Stromatolites: why do we care?

Ignaccolo, Massimiliano; Schwettmann, Arne; Failla, Roberto; Storrie-Lombardi, Michael C.; Grigolini, Paolo

doi:10.1016/s0960-0779(03)00437-5

Cited by 3 publications

(2 citation statements)

References 5 publications

(25 reference statements)

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“…As we have earlier mentioned the Kolmogorov complexity is not computable, and these techniques, directly or indirectly related to the concept of a Kolmogorov complexity, yield a computable measure measure of complexity. It is interesting to remark that, although these techniques are accurate, distinguishing with their help biotic from a-biotic systems remains a challenging issue [79,80] . It is interesting to notice that the field of complexity is reversing the current perspective.…”

Section: Conclusion: Objective Randomness Inducing a New Vision mentioning

confidence: 99%

From knowledge, knowability and the search for objective randomness to a new vision of complexity

Allegrini

Giuntoli

Grigolini

et al. 2004

Chaos, Solitons & Fractals

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Herein we consider various concepts of entropy as measures of the complexity of phenomena and in so doing encounter a fundamental problem in physics that affects how we understand the nature of reality. In essence the difficulty has to do with our understanding of randomness, irreversibility and unpredictability using physical theory, and these in turn undermine our certainty regarding what we can and what we cannot know about complex phenomena in general. The sources of complexity examined herein appear to be channels for the amplification of naturally occurring randomness in the physical world. Our analysis suggests that when the conditions for the renormalization group apply, this spontaneous randomness, which is not a reflection of our limited knowledge, but a genuine property of nature, does not realize the conventional thermodynamic state, and a new condition, intermediate between the dynamic and the thermodynamic state, emerges. We argue that with this vision of complexity, life, which with ordinary statistical mechanics seems to be foreign to physics, becomes a natural consequence of dynamical processes. I. INTRODUCTIONWhy do things get more complicated with the passage of time? While it may not be a mathematical theorem, it certainly seems clear that as cultures, technologies, biological species and indeed most large-scale systems, those with many interacting components, evolve over time either they become more complex or they die out. The goal of understanding the mechanisms by which evolution favors increased complexity over time is too ambitious an undertaking for us here. We do not explore these mechanisms in part because they are phenomena-specific and we are concerned with only the universal properties of complexity even though it has no clear definition. More importantly, however, complexity is very often self-generating. Herein we discuss many of the problems and paradoxes that are entangled in the concept of complexity in the restricted domain of the physical sciences. This is done because if complexity does have universal properties they should be independent of the phenomena being studied and therefore we choose the simplest context possible. For example the generation and dissipation of fluctuations involved in complex phenomena are examined through the concepts of irreversibility and randomness, but more importantly through the objectivity principle, see for example Monod [1]. The science of complexity is multidisciplinary and so it might by argued that the schema we construct, based on the paradigm of physics, is incomplete. On the other hand, we believe that the principle of objectiveness gives "hard" sciences like physics an important advantage in addressing the difficult task of understanding complex systems. As a matter of fact, we should not ignore centuries of philosophy of science and, more generally speaking, epistemology, when we refer to the concept of objectiveness. It is right in this case indeed that science and philosophy benefit by mutual exchanges. We can accept the fact tha...

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Section: Conclusion: Objective Randomness Inducing a New Vision mentioning

confidence: 99%

From knowledge, knowability and the search for objective randomness to a new vision of complexity

Allegrini

Giuntoli

Grigolini

et al. 2004

Chaos, Solitons & Fractals

Self Cite

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“…Nestas lagoas podem ser observadas estruturas estromatolíticas (Ignaccolo et al, 2004). Conhecidas desde o Arqueano até o Holoceno , tais estruturas foram abundantes até o Neoproterozoico, porém no final do Proterozoico ocorreu grande declínio, tanto na diversidade quanto na abundância (Riding, 1991).…”

Section: Introductionunclassified

Composição cianobacteriana e química dos estromatólitos da lagoa Salgada, Neógeno do estado do Rio de Janeiro, Brasil

Silva

Alves

Magina

et al. 2013

Geol. USP, Sér. cient.

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Disponível on-line no endereço www.igc.usp.br/geologiausp -95 -Resumo A lagoa Salgada é um corpo aquático costeiro, situada no norte do estado do Rio de Janeiro. A evolução geológica da lagoa está associada às oscilações do nível do mar durante o Neógeno e apresenta esteiras microbianas, estromatólitos estratiformes e estromatólitos individuais e contínuos. Estromatólitos são estruturas carbonáticas laminadas formadas pela atividade metabólica de esteiras microbianas. O estudo permitiu a identificação de 31 espécies de cianobactérias nos estromatólitos e nas esteiras microbianas. A família de maior frequência é a Synechococcaceae. Nove espécies ocorrem nos estágios de desenvolvimento dos estromatólitos. Os tipos de esteiras são lisa, tufada, poligonal e em bolha, tendo como seus principais agentes produtores as cianobactérias filamentosas. Os restos esqueletais incluem bivalves, gastrópodes, ostracódios, foraminíferos e outros táxons. A alta frequência de cianobactérias ocorre pela adaptação à salinidade aliada à baixa competição na área. Os resultados possibilitam inferir os paleoambientes e eventos de sedimentação ocorridos na lagoa e podem ser aplicados na interpretação dos estromatólitos pretéritos.Palavras-chave: Cianobactérias; Esteiras microbianas; Estromatólitos recentes; Lagoa Salgada; Brasil. AbstractSalgada lagoon is a coastal aquatic body in northern Rio de Janeiro state. The geological evolution of the lagoon is associated with the oscillation of sea level during the Late Neogene. The lagoon presents microbial mats, stratiform stromatolites, individual and continuous stromatolites. Stromatolites are laminated carbonate build-ups formed by the metabolic activity of microbial mats. This study identified 31 species of cyanobacteria in stromatolites and microbial mats. The Family Synechococcaceae is the most frequent. Nine species are usual throughout the evolution of the calcareous stromatolites. Microbial mat types include flat, tufted, polygonal and blister forms, all produced mainly by filamentous cyanobacteria. Skeletal remains include bivalves, gastropods, ostracods, foraminifers and other taxons. The high frequency of cyanobacteria in the area occurs because of their adaptation to hypersalinity allied to low competition. The results indicate that a variety of paleoenvironmental and sedimentary events occurred in the lagoon and may be applied to the interpretation of ancient stromatolites.

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Stromatolitic biotic systems in the mid-Triassic of Israel — A product of stress on an epicontinental margin

Meilijson

Bialik

Benjamini

2015

Palaeogeography, Palaeoclimatology, Palaeoecology

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Stromatolites: why do we care?

Cited by 3 publications

References 5 publications

From knowledge, knowability and the search for objective randomness to a new vision of complexity

From knowledge, knowability and the search for objective randomness to a new vision of complexity

Composição cianobacteriana e química dos estromatólitos da lagoa Salgada, Neógeno do estado do Rio de Janeiro, Brasil

Stromatolitic biotic systems in the mid-Triassic of Israel — A product of stress on an epicontinental margin

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