Michael P. Gillman’s research while affiliated with The Open University and other places

Forecasting trends in COVID-19 infections is vital for global economies, political structures and physical and mental human well-being. Using the per capita number of new cases as a proxy for the abundance of the SARS-CoV-2 virus, and the number of deaths as a measure of virulence, the dynamics of the pandemic and the outcomes emerging from it are examined for three locations (England, Italy and New York State). The data are analysed with a new version of a model which allows straightforward estimation of key parameters. The results are seen to be consistent with coevolutionary perspectives on shifts from natural hosts such as bats to alternate hosts such as humans, encompassing either local extinction of the virus or tendencies to very low abundance. The parameters of the model are contrasted with standard epidemiological models and interpreted with respect to biological processes and isolation policies.

Forecasting trends in COVID-19 infections is vital for the global economy, national governments and physical and mental well-being. Using the per capita number of new cases as a proxy for the abundance of the SARS-CoV-2 virus, and the number of deaths as a measure of virulence, the dynamics of the pandemic and the outcomes emerging from it are examined for three locations (England, Italy and New York State). The data are analysed with a new version of a population dynamics model that combines exponential/logistic growth with time-varying carrying capacity, allowing predictions of persistence or extinction of the virus. In agreement with coevolutionary theory, the model suggests a transition from exponential virus growth to low abundance, coupled with reduced virulence, during colonisation of the alternate human host. The structure of the model allows a straightforward assessment of key parameters, which can be contrasted with standard epidemiological models and interpreted with respect to ecological and evolutionary processes and isolation policies.

Insect pollinators face a number of well-documented threats that challenge their survival at an individual and community level. The effect of extreme events on pollinator assemblages has received little attention to date, partly due to a lack of consensus on what constitutes extreme, but also because robust pre-event data is often lacking. Here, the term SHOCK (Sudden, High-magnitude Opportunity for a Catastrophic 'Kick') is used to encompass attributes of extreme events that carry the potential to add additional challenges to insect communities already facing environmental stressors. Selected events from two SHOCK categories are explored (those with natural origins and those that are human-mediated). The value of studying single events is considered in the context of a third category; human-enhanced SHOCKs.

The passage of our Solar System through the spiral arms has been implicated as a contributor to global environmental perturbations. The suggestion of a consistent structure within the arms, informed by density wave theory, raises the possibility of repeating patterns of events at each arm crossing. Here we test the hypothesis that the structure of the arms of our galaxy influences the stratigraphic record on Earth. We construct independent structural and temporal models and combine these to compare the timings of arm tracers, materials from the earliest Solar System and events on Earth, including the largest extinctions. We find that a recurring sequence of events across the four arms emerges with an average arm-passing time of 188 million years. We suggest that the multiple temporal overlaps of events across arms, and their alignment with arm tracers and the earliest Solar System, presents an opportunity for a greater understanding of both Earth-based phenomena and galactic structure.

High-density regions within the spiral arms are expected to have profound effects on passing stars. Understanding of the potential effects on the Earth and our Solar System is dependent on a robust model of arm passage dynamics. Using a novel combination of data, we derive a model of the timings of the Solar System through the spiral arms and the relationship to arm tracers such as methanol masers. This reveals that asteroid/comet impacts are significantly clustered near the spiral arms and within specific locations of an average arm structure. The end-Permian and end-Cretaceous extinctions emerge as being located within a small star-formation region in two different arms. The start of the Solar System, greater than 4.5 Ga, occurs in the same region in a third arm. The model complements geo-chemical data in determining the relative importance of extra-Solar events in the diversification and extinction of life on Earth.

Ground-nesting bees use a variety of substrates in which to establish cells and complete their reproductive cycles. Here we document the highly aberrant occurrence of a solitary bee species, Anthophora squammulosa Dours, 1870 (Hymenoptera: Apidae: Anthophorini), nesting within meters of an active volcanic crater in Nicaragua, Central America. The nest location is exposed to continuous, strongly acidic gas emissions (>2.7 ppm of SO2), and sporadic vent clearing episodes that blanket the surrounding area with ash and tephra. An assessment of floral resources available within the expected homing distance of the species was cross-referenced with pollen carried by females returning to their nests. At this site, A. squammulosa appears to forage almost exclusively on a single plant, Melanthera nivea (L.) Small, 1903 (Asteraceae), that is adapted to volcanic acidic rain, despite being widely accepted as a generalist bee in the remainder of its range. Notwithstanding the extreme nature of the site, and the co-occurrence of specialist natural enemies and predators, the possibility exists that the site is selected for its beneficial attributes, such as the loose, well-drained substrate and the absence of vegetation. The converse is that the site is sub-optimal with the population constrained by habitat patchiness and limited dispersal options.

Globally disruptive events include asteroid/comet impacts, large igneous provinces and glaciations, all of which have been considered as contributors to mass extinctions. Understanding the overall relationship between the timings of the largest extinctions and their potential proximal causes remains one of science's great unsolved mysteries. Cycles of about 60 Myr in both fossil diversity and environmental data suggest external drivers such as the passage of the Solar System through the galactic plane. While cyclic phenomena are recognized statistically, a lack of coherent mechanisms and a failure to link key events has hampered wider acceptance of multi-million year periodicity and its relevance to earth science and evolution. The generation of a robust predictive model of timings, with a clear plausible primary mechanism, would signal a paradigm shift. Here, we present a model of the timings of globally disruptive events and a possible explanation of their ultimate cause. The proposed model is a symmetrical pattern of 63 Myr sequences around a central value, interpreted as the occurrence of events along, and parallel to, the galactic midplane. The symmetry is consistent with multiple dark matter disks, aligned parallel to the midplane. One implication of the precise pattern of timings and the underlying physical model is the ability to predict future events, such as a major extinction in 1–2 Myr.

A model of cyclical (sinusoidal) motion of the solar system, intercepting event lines distributed at fixed intervals, explains the pattern of timings of mass extinctions, earlier glaciations, largest impact craters and the largest known extrusions of magma in the history of the Earth. The model reveals links between several sets of key events, including the end-Cretaceous and end-Ordovician extinctions with the Marinoan glaciation, and the end-Permian with the end-Serpukhovian extinctions. The model is supported by significant clusters of events and a significant reduction of impact crater size with position (sine value). The pattern of event lines is sustained to the earliest-dated impact craters (2023 and 1849 Ma) and to the origin of the solar system, close to 4567.4 Ma. The implication is that, for the entirety of its existence, the solar system has passed in a consistent manner through a predictably structured galaxy. Dark matter is a possible contender for the structure determining the event lines.

Micropterix calthella L. (Micropterigidae) is a small, day-flying moth from the basal-most extant lineage of the Lepidoptera. The species name reflects its conspicuous presence on Caltha palustris L. (Ranunculaceae). However, adults also favour sedges (Carex spp., Cyperaceae), on which they gather gregariously to feed on pollen and find mates. In a UK ancient wood, the phenology of eight sedge species together with individual moth and mating pair densities were monitored from 15th April to 8th June 2009. 4841 moth sightings were recorded. Moths on Carex spikes at various developmental stages were compared with null models to test for preference patterns. Approximately 99% of individuals selected Carex spikes where dehiscing anthers were present. The sedge phenology data suggest three distinct periods of pollen production. Overlaying this with the moth data reveals moth phenology strongly linked to a suite of early and mid-season woodland sedges. Of the twenty-eight other angiosperm species (seventeen families) in flower, only Ranunculus ficaria L. (Ranunculaceae) and R. repens L. attracted moths. Adult moths kept in captivity on potted Carex flacca Schreb. for 10days laid eggs at the plant-soil interface. When C. flacca pollen production ceased, surviving adults were moved onto freshly dehiscing anthers of potted C. pallescens L., where they survived a further 14days. Soil-dwelling first instar larvae were observed to consume C. sylvatica Huds leaves. In a choice experiment, larvae were significantly more likely to consume C. sylvatica than Stellaria media (L.) Vill. (Caryophyllaceae) leaf material (previously noted to be favoured by larvae). Synchrony between adult moths and Carex spp., and the use of Carex by both adults and larvae, suggests sedges may be host plants for M. calthella in lowland ancient woodlands. Keywords Micropterix calthella -Sedge- Carex -Ancient wood-Micropterigidae-Phenology-Cyperaceae-Lepidoptera