525: Elexacaftor/tezacaftor/ivacaftor therapy alters the CF lung mucus metabolome, reshaping microbiome niche space

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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Impact of urbanization on functional diversity in macromycete communities along an urban ecosystem in Southwest Mexico

PeerJ ◽

10.7717/peerj.12191 ◽

2021 ◽

Vol 9 ◽

pp. e12191

Author(s):

Marko Gómez-Hernández ◽

Emily Avendaño-Villegas ◽

María Toledo-Garibaldi ◽

Etelvina Gándara

Keyword(s):

Species Richness ◽

Functional Diversity ◽

Ecosystem Functioning ◽

Urban Ecosystem ◽

Niche Space ◽

Urbanization Gradient ◽

Urbanization Level ◽

Functional Value ◽

Functional Richness ◽

Available Resources

Macromycetes are a group of fungi characterized by the production of fruit bodies and are highly relevant in most terrestrial ecosystems as pathogens, mutualists, and organic matter decomposers. Habitat transformation can drastically alter macromycete communities and diminish the contribution of these organisms to ecosystem functioning; however, knowledge on the effect of urbanization on macrofungal communities is scarce. Diversity metrics based on functional traits of macromycete species have shown to be valuable tools to predict how species contribute to ecosystem functionality since traits determine the performance of species in ecosystems. The aim of this study was to assess patterns of species richness, functional diversity, and composition of macrofungi in an urban ecosystem in Southwest Mexico, and to identify microclimatic, environmental, and urban factors related to these patterns in order to infer the effect of urbanization on macromycete communities. We selected four oak forests along an urbanization gradient and established a permanent sampling area of 0.1 ha at each site. Macromycete sampling was carried out every week from June to October 2017. The indices used to measure functional diversity were functional richness (FRic), functional divergence (FDig), and functional evenness (FEve). The metric used to assess variation of macrofungal ecological function along the study area was the functional value. We recorded a total of 134 macromycete species and 223 individuals. Our results indicated a decline of species richness with increased urbanization level related mainly to microclimatic variables, and a high turnover of species composition among study sites, which appears to be related to microclimatic and urbanization variables. FRic decreased with urbanization level, indicating that some of the available resources in the niche space within the most urbanized sites are not being utilized. FDig increased with urbanization, which suggests a high degree of niche differentiation among macromycete species within communities in urbanized areas. FEve did not show notable differences along the urbanization gradient, indicating few variations in the distribution of abundances within the occupied sections of the niche space. Similarly, the functional value was markedly higher in the less urbanized site, suggesting greater performance of functional guilds in that area. Our findings suggest that urbanization has led to a loss of macromycete species and a decrease in functional diversity, causing some sections of the niche space to be hardly occupied and available resources to be under-utilized, which could, to a certain extent, affect ecosystem functioning and stability.

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TRIZ Evolution Theory Applied to Man-Made Boards

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.441.1060 ◽

2013 ◽

Vol 441 ◽

pp. 1060-1063

Author(s):

Hui Ling Yu ◽

Hao Liang ◽

De Lin Fan

Keyword(s):

Life Cycle ◽

Technology Development ◽

Evolution Theory ◽

Niche Space ◽

Waste Wood ◽

Term Forecast ◽

Technology Life Cycle ◽

S Curve ◽

Current Stage

Man-made boards often made use of waste wood materials. China is one of the worlds largest manufacturers and consumers of man-made board applications. Application of the law of evolution with a S-shaped curve could contribute essentially to the accuracy of the long-term forecast. This research seeks to determine the current stage and the position on the S-curve of man-made board technology in China on the TRIZ evolution theory and introduce a methodology which combines patent analysis and technology life cycle forecasting to find a niche space of man-made technology development in China.

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Rapid expansion and diversification into new niche space by fluvicoline flycatchers

Journal of Avian Biology ◽

10.1111/jav.01661 ◽

2018 ◽

Vol 49 (3) ◽

pp. jav-01661 ◽

Cited By ~ 1

Author(s):

Jon Fjeldså ◽

Jan I. Ohlson ◽

Henrique Batalha-Filho ◽

Per G. P. Ericson ◽

Martin Irestedt

Keyword(s):

Rapid Expansion ◽

Niche Space

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Sex and occupation time influence niche space of a recovering keystone predator

Ecology and Evolution ◽

10.1002/ece3.4953 ◽

2019 ◽

Vol 9 (6) ◽

pp. 3321-3334 ◽

Cited By ~ 3

Author(s):

Erin U. Rechsteiner ◽

Jane C. Watson ◽

M. Tim Tinker ◽

Linda M. Nichol ◽

Matthew J. Morgan Henderson ◽

...

Keyword(s):

Occupation Time ◽

Niche Space ◽

Keystone Predator

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Caenagnathids of the Dinosaur Park Formation (Campanian) of Alberta, Canada: anatomy, osteohistology, taxonomy, and evolution

Vertebrate Anatomy Morphology Palaeontology ◽

10.18435/vamp29362 ◽

2020 ◽

Vol 8 ◽

pp. 105-153 ◽

Cited By ~ 1

Author(s):

Gregory Funston

Keyword(s):

Body Size ◽

Skeletal Maturity ◽

Niche Overlap ◽

Niche Space ◽

The Past ◽

Adult Body ◽

New Material ◽

Taxonomic Framework ◽

Dinosaur Park Formation ◽

Insight Into

Our understanding of caenagnathid anatomy, diversity, and ecology has improved considerably in the past twenty years, but numerous issues still remain. Among these, the diversity and taxonomy of caenagnathids from the Dinosaur Park Formation of Alberta, Canada, have remained problematic. Whereas some authors recognize three genera, others suggest only two were present, and there is considerable disagreement about which specimens are referable to which genus. This study aims to resolve this issue by reviewing the known specimens and using osteohistology, to establish a testable taxonomic framework of Dinosaur Park Formation caenagnathids. Numerous new specimens from all regions of the skeleton provide insight into morphological variation in caenagnathids, and three morphotypes are recognized based on a combination of morphological features and body size. Osteohistology shows that representatives in each body size class are at skeletal maturity, and therefore supports the delineation of three taxa: the smaller Citipes elegans gen. nov., the intermediate Chirostenotes pergracilis, and the larger Caenagnathus collinsi, new material of which shows it rivalled Anzu wyliei in size. However, these analyses also raise concerns about the referral of isolated material to each taxon in the absence of skeletal overlap between specimens or osteohistological analysis. Caenagnathids are consistently recovered throughout the Dinosaur Park Formation interval, and two geographic clusters of increased abundance probably reflect collection and taphonomic biases. The coexistence of three taxa was apparently facilitated by differences in both adult body size and functional morphology of the dentary and pes, which suggests that caenagnathids minimized niche overlap rather than subdividing niche space. Regardless, little is known of the exact roles caenagnathids played in Late Cretaceous ecosystems. Incorporation of the new material and taxonomic framework into a phylogenetic analysis drastically improves our understanding of the relationships between caenagnathines, and sheds light on the evolution of body size in caenagnathids and its role in their diversification.

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GENETIC LOADS IN HETEROGENEOUS ENVIRONMENTS

Genetics ◽

10.1093/genetics/80.3.621 ◽

1975 ◽

Vol 80 (3) ◽

pp. 621-635

Author(s):

Charles E Taylor

Keyword(s):

Population Structure ◽

Genetic Variation ◽

Gene Frequency ◽

Phase Plane ◽

Genetic Load ◽

Sufficient Conditions ◽

Heterogeneous Environments ◽

Niche Space ◽

Necessary And Sufficient ◽

Existence Of Equilibria

ABSTRACT A model of population structure in heterogeneous environments is described with attention focused on genetic variation at a single locus. The existence of equilibria at which there is no genetic load is examined.—The absolute fitness of any genotype is regarded as a function of location in the niche space and the population density at that location. It is assumed that each organism chooses to live in that habitat in which it is most fit ("optimal habitat selection").—Equilibria at which there is no segregational load ("loadless equilibria") may exist. Necessary and sufficient conditions for the existence of such equilibria are very weak. If there is a sufficient amount of dominance or area in which the alleles are selectively neutral, then there exist equilibria without segregational loads. In the N, p phase plane defined by population size, N, and gene frequency, p, these equilibria generally consist of a line segment which is parallel to the p axis. These equilibria are frequently stable.

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