiduciary duties toward their patients. As part of the process of fulfilling these duties, they should seek the advice of third parties such as ethic committees; but final end‐of‐life decision‐making for the unrepresented should rest with the treating physician.     

Priority versus brute force: when should males begin guarding resources?

When should males begin guarding a resource when both resources and guarders vary in quality? This general problem applies, for example, to migrant birds occupying territories in the spring and to precopula in crustaceans where males grab females before they molt and become receptive. Previous work has produced conflicting predictions. Theory on migrant birds predicts that the strongest competitors should often arrive first, whereas some models of mate guarding have predicted that the strongest competitors wait and then simply usurp a female from a weaker competitor. We build a general model of resource guarding that allows varying the ease with which takeovers occur. The model is phrased in terms of mate-guarding crustaceans, but the same logic can be applied to other forms of resource acquisition where priority plays a role but takeovers might be possible too. The race to secure breeding positions can lead to strong competitors (large males) taking females earliest, even though this means accepting a lower-quality female. Paradoxically, this means that small males, which have fewer breeding opportunities, are more choosy than larger ones. Such solutions are found when takeovers are impossible. The easier the takeovers and the higher the rate of finding guarded resources, the more likely are solutions where guarding durations are short, where strong competitors begin guarding only just before breeding, and where they do this by usurping the resource. The relationship between an individual's competitive ability and its timing of resource acquisition can also be nonlinear if takeovers are moderately common; if this is the case, then males of intermediate size guard the longest.