scholarly journals Dynamic structures in evo-devo: From morphogenetic fields to evolving organisms

2021 ◽  
Author(s):  
Johannes Jaeger
Keyword(s):  
Active Role ◽  
Life Cycles ◽  
Evolutionary Change ◽  
Phenotypic Change ◽  
Agent Based ◽  
Theory Of Evolution ◽  
Dynamic Structures ◽  
Evo Devo ◽  
Morphogenetic Fields

Evolution does not act on particular stages in the life of an organism. Instead, it alters developmental processes and life cycles in response to environmental conditions to bring about phenotypic change. The structure of these processes determines evolvability, the capacity of organisms to adapt. These structures are intrinsically dynamic. The organisational principles underlying organisms and the morphogenetic fields that constitute their ontogeny actively remodel themselves over time. How this occurs, and how it influences the rate and direction of evolutionary change, are central questions for biology. They lead us to fundamentally reconsider the active role of organisms in evolutionary change, which raises the possibility of a new agent-based theory of evolution in which organisms and their perceived environments co-construct each other in a radically innovative dialectic dynamic.

The problem of variation

2021 ◽  
pp. 111-134
Author(s):  
Arlin Stoltzfus
Keyword(s):  
Quantitative Genetics ◽  
Raw Materials ◽  
Substantive Theory ◽  
Theory Of Evolution ◽  
Multivariate Generalization ◽  
Theory Of Variation ◽  
Broad Framework ◽  
The Moment ◽  
Evo Devo

Chapter 7 maps out a broad framework for considering the problem of variation in evolution. Under the neo-Darwinian view that variation merely plays the role of supplying random infinitesimal raw materials, with no dispositional influence on the course of evolution, a substantive theory of form and its variation is not required to specify a complete theory of evolution. This view has been breaking down from the moment it was proposed, and is now seriously challenged by results from evo-devo, comparative genomics, molecular evolution, and quantitative genetics. For instance, the multivariate generalization of quantitative genetics indicates that selection cannot possibly act as an independent governing force. Replacing a theory of variation as fuel with a theory of variation as a dispositional factor will require, at minimum, an understanding of tendencies of variation (source laws), and an understanding of how those tendencies affect evolution (consequence laws).

Evo-devo: A New Evolutionary Paradigm?

2005 ◽  
Vol 56 ◽  
pp. 105-124
Author(s):  
Michael Ruse
Keyword(s):  
Population Genetics ◽  
Natural Selection ◽  
Newtonian Mechanics ◽  
Evo Devo ◽  
Morphogenetic Fields ◽  
Better Than

The homologies of process within morphogenetic fields provide some of the best evidence for evolution—just as skeletal and organ homologies did earlier. Thus, the evidence for evolution is better than ever. The role of natural selection in evolution, however, is seen to play less an important role. It is merely a filter for unsuccessful morphologies generated by development. Population genetics is destined to change if it is not to become as irrelevant to evolution as Newtonian mechanics is to contemporary physics. (Gilbert, Opitz, and Raff 1996, 368)

Evo-devo: A New Evolutionary Paradigm?

2005 ◽  
Vol 56 ◽  
pp. 8-9
Author(s):  
Michael Ruse
Keyword(s):  
Population Genetics ◽  
Natural Selection ◽  
Newtonian Mechanics ◽  
Evo Devo ◽  
Morphogenetic Fields ◽  
Better Than

The homologies of process within morphogenetic fields provide some of the best evidence for evolution—just as skeletal and organ homologies did earlier. Thus, the evidence for evolution is better than ever. The role of natural selection in evolution, how–ever, is seen to play less an important role. It is merely a filter for unsuccessful morphologies generated by development. Population genetics is destined to change if it is not to become as irrelevant to evolution as Newtonian mechanics is to contempo–rary physics. (Gilbert, Opitz, and Raff 1996, 368)

scholarly journals Hidden paths to endless forms most wonderful: Ecology latently shapes evolution of multicellular development in predatory bacteria

2021 ◽  
Author(s):  
Marco La Fortezza ◽  
Olaya Rendueles ◽  
Heike Keller ◽  
Gregory Jon Velicer
Keyword(s):  
Soft Agar ◽  
Life Cycles ◽  
Multicellular Development ◽  
Surface Stiffness ◽  
Predatory Bacteria ◽  
Evolution Experiment ◽  
Developmental Phases ◽  
Open Question ◽  
Evo Devo

Ecological causes of developmental-system evolution, for example from predation, remain under intense investigation. An important open question is the role of latent phenotypes in eco-evo-devo. The predatory bacterium Myxococcus xanthus undergoes aggregative multicellular development upon starvation. Here we use M. xanthus to test whether evolution in several distinct growth environments that do not induce development latently alters developmental phenotypes, including morphology and plasticity, in environments that do induce development. In the MyxoEE-3 evolution experiment, growing M. xanthus populations swarmed across agar surfaces while adapting to distinct conditions varying at factors such as surface stiffness or prey identity. All examined developmental phenotypes underwent extensive and ecologically specific latent evolution, with surface stiffness, prey presence and prey identity all strongly impacting the latent evolution of development. Evolution on hard agar allowed retention of developmental proficiency and extensive stochastic phenotypic radiation, including of reaction norms, with instances of both increased plasticity and canalization. In contrast, evolution on soft agar latently led to systematic loss of development, revealing an ecologically-contingent fitness trade-off between the growth and developmental phases of a multicellular life cycle that is likely determined by details of motility behavior. Similar contingency was observed after evolution during predatory growth in distinct prey environments, with Bacillus subtilis causing greater loss of development and lower stochastic diversification than Escherichia coli. Our results have implications for understanding evolutionary interactions among predation, development and motility in myxobacterial life cycles, and, more broadly, the importance of latent phenotypes for the diversification of developmental systems.

Role of spectrin in membrane fusion and in shape change of human erythrocyte ghost

1978 ◽  
Vol 36 (2) ◽  
pp. 328-329
Author(s):  
Hideo Hayashi ◽  
Yoshikazu Hirai ◽  
John T. Penniston
Keyword(s):  
Conformational Changes ◽  
Human Erythrocyte ◽  
Shape Change ◽  
Membrane Surface ◽  
Slight Modification ◽  
Active Role ◽  
Main Role ◽  
Bank Blood ◽  
Human Erythrocyte Ghost

Spectrin is a membrane associated protein most of which properties have been tentatively elucidated. A main role of the protein has been assumed to give a supporting structure to inside of the membrane. As reported previously, however, the isolated spectrin molecule underwent self assemble to form such as fibrous, meshwork, dispersed or aggregated arrangements depending upon the buffer suspended and was suggested to play an active role in the membrane conformational changes. In this study, the role of spectrin and actin was examined in terms of the molecular arrangements on the erythrocyte membrane surface with correlation to the functional states of the ghosts.Human erythrocyte ghosts were prepared from either freshly drawn or stocked bank blood by the method of Dodge et al with a slight modification as described before. Anti-spectrin antibody was raised against rabbit by injection of purified spectrin and partially purified.

Elucidation of block boundaries as the dissolution channels in hydrated cement

1978 ◽  
Vol 36 (1) ◽  
pp. 484-485
Author(s):  
N.V. Belov ◽  
U.I. Papiashwili ◽  
B.E. Yudovich
Keyword(s):  
Liquid Phase ◽  
Grain Boundaries ◽  
Benzoyl Peroxide ◽  
Phase Contrast ◽  
Active Role ◽  
Point Of View ◽  
Hardened Cement ◽  
Hydrated Cement ◽  
Hardened Cement Paste

It has been almost universally adopted that dissolution of solids proceeds with development of uniform, continuous frontiers of reaction.However this point of view is doubtful / 1 /. E.g. we have proved the active role of the block (grain) boundaries in the main phases of cement, these boundaries being the areas of hydrate phases' nucleation / 2 /. It has brought to the supposition that the dissolution frontier of cement particles in water is discrete. It seems also probable that the dissolution proceeds through the channels, which serve both for the liquid phase movement and for the drainage of the incongruant solution products. These channels can be appeared along the block boundaries.In order to demonsrate it, we have offered the method of phase-contrast impregnation of the hardened cement paste with the solution of methyl metacrylahe and benzoyl peroxide. The viscosity of this solution is equal to that of water.

Potential Uses of Vinegar as a Medicine and Related in vivo Mechanisms

2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Review Paper ◽  
Heart Diseases ◽  
Folk Medicine ◽  
Active Role ◽  
Current Review ◽  
Different Types ◽  
Positive Effect

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.

Russia’s Market of Mergers and Acquisitions: Stages, Features and Prospects

2009 ◽  
pp. 23-45 ◽  
Author(s):  
A. Radygin
Keyword(s):  
Open Access ◽  
Mergers And Acquisitions ◽  
Corporate Control ◽  
Active Role ◽  
Data Bases ◽  
2008 Financial Crisis ◽  
Legal Norms ◽  
Role Of The State ◽  
Access Data

The article deals with key tendencies in the development of Russia’s market of mergers and acquisitions in the first decade of the 21st century. Quantitative parameters are analyzed by using available in the open access data bases for the years 2003-2008 taking into consideration new tendencies relating to 2008 financial crisis. An active role of the state played in the market of corporate control represents an important factor. Special attention is given to issues of development of Russia’s system of legal norms regulating the market of mergers and acquisitions.

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