Evolutionary exobiology: towards the qualitative assessment of biological potential on exoplanets

2017 ◽  
Vol 18 (3) ◽  
pp. 204-208 ◽  
Author(s):  
David S. Stevenson ◽  
Sean Large
Keyword(s):  
Physical Properties ◽  
Evolutionary Theory ◽  
Liquid Water ◽  
Life Forms ◽  
Qualitative Assessment ◽  
Mathematical Framework ◽  
Biological Potential ◽  
Basic Set ◽  
Terrestrial Life ◽  
Definition Of

AbstractA planet may be defined as habitable if it has an atmosphere and is warm enough to support the existence of liquid water on its surface. Such a world has the basic set of conditions that allow it to develop life similar to ours, which is carbon-based and has water as its universal solvent. While this definition is suitably vague to allow a fairly broad range of possibilities, it does not address the question as to whether any life that does form will become either complex or intelligent. In this paper, we seek to synthesize a qualitative definition of which subset of these ‘habitable worlds’ might develop more complex and interesting life forms. We identify two key principles in determining the capacity of life to breach certain transitions on route to developing intelligence. The first is the number of potential niches a planet provides. Secondly, the complexity of life will reflect the information density of its environment, which in turn can be approximated by the number of available niches. We seek to use these criteria to begin the process of placing the evolution of terrestrial life in a mathematical framework based on environmental information content. This is currently testable on Earth and will have clear application to the worlds that we are only beginning to discover. Our model links the development of complex life to the physical properties of the planet, something which is currently lacking in all evolutionary theory.

scholarly journals The Principles of Life

2020 ◽  
Author(s):  
Diogo Gonçalves
Keyword(s):  
Metabolic Flux ◽  
Life Forms ◽  
Theoretical Framework ◽  
Living Systems ◽  
Complete Understanding ◽  
Chemical Systems ◽  
Terrestrial Life ◽  
Long Time ◽  
Definition Of ◽  
The Doors

The questions of what life is and how it first started have for a long-time daunted science. Our rather small understanding of what living systems are is demonstrated by the inexistence of a widely accepted chemical definition of them. This work intends to solve this long-lasting problem by laying such a definition as well as the principles that have governed living systems since their inception up to their extant forms. Here I show that living entities are productive chemical systems that bias their own formation. It will be shown that these two aspects inevitably lead to a selection by the highest replicative metabolic flux, explaining all the characteristics of extant living systems, where the strength of the biasing effect can be considered the main difference between life now, and at its origin. By building a narrative on how such a journey may have taken place, this work intends to provide the theoretical framework and experimental inspiration for a complete understanding of evolution, simultaneously creating new avenues to the search for extra-terrestrial life forms and opening the doors to the development of living technologies.

SYSTEMATIC DEFINITION OF COMPLEXITY ASSEMBLY IN FRACTAL POROUS MEDIA

Fractals ◽  
2020 ◽  
Vol 28 (05) ◽  
pp. 2050079 ◽  
Author(s):  
YI JIN ◽  
CHENG WANG ◽  
SHUNXI LIU ◽  
WEIZHE QUAN ◽  
XIAOKUN LIU
Keyword(s):  
Porous Media ◽  
Physical Properties ◽  
Mathematical Framework ◽  
Control Mechanisms ◽  
Scale Invariant ◽  
Structure Generation ◽  
Behavioral Complexity ◽  
Multi Scale ◽  
Definition Of ◽  
Multi Phase

Microstructures dominate the physical properties of fractal porous media, which means the clarification of complexity types and their assembly are of fundamental importance for static or dynamic purposes. In this work, we identified fractal porous media to dual-complexity systems composed of stationary and scale-invariant complexities as per fractal topography theory, and proposed an open mathematical framework to characterize complexity assembly in microstructures, realized the original complexity, such as random, multi-phase, and multi-type features by the quartet structure generation set (QSGS) algorithm, and unified the behavioral complexity, including the self-similar and self-affine properties by fractal topography model. For demonstration, the control mechanisms on the microstructures from different complexities are discussed, with their physical implications and relations to the physical properties of porous media clarified in principle. The results indicate that our framework is open to arbitrary original and behavioral complexities, and eases the modeling of multi-scale microstructures and the property estimation significantly.

Transmission electron microscopy of composite materials

1988 ◽  
Vol 46 ◽  
pp. 1012-1015
Author(s):  
K.P.D. Lagerlof
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Structural Defects ◽  
Structural Composites ◽  
Multiphase Materials ◽  
Structural Reinforcement ◽  
Transmission Electron ◽  
Reinforced Fiber ◽  
Particulate Reinforced Composites ◽  
Definition Of

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.

scholarly journals CONCEPTUAL DESIGN FOR ASSEMBLY IN AEROSPACE INDUSTRY: SENSITIVITY ANALYSIS OF MATHEMATICAL FRAMEWORK AND DESIGN PARAMETERS

2021 ◽  
Vol 1 ◽  
pp. 731-740
Author(s):  
Giovanni Formentini ◽  
Claudio Favi ◽  
Claude Cuiller ◽  
Pierre-Eric Dereux ◽  
Francois Bouissiere ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Conceptual Design ◽  
Design Parameters ◽  
Design For Assembly ◽  
Mathematical Framework ◽  
Commercial Aircraft ◽  
System Architectures ◽  
Complex Engineering ◽  
Aircraft System ◽  
Definition Of

AbstractOne of the most challenging activity in the engineering design process is the definition of a framework (model and parameters) for the characterization of specific processes such as installation and assembly. Aircraft system architectures are complex structures used to understand relation among elements (modules) inside an aircraft and its evaluation is one of the first activity since the conceptual design. The assessment of aircraft architectures, from the assembly perspective, requires parameter identification as well as the definition of the overall analysis framework (i.e., mathematical models, equations).The paper aims at the analysis of a mathematical framework (structure, equations and parameters) developed to assess the fit for assembly performances of aircraft system architectures by the mean of sensitivity analysis (One-Factor-At-Time method). The sensitivity analysis was performed on a complex engineering framework, i.e. the Conceptual Design for Assembly (CDfA) methodology, which is characterized by level, domains and attributes (parameters). A commercial aircraft cabin system was used as a case study to understand the use of different mathematical operators as well as the way to cluster attributes.

scholarly journals Novel water source for endolithic life in the hyperarid core of the Atacama Desert

2012 ◽  
Vol 9 (6) ◽  
pp. 2275-2286 ◽  
Author(s):  
J. Wierzchos ◽  
A. F. Davila ◽  
I. M. Sánchez-Almazo ◽  
M. Hajnos ◽  
R. Swieboda ◽  
...  
Keyword(s):  
Liquid Water ◽  
Capillary Condensation ◽  
Extreme Environments ◽  
Atacama Desert ◽  
Water Source ◽  
Life Forms ◽  
Alternative Source ◽  
Biological Adaptation ◽  
Salt Flats ◽  
Life On Earth

Abstract. The hyperarid core of the Atacama Desert, Chile, is possibly the driest and most life-limited place on Earth, yet endolithic microorganisms thrive inside halite pinnacles that are part of ancient salt flats. The existence of this microbial community in an environment that excludes any other life forms suggests biological adaptation to high salinity and desiccation stress, and indicates an alternative source of water for life other than rainfall, fog or dew. Here, we show that halite endoliths obtain liquid water through spontaneous capillary condensation at relative humidity (RH) much lower than the deliquescence RH of NaCl. We describe how this condensation could occur inside nano-pores smaller than 100 nm, in a newly characterized halite phase that is intimately associated with the endolithic aggregates. This nano-porous phase helps retain liquid water for long periods of time by preventing its evaporation even in conditions of utmost dryness. Our results explain how life has colonized and adapted to one of the most extreme environments on our planet, expanding the water activity envelope for life on Earth, and broadening the spectrum of possible habitats for life beyond our planet.

Looking for Patterns

2021 ◽  
pp. 57-73
Author(s):  
Talia Dan-Cohen
Keyword(s):  
Life Forms ◽  
Experimental Results ◽  
Close Attention ◽  
Vast Array ◽  
Observational Skills ◽  
Definition Of ◽  
By Products

This chapter focuses on ambiguous experimental results, paying close attention to experimental processes and tracking the ways that practitioners tackle, reason, and think through puzzling experimental results. It investigates the context of experiments with modified life-forms and experimental results that take the form of a vast array of biotic not-quites. It also highlights organismic by-products that point in various directions when it comes to figuring out how much control synthetic biologists have over their designs and what steps should be taken as correctives. The chapter explains how experiments often come packaged together with the choices, standards, and observational skills of others. It discusses the problem of the definition of growth that was deferred through the delineation of a category for the indeterminate results.

Petrophysical Rocks: Electrofacies and Lithofacies

2014 ◽  
Author(s):  
John H. Doveton
Keyword(s):  
Particle Size ◽  
Physical Properties ◽  
Sedimentary Rocks ◽  
Well Control ◽  
The Core ◽  
Lateral Extent ◽  
Petrophysical Logs ◽  
Definition Of

Many years ago, the classification of sedimentary rocks was largely descriptive and relied primarily on petrographic methods for composition and granulometry for particle size. The compositional aspect broadly matches the goals of the previous chapter in estimating mineral content from petrophysical logs. With the development of sedimentology, sedimentary rocks were now considered in terms of the depositional environment in which they originated. Uniformitarianism, the doctrine that the present is the key to the past, linked the formation of sediments in the modern day to their ancient lithified equivalents. Classification was now structured in terms of genesis and formalized in the concept of “facies.” A widely quoted definition of facies was given by Reading (1978) who stated, “A facies should ideally be a distinctive rock that forms under certain conditions of sedimentation reflecting a particular process or environment.” This concept identifies facies as process products which, when lithified in the subsurface, form genetic units that can be correlated with well control to establish the geological architecture of a field. The matching of facies with modern depositional analogs means that dimensional measures, such as shape and lateral extent, can be used to condition reasonable geomodels, particularly when well control is sparse or nonuniform. Most wells are logged rather than cored, so that the identification of facies in cores usually provides only a modicum of information to characterize the architecture of an entire field. Consequently, many studies have been made to predict lithofacies from log measurements in order to augment core observations in the development of a satisfactory geomodel that describes the structure of genetic layers across a field. The term “electrofacies” was introduced by Serra and Abbott (1980) as a way to characterize collective associations of log responses that are linked with geological attributes. They defined electrofacies to be “the set of log responses which characterizes a bed and permits it to be distinguished from the others.” Electrofacies are clearly determined by geology, because physical properties of rocks. The intent of electrofacies identification is generally to match them with lithofacies identified in the core or an outcrop.

An Overview of Positioning and Data Fusion Techniques Applied to Land Vehicle Navigation Systems

2010 ◽  
pp. 219-246 ◽  
Author(s):  
Denis Gingras
Keyword(s):  
Data Fusion ◽  
Mathematical Framework ◽  
Positioning System ◽  
Navigation Systems ◽  
Positioning Systems ◽  
Future Evolution ◽  
Land Vehicle Navigation ◽  
One Step ◽  
Definition Of ◽  
Position Estimate

In this chapter, the authors will review the problem of estimating in real-time the position of a vehicle for use in land navigation systems. After describing the application context and giving a definition of the problem, they will look at the mathematical framework and technologies involved to design positioning systems. The authors will compare the performance of some of the most popular data fusion approaches and provide some insights on their limitations and capabilities. They will then look at the case of robustness of the positioning system when one or some of the sensors are faulty and will describe how the positioning system can be made more robust and adaptive in order to take into account the occurrence of faulty or degraded sensors. Finally, they will go one step further and explore possible architectures for collaborative positioning systems, whereas many vehicles are interacting and exchanging data to improve their own position estimate. The chapter is concluded with some remarks on the future evolution of the field.

scholarly journals A Theory of Adaptive Intelligence and Its Relation to General Intelligence

2019 ◽  
Vol 7 (4) ◽  
pp. 23 ◽  
Author(s):  
Robert J. Sternberg
Keyword(s):  
Evolutionary Theory ◽  
Hierarchical Model ◽  
Cultural Context ◽  
General Factor ◽  
General Intelligence ◽  
Similarities And Differences ◽  
Definition Of ◽  
And Behavior

Intelligence typically is defined as consisting of “adaptation to the environment” or in related terms. Yet, it is not clear that “general intelligence” or g, traditionally conceptualized in terms of a general factor in a psychometrically-based hierarchical model of intelligence, provides an optimal way of defining intelligence as adaptation to the environment. Such a definition of adaptive intelligence would need to be biologically based in terms of evolutionary theory, would need to take into account the cultural context of adaptation, and would need to take into account whether thought and behavior labeled as “adaptively intelligent” actually contributed to the perpetuation of the human and other species, or whether it was indifferent or actually destructive to this perpetuation. In this article, I consider the similarities and differences between “general intelligence” and “adaptive intelligence,” as well as the implications especially of the differences.

scholarly journals Multiple evolutionary origins of giant viruses

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1840 ◽  
Author(s):  
Eugene V. Koonin ◽  
Natalya Yutin
Keyword(s):  
Life Forms ◽  
Translation System ◽  
Dna Viruses ◽  
Evolutionary Forces ◽  
Evolutionary Origins ◽  
Cellular Life ◽  
Giant Viruses ◽  
Nucleocytoplasmic Large Dna Viruses ◽  
Phylogenomic Analyses ◽  
Definition Of

The nucleocytoplasmic large DNA viruses (NCLDVs) are a monophyletic group of diverse eukaryotic viruses that reproduce primarily in the cytoplasm of the infected cells and include the largest viruses currently known: the giant mimiviruses, pandoraviruses, and pithoviruses. With virions measuring up to 1.5 μm and genomes of up to 2.5 Mb, the giant viruses break the now-outdated definition of a virus and extend deep into the genome size range typical of bacteria and archaea. Additionally, giant viruses encode multiple proteins that are universal among cellular life forms, particularly components of the translation system, the signature cellular molecular machinery. These findings triggered hypotheses on the origin of giant viruses from cells, likely of an extinct fourth domain of cellular life, via reductive evolution. However, phylogenomic analyses reveal a different picture, namely multiple origins of giant viruses from smaller NCLDVs via acquisition of multiple genes from the eukaryotic hosts and bacteria, along with gene duplication. Thus, with regard to their origin, the giant viruses do not appear to qualitatively differ from the rest of the virosphere. However, the evolutionary forces that led to the emergence of virus gigantism remain enigmatic.

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