major transitions
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2022 ◽  
Author(s):  
Jean Keller ◽  
Camille Puginier ◽  
Cyril Libourel ◽  
Juergen Otte ◽  
Pavel Skaloud ◽  
...  

Mutualistic symbioses, such as lichens formed between fungi and green algae or cyanobacteria, have contributed to major transitions in the evolution of life and are at the center of extant ecosystems. However, our understanding of their evolution and function remains elusive in most cases. Here, we investigated the evolutionary history and the molecular innovations at the origin of lichens in green algae. We de novo sequenced the genomes or transcriptomes of 15 lichen-forming and closely-related non-lichen-forming algae and performed comparative phylogenomics with 22 genomes previously generated. We identified more than 350 functional categories significantly enriched in chlorophyte green algae able to form lichens. Among them, functions such as light perception or resistance to dehydration were shared between lichenizing and other terrestrial algae but lost in non-terrestrial ones, indicating that the ability to live in terrestrial habitats is a prerequisite for lichens to evolve. We detected lichen-specific expansions of glycosyl hydrolase gene families known to remodel cell walls, including the glycosyl hydrolase 8 which was acquired in lichenizing Trebouxiophyceae by horizontal gene transfer from bacteria, concomitantly with the ability to form lichens. Mining genome-wide orthogroups, we found additional evidence supporting at least two independent origins of lichen-forming ability in chlorophyte green algae. We conclude that the lichen-forming ability evolved multiple times in chlorophyte green algae, following a two-step mechanism which involves an ancestral adaptation to terrestrial lifestyle and molecular innovations to modify the partners cell walls.


2021 ◽  
Vol 13 (2021/1) ◽  
Author(s):  
Melinda Papp

Coming of age, as one of the major transitions in the human life cycle, marks the threshold between childhood and adulthood. This transition involves the physical and psychological, as well as the social maturity of the individual. The present article discusses the contemporary practice of the Japanese coming of age ritual, known as seijinshiki, which although it is a relatively modern invention, is nourished by a century-long tradition of coming of age rituals as well as by the traditional world-view on the human life cycle. Today, the ceremony is facing a new challenge due to the upcoming changes in the age of legal adulthood in Japan. Seijinshiki is an excellent example of how change is integrated as well as reflected throughout ritual practice. It vividly reflects social processes as well as mirroring several problems that Japanese society has been facing in our own time. The paper will examine some of these problems together with the major changes that affected the various forms of coming of age rites in Japan across history. The paper also demonstrates that ritual continues to be regarded in Japan as a valid social and individual instrument to treat passages in human life.


2021 ◽  
Vol 9 ◽  
Author(s):  
Amanda N. Robin ◽  
Kaleda K. Denton ◽  
Eva S. Horna Lowell ◽  
Tanner Dulay ◽  
Saba Ebrahimi ◽  
...  

A small number of extraordinary “Major Evolutionary Transitions” (METs) have attracted attention among biologists. They comprise novel forms of individuality and information, and are defined in relation to organismal complexity, irrespective of broader ecosystem-level effects. This divorce between evolutionary and ecological consequences qualifies unicellular eukaryotes, for example, as a MET although they alone failed to significantly alter ecosystems. Additionally, this definition excludes revolutionary innovations not fitting into either MET type (e.g., photosynthesis). We recombine evolution with ecology to explore how and why entire ecosystems were newly created or radically altered – as Major System Transitions (MSTs). In doing so, we highlight important morphological adaptations that spread through populations because of their immediate, direct-fitness advantages for individuals. These are Major Competitive Transitions, or MCTs. We argue that often multiple METs and MCTs must be present to produce MSTs. For example, sexually-reproducing, multicellular eukaryotes (METs) with anisogamy and exoskeletons (MCTs) significantly altered ecosystems during the Cambrian. Therefore, we introduce the concepts of Facilitating Evolutionary Transitions (FETs) and Catalysts as key events or agents that are insufficient themselves to set a MST into motion, but are essential parts of synergies that do. We further elucidate the role of information in MSTs as transitions across five levels: (I) Encoded; (II) Epigenomic; (III) Learned; (IV) Inscribed; and (V) Dark Information. The latter is ‘authored’ by abiotic entities rather than biological organisms. Level IV has arguably allowed humans to produce a MST, and V perhaps makes us a FET for a future transition that melds biotic and abiotic life into one entity. Understanding the interactive processes involved in past major transitions will illuminate both current events and the surprising possibilities that abiotically-created information may produce.


Religions ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1078
Author(s):  
Veronica Strang

There are diverse historical trajectories in human societies’ relationships with the non-human world. While many small place-based groups have tried to retain egalitarian partnerships with other species and ecosystems, larger societies have made major transitions. In religious terms, they have moved from worshipping female, male or androgynous non-human deities, to valorising pantheons of deities that, over time, became semi-human and then human in form. Reflecting Durkheimian changes in social and political arrangements, movements towards patriarchy led to declining importance in female deities, and the eventual primacy of single male Gods. With these changes came dualistic beliefs separating Culture from Nature, gendering these as male and female, and asserting male dominion over both Nature and women. These beliefs supported activities that have led to the current environmental crisis: unrestrained growth; hegemonic expansion; colonialism, and unsustainable exploitation of the non-human world. These are essentially issues of inequality: between genders, between human groups, and between human societies and other living kinds. This paper draws on a series of ethnographic research projects (since 1992) exploring human-environmental relationships, primarily in Australia, the UK, and New Zealand, and on a larger comparative study, over many years, of a range of ethnographic, archaeological, theological, and historical material from around the world. It considers contemporary debates challenging Nature-Culture dualism and promoting ‘rights for Nature’ or—rejecting anthropocentricity to recognize an indivisible world—for the non-human communities with whom we co-inhabit ecosystems. Proposing new ways to configure ethical debates, it suggests that non-human rights are, like women’s rights, fundamentally concerned with power relations, social status, and access to material resources, to the extent that the achievement of ‘pan-species democracy’ and greater equality between living kinds goes hand-in-hand with social, political and religious equality between genders.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 101-102
Author(s):  
Sarah Hahn ◽  
Jennifer Kinney

Abstract With the rapid aging of the population, the need for gerontological educators to identify pedagogical strategies to increase interest and prepare students continues to grow. Innovative approaches and educational practices contribute greatly to student success in the gerontological classroom. Literature on gerontological pedagogy has shed light on the success of high-impact practices, creative assignments, pedagogical interventions, and even different course modalities when it comes to effectively delivering gerontological content and engaging students. Additionally, the Academy for Gerontology in Higher Education (AGHE) provides a wealth of suggestions for creating and implementing effective gerontology courses and assignments. However, while we are familiar with these practices, we are not familiar with how specific groups of academics, such as emerging scholars and junior faculty, are utilizing them. Emerging scholars and junior faculty experience several major transitions as they prepare for life in academia. To ensure that emerging scholars and junior faculty are well prepared, we need to continue to empower these individuals to foster growth. This can be done by highlighting how emerging scholars and junior faculty have met the goals of maximizing and optimizing student learning. As such, the purpose of this symposium is to examine innovative approaches used by emerging scholars and junior academics in the gerontological classroom that have optimized student learning. This includes presentations on strategies for team-based learning, using intersectionality as a theoretical lens, and two creative written assignments, The Gerontological Movie Database Review and Interview an Elder.


2021 ◽  
Author(s):  
Vitaly Vanchurin ◽  
Yuri I. Wolf ◽  
Mikhail Katsnelson ◽  
Eugene V. Koonin

We apply the theory of learning to physically renormalizable systems in an attempt to develop a theory of biological evolution, including the origin of life, as multilevel learning. We formulate seven fundamental principles of evolution that appear to be necessary and sufficient to render a universe observable and show that they entail the major features of biological evolution, including replication and natural selection. These principles also follow naturally from the theory of learning. We formulate the theory of evolution using the mathematical framework of neural networks, which provides for detailed analysis of evolutionary phenomena. To demonstrate the potential of the proposed theoretical framework, we derive a generalized version of the Central Dogma of molecular biology by analyzing the flow of information during learning (back-propagation) and predicting (forward-propagation) the environment by evolving organisms. The more complex evolutionary phenomena, such as major transitions in evolution, in particular, the origin of life, have to be analyzed in the thermodynamic limit, which is described in detail in the accompanying paper.


Genes ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1532
Author(s):  
J. Mark Cock

The emergence of multicellular organisms was, perhaps, the most spectacular of the major transitions during the evolutionary history of life on this planet [...]


2021 ◽  
Author(s):  
Katie Mika ◽  
Camilla M. Whittington ◽  
Bronwyn M. McAllan ◽  
Vincent J Lynch

Structural and physiological changes in the female reproductive system underlie the origins of pregnancy in multiple vertebrate lineages. In mammals, for example, the glandular portion of the lower reproductive tract has transformed into a structure specialized for supporting fetal development. These specializations range from relatively simple maternal provisioning in egg-laying monotremes to an elaborate suite of traits that support intimate maternal-fetal interactions in Eutherians. Among these traits are the maternal decidua and fetal component of the placenta, but there is considerable uncertainty about how these structures evolved. We identified the origins of pregnancy utilizing ancestral transcriptome reconstruction to infer functional evolution of the maternal-fetal interface. Remarkably, we found that maternal gene expression profiles are correlated with degree of placental invasion. These results indicate that an epitheliochorial-like placenta evolved early in the mammalian stem-lineage and that the ancestor of Eutherians had a hemochorial placenta, and suggest maternal control of placental invasiveness. Collectively, these data resolve major transitions in the evolution of pregnancy and indicate that ancestral transcriptome reconstruction can be used to study the function of ancestral cell, tissue, and organ systems.


2021 ◽  
Author(s):  
Salva Duran-Nebreda ◽  
Sergi Valverde

The evolution of computing is an example of a major, transformative technological adaptation still unfolding in human history. Information technologies are supported by many other knowledge domains that have evolved through a cumulative cultural process, yet at the same time computing affects the tempo and mode of cultural evolution, greatly accelerating innovation processes driven by recombination of present technologies. Additionally, computing has created entire new domains for cumulative cultural evolution, furthering an era dominated by digital economies and media. These new domains offer very desirable qualities for cultural evolution research and digital archaeology, including good coverage in data completeness in widely different aspects of human culture, from social networks to innovation in programming languages. We review the major transitions in information technologies, with especial interest in their connections to a biological evolutionary framework. In particular, software vs. hardware evolution poses an interesting example of symbiotic technologies that display strong social dependencies as well as an extrinsic fitness due to energetic and temporal constrains. Properly accounting for the interplay of material and social factors can explain the coexistence of gradualism and punctuated dynamics in cultural and technological evolution.


2021 ◽  
Author(s):  
Hongmi Lee ◽  
Janice Chen

AbstractCurrent theory and empirical studies suggest that humans segment continuous experiences into events based on the mismatch between predicted and actual sensory inputs; detection of these “event boundaries” evokes transient neural responses. However, boundaries can also occur at transitions between internal mental states, without relevant external input changes. To what extent do such “internal boundaries” share neural response properties with externally-driven boundaries? We conducted an fMRI experiment where subjects watched a series of short movies and then verbally recalled the movies, unprompted, in the order of their choosing. During recall, transitions between movies thus constituted major boundaries between internal mental contexts, generated purely by subjects’ unguided thoughts. Following the offset of each recalled movie, we observed stereotyped spatial activation patterns in the default mode network, especially the posterior medial cortex, consistent across different movie contents and even across the different tasks of movie watching and recall. Surprisingly, the between-movie boundary patterns were negatively correlated with patterns at boundaries between events within a movie. Thus, major transitions between mental contexts elicit neural phenomena shared across internal and external modes and distinct from within-context event boundary detection, potentially reflecting a cognitive state related to the flushing and reconfiguration of situation models.


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