Can Bacterial Populations Go Extinct? Evolutionary Biology and Bacterial Studies in Cuatro Ciénegas Shed Light on the Extinction Process

2022 ◽  
pp. 143-162
Author(s):  
Manuel II García-Ulloa ◽  
Valeria Souza ◽  
Gabriela Olmedo-Alvarez ◽  
Luis E. Eguiarte
Keyword(s):  
Evolutionary Biology ◽  
Bacterial Populations ◽  
Extinction Process ◽  
Cuatro Ciénegas ◽  
Shed Light

scholarly journals Kin and multilevel selection in social evolution: a never-ending controversy?

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 776 ◽  
Author(s):  
Jos Kramer ◽  
Joël Meunier
Keyword(s):  
Kin Selection ◽  
Group Selection ◽  
Evolutionary Biology ◽  
Social Evolution ◽  
Selection Process ◽  
Structured Populations ◽  
Multilevel Selection ◽  
Current Debate ◽  
The Relationship ◽  
Shed Light

Kin selection and multilevel selection are two major frameworks in evolutionary biology that aim at explaining the evolution of social behaviors. However, the relationship between these two theories has been plagued by controversy for almost half a century and debates about their relevance and usefulness in explaining social evolution seem to rekindle at regular intervals. Here, we first provide a concise introduction into the kin selection and multilevel selection theories and shed light onto the roots of the controversy surrounding them. We then review two major aspects of the current debate: the presumed formal equivalency of the two theories and the question whether group selection can lead to group adaptation. We conclude by arguing that the two theories can offer complementary approaches to the study of social evolution: kin selection approaches usually focus on the identification of optimal phenotypes and thus on the endresult of a selection process, whereas multilevel selection approaches focus on the ongoing selection process itself. The two theories thus provide different perspectives that might be fruitfully combined to promote our understanding of the evolution in group-structured populations.

scholarly journals Geohelminths: public health significance

2014 ◽  
Vol 8 (01) ◽  
pp. 005-016 ◽  
Author(s):  
Suvash Chandra Ojha ◽  
Chayannan Jaide ◽  
Natini Jinawath ◽  
Porpon Rotjanapan ◽  
Pankaj Baral
Keyword(s):  
Public Health ◽  
Evolutionary Biology ◽  
Host Immune System ◽  
Developing Regions ◽  
Diagnostic Features ◽  
Stunted Growth ◽  
Ancylostoma Duodenale ◽  
Health Significance ◽  
Shed Light

The worldwide prevalence of geohelminths and their unique place in evolutionary biology have attracted research focus. These major soil-transmitted intestinal nematodes that cause human diseases are the nematode roundworm (Ascaris lumbricoides), the whipworm (Trichuris trichiura) and the two hookworms (Ancylostoma duodenale and Necator americanus), often collectively referred as geohelminths. Studies of geohelminthiasis in poorly nourished children in developing regions report that geohelminths contribute to stunted growth and cognitive impairment. Insights into immunology have shed light on the modulatory role of the parasite on the host immune system and have defined the role of T cells in controlling geohelminthic infection. Recent molecular biological techniques have created an opportunity to analyse the interaction between parasites and their hosts at the molecular level. This paper is a review of the recent literature that examined the prevalence of geohelminthiasis in developing countries, the association between geohelminths in relation to public health, parasitological/diagnostic features, and therapeutic and preventive aspects of these major soil-transmitted helminth (STH) pathogens in humans.

scholarly journals HMGA Genes and Proteins in Development and Evolution

2020 ◽  
Vol 21 (2) ◽  
pp. 654 ◽  
Author(s):  
Robert Vignali ◽  
Silvia Marracci
Keyword(s):  
Gene Expression ◽  
Cell Biology ◽  
Evolutionary Biology ◽  
High Mobility ◽  
High Mobility Group ◽  
Present Review ◽  
Regulatory Factors ◽  
Group A ◽  
Shed Light ◽  
Development And Evolution

HMGA (high mobility group A) (HMGA1 and HMGA2) are small non-histone proteins that can bind DNA and modify chromatin state, thus modulating the accessibility of regulatory factors to the DNA and contributing to the overall panorama of gene expression tuning. In general, they are abundantly expressed during embryogenesis, but are downregulated in the adult differentiated tissues. In the present review, we summarize some aspects of their role during development, also dealing with relevant studies that have shed light on their functioning in cell biology and with emerging possible involvement of HMGA1 and HMGA2 in evolutionary biology.

scholarly journals Independent host- and bacterium-based determinants protect a model symbiosis from phage predation

2021 ◽  
Author(s):  
Jonathan B Lynch ◽  
Brittany D Bennett ◽  
Bryan D Merrill ◽  
Edward G Ruby ◽  
Andrew J Hryckowian
Keyword(s):  
Extracellular Matrix ◽  
Microbial Communities ◽  
Marine Bacterium ◽  
Vibrio Fischeri ◽  
Euprymna Scolopes ◽  
Ambient Seawater ◽  
Bacterial Populations ◽  
Microbial Ecosystems ◽  
Shed Light

Bacteriophages (phages) are diverse and abundant constituents of microbial communities worldwide, and are capable of modulating bacterial populations in diverse ways. Here we describe a novel phage, ϕHNL01, which infects the marine bacterium Vibrio fischeri. We use culture-based approaches to demonstrate that mutations in the exopolysaccharide locus of V. fischeri render this bacterium resistant to infection by ϕHNL01, highlighting the extracellular matrix as a key determinant of phage tropism in this interaction. Additionally, using the natural symbiosis between V. fischeri and the squid Euprymna scolopes, we show that during colonization, V. fischeri is protected from phage present in the ambient seawater. Taken together, these findings shed light on independent yet synergistic host- and bacterium-based strategies for resisting symbiosis-disrupting phage predation, and present important implications for understanding these strategies in the context of host-associated microbial ecosystems.

Drastic changes in aquatic bacterial populations from the Cuatro Cienegas Basin (Mexico) in response to long-term environmental stress

2013 ◽  
Vol 104 (6) ◽  
pp. 1159-1175 ◽  
Author(s):  
Silvia Pajares ◽  
Luis E. Eguiarte ◽  
German Bonilla-Rosso ◽  
Valeria Souza
Keyword(s):  
Environmental Stress ◽  
Bacterial Populations ◽  
Cuatro Ciénegas ◽  
Cuatro Ciénegas Basin

scholarly journals SOCIAL JUSTICE, GENOMIC JUSTICE AND THE VEIL OF IGNORANCE: HARSANYI MEETS MENDEL

2012 ◽  
Vol 28 (1) ◽  
pp. 43-71 ◽  
Author(s):  
Samir Okasha
Keyword(s):  
John Rawls ◽  
Evolutionary Biology ◽  
Thought Experiment ◽  
Veil Of Ignorance ◽  
Mendelian Genetics ◽  
Division Process ◽  
Impartial Observer ◽  
The Veil ◽  
John Harsanyi ◽  
Shed Light

John Harsanyi and John Rawls both used the veil of ignorance thought experiment to study the problem of choosing between alternative social arrangements. With his ‘impartial observer theorem’, Harsanyi tried to show that the veil of ignorance argument leads inevitably to utilitarianism, an argument criticized by Sen, Weymark and others. A quite different use of the veil-of-ignorance concept is found in evolutionary biology. In the cell-division process called meiosis, in which sexually reproducing organisms produce gametes, the chromosome number is halved; when meiosis is fair, each gene has only a fifty percent chance of making it into any gamete. This creates a Mendelian veil of ignorance, which has the effect of aligning the interests of all the genes in an organism. This paper shows how Harsanyi's version of the veil-of-ignorance argument can shed light on Mendelian genetics. There turns out to be an intriguing biological analogue of the impartial observer theorem that is immune from the Sen/Weymark objections to Harsanyi's original.

Revisiting the ‘Darwin–Marx correspondence’: Multiple discovery and the rhetoric of priority

2021 ◽  
pp. 095269512110192
Author(s):  
Joel Barnes
Keyword(s):  
Social Sciences ◽  
Evolutionary Biology ◽  
Karl Marx ◽  
Charles Darwin ◽  
Natural Sciences ◽  
History Of Ideas ◽  
Research Infrastructures ◽  
History Of ◽  
The Relationship ◽  
Shed Light

Between the 1930s and the mid 1970s, it was commonly believed that in 1880 Karl Marx had proposed to dedicate to Charles Darwin a volume or translation of Capital but that Darwin had refused. The detail was often interpreted by scholars as having larger significance for the question of the relationship between Darwinian evolutionary biology and Marxist political economy. In 1973–4, two scholars working independently—Lewis Feuer, professor of sociology at Toronto, and Margaret Fay, a graduate student at Berkeley—determined simultaneously that the traditional story of the proposed dedication was untrue, being based on a long-standing misinterpretation of the relevant correspondence. Between the two, and among several other scholars who became their respective allies, there developed a contest of authority and priority over the discovery. From 1975 to 1982, the controversy generated a considerable volume of spilled ink in both scholarly and popular publications. Drawing on previously unexamined archival resources, this article revisits the ‘case’ of the so-called ‘Darwin–Marx correspondence’ as an instance of the phenomenon of ‘multiple discovery’. A familiar occurrence in the natural sciences, multiple discovery is rarer in the humanities and social sciences. The present case of a priority dispute in the history of ideas followed patterns familiar from such disputes in the natural sciences, while also diverging from them in ways that shed light on the significance of disciplinary norms and research infrastructures.

scholarly journals The evolution of multicellular complexity: the role of relatedness and environmental constraints

2019 ◽  
Author(s):  
RM Fisher ◽  
JZ Shik ◽  
JJ Boomsma
Keyword(s):  
Physical Environment ◽  
Evolutionary Biology ◽  
Social Evolution ◽  
Group Formation ◽  
Environmental Constraints ◽  
Evolutionary Transitions ◽  
Slime Moulds ◽  
The Many ◽  
Shed Light

AbstractA major challenge in evolutionary biology has been to explain the variation in multicellularity across the many independently evolved multicellular lineages, from slime moulds to humans. Social evolution theory has highlighted the key role of relatedness in determining multicellular complexity and obligateness, however there is a need to extend this to a broader perspective incorporating the role of the environment. In this paper, we formally test Bonner’s 1998 hypothesis that the environment is crucial in determining the course of multicellular evolution, with aggregative multicellularity evolving more frequently on land and clonal multicellularity more frequently in water. Using a combination of scaling theory and phylogenetic comparative analyses, we describe multicellular organisational complexity across 139 species spanning 14 independent transitions to multicellularity and investigate the role of the environment in determining multicellular group formation and in imposing constraints on multicellular evolution. Our results, showing that the physical environment has impacted the way in which multicellular groups form, could shed light on the role of the environment for other major evolutionary transitions.

scholarly journals Exceptional soft tissues preservation in a mummified frog-eating Eocene salamander

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3861 ◽  
Author(s):  
Jérémy Tissier ◽  
Jean-Claude Rage ◽  
Michel Laurin
Keyword(s):  
Digestive Tract ◽  
Evolutionary Biology ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Exceptional Case ◽  
Three Dimensions ◽  
Rare Type ◽  
Internal Structures ◽  
Close Source ◽  
Shed Light

Fossils are almost always represented by hard tissues but we present here the exceptional case of a three-dimensionally preserved specimen that was ‘mummified’ (likely between 40 and 34 million years ago) in a terrestrial karstic environment. This fossil is the incomplete body of a salamander, Phosphotriton sigei, whose skeleton and external morphology are well preserved, as revealed by phase-contrast synchrotron X-ray microtomography. In addition, internal structures composed of soft tissues preserved in three dimensions are now identified: a lung, the spinal cord, a lumbosacral plexus, the digestive tract, muscles and urogenital organs that may be cloacal glands. These are among the oldest known cases of three-dimensional preservation of these organs in vertebrates and shed light on the ecology of this salamander. Indeed, the digestive tract contains remains of a frog, which represents the only known case of an extinct salamander that fed on a frog, an extremely rare type of predation in extant salamanders. These new data improve our scarce knowledge on soft tissue anatomy of early urodeles and should prove useful for future biologists and palaeontologists working on urodele evolutionary biology. We also suggest that the presence of bat guano and carcasses represented a close source of phosphorus, favouring preservation of soft tissues. Bone microanatomy indicates that P. sigei was likely amphibious or terrestrial, and was probably not neotenic.

scholarly journals The Influence of Flower Anatomy and Apple Cultivar on the Apple Flower Phytobiome

2018 ◽  
Vol 2 (3) ◽  
pp. 171-179 ◽  
Author(s):  
Blaire Steven ◽  
Regan B. Huntley ◽  
Quan Zeng
Keyword(s):  
Community Structure ◽  
Relative Abundance ◽  
Management Strategies ◽  
Bacterial Populations ◽  
Operational Taxonomic Units ◽  
Sequence Identity ◽  
Apple Cultivars ◽  
High Dominance ◽  
Structure Correlation ◽  
Shed Light

The apple flower is a transient organ that can shed light on how plant-associated phytobiomes are established and structured. Stigmas, stamens, receptacles, and petals were dissected from flowers, and the microbiome of each structure was characterized. Each flower part harbored a largely overlapping set of bacterial taxa, predominantly within the groups Pseudomonas and Enterobacteriaceae. However, the structure of the communities differed. The stigmas showed a high dominance of a small number of operational taxonomic units (OTUs; 97% sequence identity) whereas OTUs on petals were more even in relative abundance. Results from the OTU analysis of phytobiomes from stigmas from three apple cultivars, Braeburn, McIntosh, and Sunrise, indicated cultivar did not significantly influence community structure. Correlation analysis of bacterial taxa in the apple phytobiome found a negative correlation between Pseudomonas and Enterobacteriaceae, suggesting a potential niche exclusion relationship between these taxa. In this respect, the phytobiome of the apple flower is relatively simple but different flower parts, particularly the stigma, enrich the relative abundance of specific bacterial populations. Correlations in the community structure point to potential antagonistic relationships, which could be used to manipulate the structure of the microbiome for biological control of pathogens or other orchard management strategies.

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