Ecological opportunity and predator–prey interactions: linking eco-evolutionary processes and diversification in adaptive radiations

Much of life's diversity has arisen through ecological opportunity and adaptive radiations, but the mechanistic underpinning of such diversification is not fully understood. Competition and predation can affect adaptive radiations, but contrasting theoretical and empirical results show that they can both promote and interrupt diversification. A mechanistic understanding of the link between microevolutionary processes and macroevolutionary patterns is thus needed, especially in trophic communities. Here, we use a trait-based eco-evolutionary model to investigate the mechanisms linking competition, predation and adaptive radiations. By combining available micro-evolutionary theory and simulations of adaptive radiations we show that intraspecific competition is crucial for diversification as it induces disruptive selection, in particular in early phases of radiation. The diversification rate is however decreased in later phases owing to interspecific competition as niche availability, and population sizes are decreased. We provide new insight into how predation tends to have a negative effect on prey diversification through decreased population sizes, decreased disruptive selection and through the exclusion of prey from parts of niche space. The seemingly disparate effects of competition and predation on adaptive radiations, listed in the literature, may thus be acting and interacting in the same adaptive radiation at different relative strength as the radiation progresses.

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Moving Songs

The Oxford Handbook of Musical Repatriation ◽

10.1093/oxfordhb/9780190659806.013.42 ◽

2019 ◽

pp. 590-606

Author(s):

Sally Treloyn ◽

Matthew Dembal Martin ◽

Rona Goonginda Charles

Keyword(s):

Cultural Heritage ◽

Knowledge Transmission ◽

Intercultural Relationships ◽

Cultural Negotiation ◽

Intercultural Collaboration ◽

Present Collection ◽

Intergenerational Knowledge ◽

Early Phases ◽

Insight Into

Repatriation has become almost ubiquitous in ethnomusicological research on Australian Indigenous song. This article provides insights into processes of a repatriation-centered song revitalization project in the Kimberley, northwest Australia. Authored by an ethnomusicologist and two members of the Ngarinyin cultural heritage community, the article provides firsthand accounts of the early phases of a long-term repatriation-centered project referred to locally as the Junba Project. The authors provide a sample of narratives and dialogues that deliver insight into experiences of the work of identifying recordings “in the archive” and cultural negotiation and use of recordings “on Country.” The entanglement of local epistemological frameworks with past and present collection, archival research, repatriation, and dissemination for intergenerational knowledge transmission between spirits, Country, and the living, is explored, showing how recordings move song knowledge from community to archive to community and from generation to generation, and move people in present-day communities. The chapter considers how these “moving songs” allow an interrogation of the fraught endeavor of intercultural collaboration in the pursuit of revitalizing Indigenous song traditions. It positions repatriation as a method that can support intergenerational knowledge transmission and as a method to consider past and present intercultural relationships within research projects and between cultural heritage communities and collecting institutions.

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The Impact of Health Policies and Sociodemographic Factors on Doubling Time of the COVID-19 Pandemic in Mexico

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18052354 ◽

2021 ◽

Vol 18 (5) ◽

pp. 2354

Author(s):

Lina Díaz-Castro ◽

Héctor Cabello-Rangel ◽

Kurt Hoffman

Keyword(s):

Population Density ◽

Doubling Time ◽

Sociodemographic Factors ◽

Health Policies ◽

Government Response ◽

University Of Oxford ◽

Negative Effect ◽

Population Sizes ◽

The University ◽

The Impact

Background. The doubling time is the best indicator of the course of the current COVID-19 pandemic. The aim of the present investigation was to determine the impact of policies and several sociodemographic factors on the COVID-19 doubling time in Mexico. Methods. A retrospective longitudinal study was carried out across March–August, 2020. Policies issued by each of the 32 Mexican states during each week of this period were classified according to the University of Oxford Coronavirus Government Response Tracker (OxCGRT), and the doubling time of COVID-19 cases was calculated. Additionally, variables such as population size and density, poverty and mobility were included. A panel data model was applied to measure the effect of these variables on doubling time. Results. States with larger population sizes issued a larger number of policies. Delay in the issuance of policies was associated with accelerated propagation. The policy index (coefficient 0.60, p < 0.01) and the income per capita (coefficient 3.36, p < 0.01) had a positive effect on doubling time; by contrast, the population density (coefficient −0.012, p < 0.05), the mobility in parks (coefficient −1.10, p < 0.01) and the residential mobility (coefficient −4.14, p < 0.01) had a negative effect. Conclusions. Health policies had an effect on slowing the pandemic’s propagation, but population density and mobility played a fundamental role. Therefore, it is necessary to implement policies that consider these variables.

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Functional genomics study of Pseudomonas putida to determine traits associated with avoidance of a myxobacterial predator

Scientific Reports ◽

10.1038/s41598-021-96046-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shukria Akbar ◽

D. Cole Stevens

Keyword(s):

Pseudomonas Putida ◽

Bacterial Communities ◽

Predator Avoidance ◽

Phenotypic Diversity ◽

Myxococcus Xanthus ◽

Predator Prey ◽

Mucoid Conversion ◽

Small Colony ◽

Predator Prey Models ◽

Insight Into

AbstractPredation contributes to the structure and diversity of microbial communities. Predatory myxobacteria are ubiquitous to a variety of microbial habitats and capably consume a broad diversity of microbial prey. Predator–prey experiments utilizing myxobacteria have provided details into predatory mechanisms and features that facilitate consumption of prey. However, prey resistance to myxobacterial predation remains underexplored, and prey resistances have been observed exclusively from predator–prey experiments that included the model myxobacterium Myxococcus xanthus. Utilizing a predator–prey pairing that instead included the myxobacterium, Cystobacter ferrugineus, with Pseudomonas putida as prey, we observed surviving phenotypes capable of eluding predation. Comparative transcriptomics between P. putida unexposed to C. ferrugineus and the survivor phenotype suggested that increased expression of efflux pumps, genes associated with mucoid conversion, and various membrane features contribute to predator avoidance. Unique features observed from the survivor phenotype when compared to the parent P. putida include small colony variation, efflux-mediated antibiotic resistance, phenazine-1-carboxylic acid production, and increased mucoid conversion. These results demonstrate the utility of myxobacterial predator–prey models and provide insight into prey resistances in response to predatory stress that might contribute to the phenotypic diversity and structure of bacterial communities.

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The impact of large terrestrial carnivores on Pleistocene ecosystems

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1502554112 ◽

2015 ◽

Vol 113 (4) ◽

pp. 862-867 ◽

Cited By ~ 49

Author(s):

Blaire Van Valkenburgh ◽

Matthew W. Hayward ◽

William J. Ripple ◽

Carlo Meloro ◽

V. Louise Roth

Keyword(s):

Prey Size ◽

Habitat Degradation ◽

Terrestrial Ecosystems ◽

Growth Data ◽

Predator Prey ◽

Body Sizes ◽

Population Sizes ◽

Potential Impact ◽

The Impact ◽

Ground Sloths

Large mammalian terrestrial herbivores, such as elephants, have dramatic effects on the ecosystems they inhabit and at high population densities their environmental impacts can be devastating. Pleistocene terrestrial ecosystems included a much greater diversity of megaherbivores (e.g., mammoths, mastodons, giant ground sloths) and thus a greater potential for widespread habitat degradation if population sizes were not limited. Nevertheless, based on modern observations, it is generally believed that populations of megaherbivores (>800 kg) are largely immune to the effects of predation and this perception has been extended into the Pleistocene. However, as shown here, the species richness of big carnivores was greater in the Pleistocene and many of them were significantly larger than their modern counterparts. Fossil evidence suggests that interspecific competition among carnivores was relatively intense and reveals that some individuals specialized in consuming megaherbivores. To estimate the potential impact of Pleistocene large carnivores, we use both historic and modern data on predator–prey body mass relationships to predict size ranges of their typical and maximum prey when hunting as individuals and in groups. These prey size ranges are then compared with estimates of juvenile and subadult proboscidean body sizes derived from extant elephant growth data. Young proboscideans at their most vulnerable age fall within the predicted prey size ranges of many of the Pleistocene carnivores. Predation on juveniles can have a greater impact on megaherbivores because of their long interbirth intervals, and consequently, we argue that Pleistocene carnivores had the capacity to, and likely did, limit megaherbivore population sizes.

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Evolution in the cold

Antarctic Science ◽

10.1017/s0954102000000316 ◽

2000 ◽

Vol 12 (3) ◽

pp. 257-257 ◽

Cited By ~ 6

Author(s):

Andrew Clarke

Keyword(s):

Evolutionary Biology ◽

Antarctic Fish ◽

The Arctic ◽

Polar Regions ◽

Evolutionary Studies ◽

Adaptive Radiations ◽

The Antarctic ◽

The Impact ◽

Insight Into

Theodosius Dobzhansky once remarked that nothing in biology makes sense other than in the light of evolution, thereby emphasising the central role of evolutionary studies in providing the theoretical context for all of biology. It is perhaps surprising then that evolutionary biology has played such a small role to date in Antarctic science. This is particularly so when it is recognised that the polar regions provide us with an unrivalled laboratory within which to undertake evolutionary studies. The Antarctic exhibits one of the classic examples of a resistance adaptation (antifreeze peptides and glycopeptides, first described from Antarctic fish), and provides textbook examples of adaptive radiations (for example amphipod crustaceans and notothenioid fish). The land is still largely in the grip of major glaciation, and the once rich terrestrial floras and faunas of Cenozoic Gondwana are now highly depauperate and confined to relatively small patches of habitat, often extremely isolated from other such patches. Unlike the Arctic, where organisms are returning to newly deglaciated land from refugia on the continental landmasses to the south, recolonization of Antarctica has had to take place by the dispersal of propagules over vast distances. Antarctica thus offers an insight into the evolutionary responses of terrestrial floras and faunas to extreme climatic change unrivalled in the world. The sea forms a strong contrast to the land in that here the impact of climate appears to have been less severe, at least in as much as few elements of the fauna show convincing signs of having been completely eradicated.

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Evolution to alternative levels of stable diversity leaves areas of niche space unexplored

10.1101/2021.01.06.425548 ◽

2021 ◽

Author(s):

Ilan N. Rubin ◽

Iaroslav Ispolatov ◽

Michael Doebeli

Keyword(s):

Evolutionary Dynamics ◽

Natural Populations ◽

Metastable States ◽

Community Diversity ◽

Limited Resources ◽

Niche Space ◽

Stable States ◽

Low Diversity ◽

Population Sizes ◽

Adaptive Radiations

AbstractOne of the oldest and most persistent questions in ecology and evolution is whether natural communities tend to evolve toward saturation and maximal diversity. Robert MacArthur’s classical theory of niche packing and the theory of adaptive radiations both imply that populations will diversify and fully partition any available niche space. However, the saturation of natural populations is still very much an open area of debate and investigation. Additionally, recent evolutionary theory suggests the existence of alternative evolutionary stable states (ESSs), which implies that some stable communities may not be fully saturated. Using models with classical Lokta-Volterra ecological dynamics and three formulations of evolutionary dynamics (a model using adaptive dynamics, an individual-based model, and a partial differential equation model), we show that following an adaptive radiation, communities can often get stuck in low diversity states when limited by mutations of small phenotypic effect. These low diversity metastable states can also be maintained by limited resources and finite population sizes. When small mutations and finite populations are considered together, it is clear that despite the presence of higher-diversity stable states, natural populations are likely not fully saturating their environment and leaving potential niche space unfilled. Additionally, within-species variation can further reduce community diversity from levels predicted by models that assume species-level homogeneity.Author summaryUnderstanding if and when communities evolve to saturate their local environments is imperative to our understanding of natural populations. Using computer simulations of classical evolutionary models, we study whether adaptive radiations tend to lead toward saturated communities in which no new species can invade or remain trapped in alternative, lower diversity stable states. We show that with asymmetric competition and small effect mutations, evolutionary Red Queen dynamics can trap communities in low diversity metastable states. Moreover, limited resources not only reduces community population sizes, but also reduces community diversity, denying the formation of saturated communities and stabilizing low diversity, non-stationary evolutionary dynamics. Our results are directly relevant to the longstanding questions important to both ecological empiricists and theoreticians on the species packing and saturation of natural environments. Also, by showing the ease evolution can trap communities in low diversity metastable stats, we demonstrate the potential harm in relying solely on ESSs to answer questions of biodiversity.

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Polygenic local adaptation in metapopulations: a stochastic eco-evolutionary model

10.1101/2020.06.16.154245 ◽

2020 ◽

Author(s):

Enikő Szép ◽

Himani Sachdeva ◽

Nick Barton

Keyword(s):

Population Size ◽

Local Adaptation ◽

Genetic Drift ◽

Diffusion Approximation ◽

Joint Distribution ◽

Evolutionary Model ◽

Ecological Niches ◽

Demographic Stochasticity ◽

Linkage Disequilibria ◽

Population Sizes

AbstractThis paper analyses the conditions for local adaptation in a metapopulation with infinitely many islands under a model of hard selection, where population size depends on local fitness. Each island belongs to one of two distinct ecological niches or habitats. Fitness is influenced by an additive trait which is under habitat-dependent directional selection. Our analysis is based on the diffusion approximation and accounts for both genetic drift and demographic stochasticity. By neglecting linkage disequilibria, it yields the joint distribution of allele frequencies and population size on each island. We find that under hard selection, the conditions for local adaptation in a rare habitat are more restrictive for more polygenic traits: even moderate migration load per locus at very many loci is sufficient for population sizes to decline. This further reduces the efficacy of selection at individual loci due to increased drift and because smaller populations are more prone to swamping due to migration, causing a positive feedback between increasing maladaptation and declining population sizes. Our analysis also highlights the importance of demographic stochasticity, which exacerbates the decline in numbers of maladapted populations, leading to population collapse in the rare habitat at significantly lower migration than predicted by deterministic arguments.

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Universal Evolutionary Model for Periodical Species

Complexity ◽

10.1155/2021/2976351 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Eric Goles ◽

Ivan Slapničar ◽

Marco A. Lardies

Keyword(s):

Fitness Function ◽

Evolutionary Model ◽

Prime Numbers ◽

Life Cycles ◽

The Other ◽

Exclusion Principle ◽

Greatest Common Divisor ◽

Predator Prey ◽

Integer Multiple ◽

New Period

Real-world examples of periodical species range from cicadas, whose life cycles are large prime numbers, like 13 or 17, to bamboos, whose periods are large multiples of small primes, like 40 or even 120. The periodicity is caused by interaction of species, be it a predator-prey relationship, symbiosis, commensalism, or competition exclusion principle. We propose a simple mathematical model, which explains and models all those principles, including listed extremal cases. This rather universal, qualitative model is based on the concept of a local fitness function, where a randomly chosen new period is selected if the value of the global fitness function of the species increases. Arithmetically speaking, the different interactions are related to only four principles: given a couple of integer periods either (1) their greatest common divisor is one, (2) one of the periods is prime, (3) both periods are equal, or (4) one period is an integer multiple of the other.

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Deformation Effect on Water Transport through Nanotubes

Energies ◽

10.3390/en12234424 ◽

2019 ◽

Vol 12 (23) ◽

pp. 4424 ◽

Cited By ~ 2

Author(s):

Robinson ◽

Shahbabaei ◽

Kim

Keyword(s):

Molecular Dynamics ◽

Water Transport ◽

Boron Nitride Nanotubes ◽

Fickian Diffusion ◽

Deformation Effect ◽

Degree Of Deformation ◽

Single File ◽

Negative Effect ◽

Non Equilibrium Molecular Dynamics ◽

Insight Into

In this study, we used non-equilibrium molecular dynamics to study the transport of water through deformed (6,6) Carbon Nanotubes (CNTs) and Boron Nitride Nanotubes (BNNTs). The results were then compared with that of the perfect nanotubes. The main aim of this study was to get a better insight into the deformation effect on water transport through nanotubes rather than directly comparing the CNTs and BNNTs. As the diameters of both types of nanotubes differ from each other for the same chiral value, they are not directly comparable. We carried out our study on deformations such as screw distortion, XY-distortion, and Z-distortion. XY-distortion of value 2 shows a change from single-file water transport to near-Fickian diffusion. The XY-distortions of higher value shows a notable negative effect on water transport when their distortion values get larger. These suggest that the degree of deformation plays a crucial role in water transport through deformed nanotubes. The Z-distortion of 2 showed discontinuous single-file chain formation inside the nanotubes. Similar phenomena are observed in both nanotubes, irrespective of their type, while the magnitudes of their effects vary.

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Exquisitely Preserved Fossil Snakes of Messel: Insight into the Evolution, Biogeography, Habitat Preferences and Sensory Ecology of Early Boas

Diversity ◽

10.3390/d12030100 ◽

2020 ◽

Vol 12 (3) ◽

pp. 100 ◽

Cited By ~ 2

Author(s):

Agustín Scanferla ◽

Krister T. Smith

Keyword(s):

Body Size ◽

New World ◽

Middle Eocene ◽

Habitat Preferences ◽

Sensory Ecology ◽

Morphological Diversity ◽

Predator Prey ◽

Upper Jaw ◽

Spectrum Evaluation ◽

Insight Into

Our knowledge of early evolution of snakes is improving, but all that we can infer about the evolution of modern clades of snakes such as boas (Booidea) is still based on isolated bones. Here, we resolve the phylogenetic relationships of Eoconstrictor fischeri comb. nov. and other booids from the early-middle Eocene of Messel (Germany), the best-known fossil snake assemblage yet discovered. Our combined analyses demonstrate an affinity of Eoconstrictor with Neotropical boas, thus entailing a South America-to-Europe dispersal event. Other booid species from Messel are related to different New World clades, reinforcing the cosmopolitan nature of the Messel booid fauna. Our analyses indicate that Eoconstrictor was a terrestrial, medium- to large-bodied snake that bore labial pit organs in the upper jaw, the earliest evidence that the visual system in snakes incorporated the infrared spectrum. Evaluation of the known palaeobiology of Eoconstrictor provides no evidence that pit organs played a role in the predator–prey relations of this stem boid. At the same time, the morphological diversity of Messel booids reflects the occupation of several terrestrial macrohabitats, and even in the earliest booid community the relation between pit organs and body size is similar to that seen in booids today.

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