Evolutionary paths to macrolide resistance in a Neisseria commensal converge on ribosomal genes through short sequence duplications

Neisseria commensals are an indisputable source of resistance for their pathogenic relatives. However, the evolutionary paths commensal species take to reduced susceptibility in this genus have been relatively underexplored. Here, we leverage in vitro selection as a powerful screen to identify the genetic adaptations that produce azithromycin resistance (≥ 2 μg/mL) in the Neisseria commensal, N. elongata. Across multiple lineages (n = 7/16), we find mutations that reduce susceptibility to azithromycin converge on the locus encoding the 50S ribosomal L34 protein (rpmH) and the intergenic region proximal to the 30S ribosomal S3 protein (rpsC) through short tandem duplication events. Interestingly, one of the laboratory evolved mutations in rpmH is identical (7LKRTYQ12), and two nearly identical, to those recently reported to contribute to high-level azithromycin resistance in N. gonorrhoeae. Transformations into the ancestral N. elongata lineage confirmed the causality of both rpmH and rpsC mutations. Though most lineages inheriting duplications suffered in vitro fitness costs, one variant showed no growth defect, suggesting the possibility that it may be sustained in natural populations. Ultimately, studies like this will be critical for predicting commensal alleles that could rapidly disseminate into pathogen populations via allelic exchange across recombinogenic microbial genera.

Born brothers, born global: multiple possible faces of the internationalization path

Purpose Operating in a variety of countries, multinational companies (MNCs) experience a high variety and variability of physiological and contextual dynamics, requiring a more careful knowledge management approach. In this scenario, this paper aims to investigate the entrepreneurial facets and managerial aspects (entrepreneurial orientation/managerial intentionality) of MNCs’ internationalization from a knowledge-based perspective. Design/methodology/approach A theory-building approach is applied, involving a comparative case study of two MNCs conceived through the separation of a unique family business. Aiming to enrich the research about companies’ internationalization, some crucial elements are individuated to build a theoretical frame explaining the evolutionary paths of so-called born global. Findings This paper shows that companies’ internationalization development is based on a multiplicity of variables and underlines the need to incorporate different points of view when attempting to explain the dynamics of internationalization processes. Research limitations/implications The empirical significance of the two cases does not legitimize theorization. However, this research presents interesting results that could be strengthened by a series of comparative case studies dealing with other MNCs or deeper quantitative investigation. Originality/value This research approach could be considered as stimulating by the scientific and managerial community, as the internationalization process is articulated by mixing managerial, entrepreneurial and cognitive aspects.

The Remarkable Evolutionary Plasticity of Coronaviruses by Mutation and Recombination: Insights for the COVID-19 Pandemic and the Future Evolutionary Paths of SARS-CoV-2

Coronaviruses (CoVs) constitute a large and diverse subfamily of positive-sense single-stranded RNA viruses. They are found in many mammals and birds and have great importance for the health of humans and farm animals. The current SARS-CoV-2 pandemic, as well as many previous epidemics in humans that were of zoonotic origin, highlights the importance of studying the evolution of the entire CoV subfamily in order to understand how novel strains emerge and which molecular processes affect their adaptation, transmissibility, host/tissue tropism, and patho non-homologous genicity. In this review, we focus on studies over the last two years that reveal the impact of point mutations, insertions/deletions, and intratypic/intertypic homologous and non-homologous recombination events on the evolution of CoVs. We discuss whether the next generations of CoV vaccines should be directed against other CoV proteins in addition to or instead of spike. Based on the observed patterns of molecular evolution for the entire subfamily, we discuss five scenarios for the future evolutionary path of SARS-CoV-2 and the COVID-19 pandemic. Finally, within this evolutionary context, we discuss the recently emerged Omicron (B.1.1.529) VoC.

Evolution of brilliant iridescent feather nanostructures

The brilliant iridescent plumage of birds creates some of the most stunning color displays known in the natural world. Iridescent plumage colors are produced by nanostructures in feathers and have evolved in diverse birds. The building blocks of these structures—melanosomes (melanin-filled organelles)—come in a variety of forms, yet how these different forms contribute to color production across birds remains unclear. Here, we leverage evolutionary analyses, optical simulations, and reflectance spectrophotometry to uncover general principles that govern the production of brilliant iridescence. We find that a key feature that unites all melanosome forms in brilliant iridescent structures is thin melanin layers. Birds have achieved this in multiple ways: by decreasing the size of the melanosome directly, by hollowing out the interior, or by flattening the melanosome into a platelet. The evolution of thin melanin layers unlocks color-producing possibilities, more than doubling the range of colors that can be produced with a thick melanin layer and simultaneously increasing brightness. We discuss the implications of these findings for the evolution of iridescent structures in birds and propose two evolutionary paths to brilliant iridescence.

Mutational analysis of SARS-CoV-2. ORF8 and the evolution of the Delta and Omicron variants.

SARS-CoV-2 the virus responsible for the current pandemic. This virus is continually evolving, adapting to both innate and acquired immune responses and therapeutic drugs. Therefore, it is important to understand how the virus evolving to design the appropriate therapeutic and vaccine in preparation for future variants. Here, we used the online SARS-CoV-2 databases, Nextstrain and Ourworld, to map the evolution and epidemiology of the virus. We identified 30 high entropy residues which underwent a progressive evolution to arrive at the current dominant variant - Delta variant. The virus underwent mutational waves with the first wave made up of structural proteins important in its infectivity and the second wave made up of the ORFs important for its contagion. The most important driver of the second wave is ORF8 mutations at residue 119 and 120. Further mutations of these two residues are creating new clades that are offshoots from the Delta backbone. More importantly the further expansion of the S protein in the Omicron variant is now followed with the acquisition of ORF8 mutations 119 and 120. These findings demonstrate how SARS-CoV-2 mutates and points to two evolutionary paths; 1) Mutational expansion on the Delta backbone among the ORFs and 2) Mutational expansion of the S protein on other backbone follow with mutational wave among the ORFs. Both are happening at the same time right now with the Omicron variant early in the first wave to follow with a more aggressive second wave of mutations.

On reappearance and complexity in musical calling

Music is especially valued in human societies, but music-like behavior in the form of song also occurs in a variety of other animal groups including primates. The calling of our primate ancestors may well have evolved into the music of modern humans via multiple selective scenarios. But efforts to uncover these influences have been hindered by the challenge of precisely defining musical behavior in a way that could be more generally applied across species. We propose an acoustic focused reconsideration of “musicality” that could help enable independent inquiry into potential ecological pressures on the evolutionary emergence of such behavior. Using published spectrographic images (n = 832 vocalizations) from the primate vocalization literature, we developed a quantitative formulation that could be used to help recognize signatures of human-like musicality in the acoustic displays of other species. We visually scored each spectrogram along six structural features from human music—tone, interval, transposition, repetition, rhythm, and syllabic variation—and reduced this multivariate assessment into a concise measure of musical patterning, as informed by principal components analysis. The resulting acoustic reappearance diversity index (ARDI) estimates the number of different reappearing syllables within a call type. ARDI is in concordance with traditional measures of bird song complexity yet more readily identifies shorter, more subtly melodic primate vocalizations. We demonstrate the potential utility of this index by using it to corroborate several origins scenarios. When comparing ARDI scores with ecological features, our data suggest that vocalizations with diversely reappearing elements have a pronounced association with both social and environmental factors. Musical calls were moderately associated with wooded habitats and arboreal foraging, providing partial support for the acoustic adaptation hypothesis. But musical calling was most strongly associated with social monogamy, suggestive of selection for constituents of small family-sized groups by neighboring conspecifics. In sum, ARDI helps construe musical behavior along a continuum, accommodates non-human musicality, and enables gradualistic co-evolutionary paths between primate taxa—ranging from the more inhibited locational calls of archaic primates to the more exhibitional displays of modern apes.

Self-conscious intelligent technological societies in the universe: a simple direct approach to probable astrosociological realistic scenarios

We present an alternative equation to estimate the probable number N of self-conscious intelligent technological societies (SCITSs) within the radius of the observable universe. This equation has only one poorly-known factor, Pc, the SCITS's formation probability, which can be estimated within an uncertainty by a factor of 102 (10−11 ≤ Pc ≤ 10−9) by applying the restriction imposed by Fermi's Paradox. The SCITS's formation rate for a typical spiral galaxy is then estimated as ≈1 civ Gyr−1. For a very optimistic maximum life expectancy ≈108 yr, the conclusion is that two civilizations never coexist in the same galaxy. Our estimated values for Pc are compatible with current biological and astrophysical evidences. We also propose an alternative astrosociological classification scheme which enables us to speculate about possible evolutionary paths for SCITSs in the universe. The so-called ‘Closed Bottle Neck’ (CBN) scenario suggests that civilizations are no exit evolutionary ways. We argue that simply there would not be interstellar travels nor Galaxy colonization or a Galactic Club. Thus Fermi's Paradox results eliminated, and the perspectives about the future of our own civilization may not be positive.

The Mechanism of Evolution and Balance for e-Commerce Ecosystem under Blockchain

With the development of society, e-commerce competition has become increasingly intense and has ascended to the level of the ecosystem. Therefore, it is extremely significant to study the mechanism of evolution and balance for the e-commerce ecosystem. Simultaneously, blockchain technology is essentially a consensus mechanism, the core idea of which is decentralization, but it is actually the deconstruction of privileges and authority. Especially, the influence on the e-commerce ecosystem cannot be underestimated. Blockchain technology ultimately changes not only technology, but a comprehensive reconstruction of various industries. Building an e-commerce information ecosystem based on blockchain can promote the healthy and sustainable development of e-commerce information ecology. This work combines the definition and technical characteristics of blockchain, discusses the blockchain-based e-commerce information ecosystem model, and discusses how to achieve the ecological balance and system evolution of e-commerce under the background of blockchain. According to the internal problems of the e-commerce ecosystem, three evolutionary paths are proposed in this work. First, consider the timeliness of the information and construct a full-process information channel. Second, remove central nodes and build a safe and efficient block payment. Third, solve the blind zone in the field of logistics and create efficient and transparent intelligent logistics. This work can provide an effective reference for the development of e-commerce.

Karyotype Diversity, Mode, and Tempo of the Chromosomal Evolution of Attina (Formicidae: Myrmicinae: Attini): Is There an Upper Limit to Chromosome Number?

Ants are an important insect group that exhibits considerable diversity in chromosome numbers. Some species show only one chromosome, as in the males of the Australian bulldog ant Myrmecia croslandi, while some have as many as 60 chromosomes, as in the males of the giant Neotropical ant Dinoponera lucida. Fungus-growing ants are a diverse group in the Neotropical ant fauna, engaged in a symbiotic relationship with a basidiomycete fungus, and are widely distributed from Nearctic to Neotropical regions. Despite their importance, new chromosome counts are scarcely reported, and the marked variation in chromosome number across species has been poorly studied under phylogenetic and genome evolutionary contexts. Here, we present the results of the cytogenetic examination of fungus-farming ants and compile the cytogenetic characteristics and genome size of the species studied to date to draw insights regarding the evolutionary paths of karyotype changes and diversity. These data are coupled with a fossil-calibrated phylogenetic tree to discuss the mode and tempo of chromosomal shifting, considering whether there is an upper limit for chromosome number and genome size in ants, using fungus-farming ants as a model study. We recognize that karyotypes are generally quite variable across fungus-farming ant phylogeny, mostly between genera, and are more numerically conservative within genera. A low chromosome number, between 10 and 12 chromosomes, seems to present a notable long-term evolutionary stasis (intermediate evolutionary stasis) in fungus-farming ants. All the genome size values were inside a limited spectrum below 1 pg. Eventual departures in genome size occurred with regard to the mean of 0.38 pg, indicating that there is a genome, and likely a chromosome, number upper limit.