Hasil untuk "Evolution"

M. Bayati, A. Montanari

S. Blomberg, T. Garland, A. Ives

R. Ghanea-Hercock

F. Rohlf, L. Marcus

R. Lande

K. Thelen

M. Andersson, L. Simmons

J. Harborne

Preston Jones, Pragati Pradhan, Douglas Singleton

This paper presents the scenario that gravitational waves, generated in the core collapse of a pre-supernova star, can produce both electromagnetic radiation and sound radiation as gravitational waves propagate outward from the collapsing core. While the energy of this coproduced electromagnetic and sound radiation is orders of magnitude smaller than the initiating gravitational radiation, the power may be sufficient to reignite fusion outside the collapsing core. The nonequilibrium reignition of fusion, in roughly the same time frame as the strongest neutrino emissions, would change the configuration of the pre-supernova star and subsequently the ejecta and the evolution of the stellar expansion of the supernova remnant (SNR). Although the coproduced electromagnetic or sound radiation could not contribute directly to the supernova explosion, the associated nonequilibrium reignition of fusion would alter the state outside the core, leaving an observable signature in the ejecta of the SNR. The aim of this paper is to argue that including this hypothesized coproduced radiation in computational models of core-collapse supernovae would contribute to the evolution of the stellar expansion and consequently should be observable in the SNR, providing a confirmation of the conversion processes for gravitational radiation to electromagnetic and sound radiation.

Aura M. Alonso‐Rodríguez, Pablo E. Gutiérrez‐Fonseca, Scott E. Miller et al.

ABSTRACT Extreme climatic events are expected to increase in frequency and severity under climate change, with lasting consequences for ecological communities worldwide. Global insect declines have raised concerns for biodiversity conservation and ecosystem stability, as shifts in insect communities can trigger cascading effects across trophic levels. Yet insect responses to large‐scale disturbances remain poorly understood, particularly in tropical forests where long‐term datasets are scarce and taxonomic knowledge is limited. We examined the response trajectories and stability of moth communities in two forest types in Puerto Rico following the September 2017 hurricanes Irma and María. Using monthly surveys conducted 5 months before and 6 months after the storms, followed by annual surveys over 5 years, we tracked changes in moth abundance, richness, and composition. We also evaluated ecological stability across multiple dimensions (i.e., resistance, resilience, recovery, and temporal stability) for the entire community and separately for Crambidae, Erebidae, and Geometridae. Despite initial declines, abundance and richness surpassed baseline levels within the first year, especially in old‐growth tabonuco stands, which may have provided more stable microhabitats and resources than palm stands. Resistance varied by family, with grass‐feeding crambids increasing in abundance and arboreal‐feeding geometrids experiencing the greatest species loss. Abundance and richness stabilized within 2 years, likely influenced by trophic interactions that regulated insect outbreaks. Species composition continued to shift over time, reflecting ongoing reassembly, while compositional and functional stability metrics suggested recovery within 5 years. This highlights both the resilience of the moth community and the dynamic nature of post‐disturbance reassembly. Our findings underscore the value of multi‐year, post‐disturbance datasets for uncovering recovery pathways and enhancing our understanding of ecological stability. As extreme events intensify across biomes, insights into resilience dynamics will be critical for sustaining insect biodiversity and the ecological functions they provide.

Lauric Reynes, Louise Fouqueau, D. Aurelle et al.

The impact of climate change on populations will be contingent upon their contemporary adaptive evolution. In this study, we investigated the contemporary evolution of four populations of the cold-water kelp Laminaria digitata by analysing their spatial and temporal genomic variation using ddRAD-sequencing. These populations were sampled from the center to the southern margin of its north-eastern Atlantic distribution at two-time points, spanning at least two generations. Through genome scans for local adaptation at a single time point, we identified candidate loci that showed clinal variation correlated with changes in sea surface temperature (SST) along latitudinal gradients. This finding suggests that SST may drive the adaptive response of these kelp populations, although factors such as species' demographic history should also be considered. Additionally, we performed a simulation approach to distinguish the effect of selection from genetic drift in allele frequency changes over time. This enabled the detection of loci in the southernmost population that exhibited temporal differentiation beyond what would be expected from genetic drift alone: these are candidate loci which could have evolved under selection over time. In contrast, we did not detect any outlier locus based on temporal differentiation in the population from the North Sea, which also displayed low and decreasing levels of genetic diversity. The diverse evolutionary scenarios observed among populations can be attributed to variations in the prevalence of selection relative to genetic drift across different environments. Therefore, our study highlights the potential of temporal genomics to offer valuable insights into the contemporary evolution of marine foundation species facing climate change.

Baptiste Filoche, Stefan Hohenegger

Recent outbreaks of infectious diseases have been monitored closely from an epidemiological and microbiological perspective. Extracting from this wealth of data the information that is relevant for the evolution of the pathogen and predict the further dynamic of the epidemic is a difficult task. We therefore consider clusterings of these data to condense this information. We interpret the relative abundance of (genetic) variants of the pathogen as a time-dependent probability distribution and consider clusterings that keep the Fisher information (approximately) invariant, in order to ensure that they capture the dynamics of the pandemic. By first studying analytic models, we show that this condition groups variants together that interact in a similar fashion with the population and show comparable adaptation to the epidemiological situation. Moreover, we demonstrate that the same clustering can be achieved by grouping variants together according to the time-derivative of their information, which is defined as a function of the probabilities alone. A computationally simple clustering based on the probability distribution therefore allows us to probe interactions of different variants of the pathogen with its environment. To validate these findings, we consider data of 551.459 amino acid sequences of the spike protein of SARS-CoV-2 in France over the course of almost 4 years. We demonstrate that our proposed clustering enables us to identify and track point mutations that allow variants to become dominant and identify temporal correlations among such mutations. We identify indicators which point out dangerous variants, with a potential to grow to large probabilities. We show that we can accurately predict the temporal dynamics of such variants by using a universal model discussed in previous work.

Lia Thomson, Daniel Priego Espinosa, Yaniv Brandvain et al.

Abstract Much research on the evolution of altruism via kin selection, group selection, and reciprocity focuses on the role of a single locus or quantitative trait. Very few studies have explored how linked selection, or selection at loci neighboring an altruism locus, impacts the evolution of altruism. While linked selection can decrease the efficacy of selection at neighboring loci, it might have other effects including promoting selection for altruism by increasing relatedness in regions of low recombination. Here, we used population genetic simulations to study how negative selection at linked loci, or background selection, affects the evolution of altruism. When altruism occurs between full siblings, we found that background selection interfered with selection on the altruistic allele, increasing its fixation probability when the altruistic allele was disfavored and reducing its fixation when the allele was favored. In other words, background selection has the same effect on altruistic genes in family‐structured populations as it does on other, nonsocial, genes. This contrasts with prior research showing that linked selective sweeps can favor the evolution of cooperation, and we discuss possibilities for resolving these contrasting results.

Han-Wei Jiang, Hsiang-Yi Wu, Chun-Hsiung Wang et al.

Abstract Phycobilisomes (PBS) are antenna megacomplexes that transfer energy to photosystems II and I in thylakoids. PBS likely evolved from a basic, inefficient form into the predominant hemidiscoidal shape with radiating peripheral rods. However, it has been challenging to test this hypothesis because ancestral species are generally inaccessible. Here we use spectroscopy and cryo-electron microscopy to reveal a structure of a “paddle-shaped” PBS from a thylakoid-free cyanobacterium that likely retains ancestral traits. This PBS lacks rods and specialized ApcD and ApcF subunits, indicating relict characteristics. Other features include linkers connecting two chains of five phycocyanin hexamers (CpcN) and two core subdomains (ApcH), resulting in a paddle-shaped configuration. Energy transfer calculations demonstrate that chains are less efficient than rods. These features may nevertheless have increased light absorption by elongating PBS before multilayered thylakoids with hemidiscoidal PBS evolved. Our results provide insights into the evolution and diversification of light-harvesting strategies before the origin of thylakoids.

Wenpeng Yang, Chenglu Li, Chenglu Li et al.

This paper reports the first discovery of basic igneous rocks in Bairin Right Banner in southeastern Inner Mongolia, China. To understand the genesis and tectonic evolution of these rocks, we have carried out geochronology and geochemistry research on them. The results show that LA-ICP-MS zircon U-Pb concordant mean ages of massive basalt, diabase, and pillow basalt are 272.0 ± 2.8 Ma, 261.5 ± 3.2 Ma, and 256.5 ± 2.5 Ma, respectively, suggesting their formation during the Late Permian. The massive basalt, diabase, and pillow basalt are tholeiitic with low Mg# values in the ranges of 46.2–66.8, 54.4–71.0, and 53.5–58.2, respectively. They have similar chondrite-normalized rare earth element (REE) patterns. The intensity of REE differentiation is similar to that of typical enriched mid-ocean ridge basalts (E-MORB). The pillow basalts are relatively enriched in Ba and U, while slightly depleted in Rb and Th, and show geochemical affinity to E-MORB. The massive basalts and diabases have the same primitive mantle-normalized patterns and are relatively enriched in Rb, Ba, and U, while depleted in Nb and Ta, similar to the typical island arc magmas. Our new findings indicate that the intra-oceanic subduction of the Paleo-Asian Oceanic slab was still ongoing during the late Permian in the Bairin Right Banner area and, combined with previous studies, it might have been closed during the Late Permian to Early Triassic along the Xar Moron suture zone.

Masaaki Inaba, Eizo Akiyama

We study how expanding the scope for selecting game and learning (adaptation) partners affects the evolution of cooperation in public goods games on scale-free networks. We show the following three results. (i) Expanding the scope for selecting game partners suppresses cooperation. (ii) Expanding the scope for selecting learning partners promotes cooperation when cooperation evolution is difficult. (iii) When cooperation is more likely to evolve, slightly expanding the scope for selecting learning partners causes a significant drop in the cooperation rate, but expanding the scope further causes the cooperation rate to recover. Although (i) is explained by the hub-centered mechanism, the well-known dynamic that promotes cooperation on scale-free networks, (ii) and (iii) are caused by a completely different mechanism that has heretofore been rarely mentioned.

Peng Liu, Yanyan Zheng

This work systematically conducts a data analysis based on the numbers of both cumulative and daily confirmed COVID-19 cases and deaths in a time span through April 2020 to June 2022 for over 200 countries around the world. Such research feature aims to reveal the temporal and spatial evolution of the country-level distribution observed in COVID-19 pandemic, and obtains some interesting results as follows. (1) The distributions of the numbers for cumulative confirmed cases and deaths obey power-law in early stages of COVID-19 and stretched exponential function in subsequent course. (2) The distributions of the numbers for daily confirmed cases and deaths obey power-law in early and late stages of COVID-19 and stretched exponential function in middle stages. The crossover region between power-law and stretched exponential behaviour seems to depend on the evolution of "infection" event and "death" event. Such observation implies a kind of important symmetry related to the dynamics process of COVID-19 spreading. (3) The distributions of the normalized numbers for each metric show a temporal scaling behaviour in 2-year period, and are well described by stretched exponential function. The observation of power-law and stretched exponential behaviour in such country-level distributions suggests underlying intrinsic dynamics of a virus spreading process in human interconnected society. And thus it is important for understanding and mathematically modeling the COVID-19 pandemic.

Xiankun Jin, Liping Xu, Yu Xin et al.

State-owned enterprises (SOEs) are both the economic and political bases of the Chinese Communist Party (the Party) and the Chinese state. The overarching principle of SOE reform is to firmly implement the Party’s leadership and the modern enterprise system. This principle creates a political governance system in China’s SOEs—a Party-dominated governance system characterized by Party leadership, state ownership, Party cadre management, Party participation in corporate decision-making, and intra-Party supervision. This survey explains the logic of political governance in China’s SOEs, presents the evolution and current practices of each element of the system, and discusses findings from both academic research and the field.

G. W. Tyler

Logan Chariker, Joel Lebowitz

We investigate the macroscopic time evolution and stationary states of a mean field generalized contact process in $\mathbb{R}^d$. The model is described by a coupled set of nonlinear integral-differential equations. It was inspired by a model of neurons with discrete voltages evolving by a stochastic integrate and fire mechanism. We obtain a complete solution in the spatially uniform case and partial solutions in the general case. The system has one or more fixed points and also traveling wave solutions.