scholarly journals Noise-driven cell differentiation and the emergence of spatiotemporal patterns

2017 ◽  
Author(s):  
Hadiseh Safdari ◽  
Ata Kalirad ◽  
Cristian Picioreanu ◽  
Rouzbeh Tusserkani ◽  
Bahram Goliaei ◽  
...  
Keyword(s):  
Cell Aggregation ◽  
Self Organization ◽  
Major Transitions ◽  
Evolutionary Origins ◽  
Mechanistic Approach ◽  
Major Transition ◽  
Brave New World ◽  
Multicellular Organisms ◽  
Major Transitions In Evolution ◽  
Biological Innovations

AbstractOne of the major transitions in evolution is the step from unicellularity into the brave new world of multicellularity. To understand this feat, one has to fathom two main characteristics of multicellular organisms: differentiation and self-organization. Any explanation concerning this major transition should involve mechanisms that can simultaneously explain the marvellous intricacies manifest in the aforementioned characteristics, and an account of the evolution of such traits. Here we propose a noise-driven differentiation (NDD) model. The reliance on noise, in place of a more mechanistic approach, makes the NDD model a more suitable approach to explain differentiation and self-organization. Furthermore, our model sheds some light on the possible evolutionary origins of these biological innovations. To test the NDD model, we utilize a model of cell aggregation. The behavior of this model of cell aggregation is in concert with the NDD model.

The Major Transitions in Evolution

1997 ◽  
Author(s):  
John Maynard Smith ◽  
Eors Szathmary
Keyword(s):  
Full Range ◽  
Evolution Of Cooperation ◽  
Major Transitions ◽  
Insect Societies ◽  
Wide Range ◽  
Major Transition ◽  
Life Itself ◽  
History Of ◽  
Emergence Of Cooperation ◽  
Multicellular Organisms

Over the history of life there have been several major changes in the way genetic information is organized and transmitted from one generation to the next. These transitions include the origin of life itself, the first eukaryotic cells, reproduction by sexual means, the appearance of multicellular plants and animals, the emergence of cooperation and of animal societies, and the unique language ability of humans. This ambitious book provides the first unified discussion of the full range of these transitions. The authors highlight the similarities between different transitions--between the union of replicating molecules to form chromosomes and of cells to form multicellular organisms, for example--and show how understanding one transition sheds light on others. They trace a common theme throughout the history of evolution: after a major transition some entities lose the ability to replicate independently, becoming able to reproduce only as part of a larger whole. The authors investigate this pattern and why selection between entities at a lower level does not disrupt selection at more complex levels. Their explanation encompasses a compelling theory of the evolution of cooperation at all levels of complexity. Engagingly written and filled with numerous illustrations, this book can be read with enjoyment by anyone with an undergraduate training in biology. It is ideal for advanced discussion groups on evolution and includes accessible discussions of a wide range of topics, from molecular biology and linguistics to insect societies.

scholarly journals Mosaic evolution and the pattern of transitions in the hominin lineage

2016 ◽  
Vol 371 (1698) ◽  
pp. 20150244 ◽  
Author(s):  
Robert A. Foley
Keyword(s):  
Human Evolution ◽  
Eukaryotic Cell ◽  
Major Transitions ◽  
Major Transition ◽  
Novel Taxa ◽  
The Rich ◽  
Four Levels ◽  
Living Organisms ◽  
The Impact ◽  
Major Transitions In Evolution

Humans are uniquely unique, in terms of the extreme differences between them and other living organisms, and the impact they are having on the biosphere. The evolution of humans can be seen, as has been proposed, as one of the major transitions in evolution, on a par with the origins of multicellular organisms or the eukaryotic cell (Maynard Smith & Szathmáry 1997 Major transitions in evolution ). Major transitions require the evolution of greater complexity and the emergence of new evolutionary levels or processes. Does human evolution meet these conditions? I explore the diversity of evidence on the nature of transitions in human evolution. Four levels of transition are proposed—baseline, novel taxa, novel adaptive zones and major transitions—and the pattern of human evolution considered in the light of these. The primary conclusions are that changes in human evolution occur continuously and cumulatively; that novel taxa and the appearance of new adaptations are not clustered very tightly in particular periods, although there are three broad transitional phases (Pliocene, Plio-Pleistocene and later Quaternary). Each phase is distinctive, with the first based on ranging and energetics, the second on technology and niche expansion, and the third on cognition and cultural processes. I discuss whether this constitutes a ‘major transition’ in the context of the evolutionary processes more broadly; the role of behaviour in evolution; and the opportunity provided by the rich genetic, phenotypic (fossil morphology) and behavioural (archaeological) record to examine in detail major transitions and the microevolutionary patterns underlying macroevolutionary change. It is suggested that the evolution of the hominin lineage is consistent with a mosaic pattern of change. This article is part of the themed issue ‘Major transitions in human evolution’.

scholarly journals Spontaneous emergence of multicellular heritability

2021 ◽  
Author(s):  
Seyed Alireza Zamani-Dahaj ◽  
Anthony Burnetti ◽  
Thomas Day ◽  
william C Ratcliff ◽  
Peter J. Yunker ◽  
...  
Keyword(s):  
Genetic Regulation ◽  
Darwinian Evolution ◽  
Analytical Models ◽  
Biological Individuality ◽  
Cell Level ◽  
Evolutionary Transitions ◽  
Major Transitions ◽  
Additional Layer ◽  
Multicellular Organisms ◽  
Major Transitions In Evolution

The Major Transitions in evolution include events and processes that result in the emergence of new levels of biological individuality. For collectives to undergo Darwinian evolution, their traits must be heritable, but the emergence of higher-level heritability is poorly understood and has long been considered a stumbling block for nascent evolutionary transitions. A change in the means by which genetic information is utilized and transmitted has been presumed necessary. Using analytical models, synthetic biology, and biologically-informed simulations, we explored the emergence of trait heritability during the evolution of multicellularity. Contrary to existing theory, we show that no additional layer of genetic regulation is necessary for traits of nascent multicellular organisms to become heritable; rather, heritability and the capacity to respond to natural selection on multicellular-level traits can arise ''for free.'' In fact, we find that a key emergent multicellular trait, organism size at reproduction, is usually more heritable than the underlying cell-level trait upon which it is based, given reasonable assumptions.

scholarly journals Evolution of simple multicellularity increases environmental complexity

2016 ◽  
Author(s):  
María Rebolleda-Gómez ◽  
William C. Ratcliff ◽  
Jonathon Fankhauser ◽  
Michael Travisano
Keyword(s):  
Fluid Dynamics ◽  
Saccharomyces Cerevisiae ◽  
Experimental Evolution ◽  
Single Cells ◽  
Environmental Complexity ◽  
Major Transitions ◽  
Rapid Diversification ◽  
Ecological Mechanisms ◽  
Major Transitions In Evolution ◽  
Maintenance Of Diversity

AbstractMulticellularity—the integration of previously autonomous cells into a new, more complex organism—is one of the major transitions in evolution. Multicellularity changed evolutionary possibilities and facilitated the evolution of increased complexity. Transitions to multicellularity are associated with rapid diversification and increased ecological opportunity but the potential mechanisms are not well understood. In this paper we explore the ecological mechanisms of multicellular diversification during experimental evolution of the brewer’s yeast, Saccharomyces cerevisiae. The evolution from single cells into multicellular clusters modifies the structure of the environment, changing the fluid dynamics and creating novel ecological opportunities. This study demonstrates that even in simple conditions, incipient multicellularity readily changes the environment, facilitating the origin and maintenance of diversity.

4. Levels of selection

2019 ◽  
pp. 45-62
Author(s):  
Samir Okasha
Keyword(s):  
Kin Selection ◽  
Group Selection ◽  
Evolutionary Biology ◽  
Levels Of Selection ◽  
Major Transitions ◽  
Individual Level ◽  
Or Groups ◽  
The Subject ◽  
The Individual ◽  
Major Transitions In Evolution

‘Levels of selection’ examines the levels-of-selection question, which asks whether natural selection acts on individuals, genes, or groups. This question is one of the most fundamental in evolutionary biology, and the subject of much controversy. Traditionally, biologists have mostly been concerned with selection and adaptation at the individual level. But, in theory, there are other possibilities, including selection on sub-individual units such as genes and cells, and on supra-individual units such as groups and colonies. Group selection, altruistic behaviour, kin selection, the gene-centric view of evolution, and the major transitions in evolution are all discussed.

scholarly journals Cooperation and spatial self-organization determine rate and efficiency of particulate organic matter degradation in marine bacteria

2019 ◽  
Vol 116 (46) ◽  
pp. 23309-23316 ◽  
Author(s):  
Ali Ebrahimi ◽  
Julia Schwartzman ◽  
Otto X. Cordero
Keyword(s):  
Organic Matter ◽  
Public Goods ◽  
Social Interactions ◽  
Particulate Organic Matter ◽  
High Efficiency ◽  
Cell Aggregation ◽  
Self Organization ◽  
Turnover Rates ◽  
Particulate Carbon ◽  
Hydrolysis Of

The recycling of particulate organic matter (POM) by microbes is a key part of the global carbon cycle. This process is mediated by the extracellular hydrolysis of polysaccharides, which can trigger social behaviors in bacteria resulting from the production of public goods. Despite the potential importance of public good-mediated interactions, their relevance in the environment remains unclear. In this study, we developed a computational and experimental model system to address this challenge and studied how the POM depolymerization rate and its uptake efficiency (2 main ecosystem function parameters) depended on social interactions and spatial self-organization on particle surfaces. We found an emergent trade-off between rate and efficiency resulting from the competition between oligosaccharide diffusion and cellular uptake, with low rate and high efficiency being achieved through cell-to-cell cooperation between degraders. Bacteria cooperated by aggregating in cell clusters of ∼10 to 20 µm, in which cells were able to share public goods. This phenomenon, which was independent of any explicit group-level regulation, led to the emergence of critical cell concentrations below which degradation did not occur, despite all resources being available in excess. In contrast, when particles were labile and turnover rates were high, aggregation promoted competition and decreased the efficiency of carbon use. Our study shows how social interactions and cell aggregation determine the rate and efficiency of particulate carbon turnover in environmentally relevant scenarios.

scholarly journals Cancer and intercellular cooperation

2017 ◽  
Vol 4 (10) ◽  
pp. 170470 ◽  
Author(s):  
Marta Bertolaso ◽  
Anna Maria Dieli
Keyword(s):  
Natural Selection ◽  
Evolutionary Biology ◽  
Darwinian Evolution ◽  
Individual Organism ◽  
Major Transitions ◽  
Somatic Evolution ◽  
Selection Processes ◽  
Intercellular Cooperation ◽  
Multicellular Organisms ◽  
Different Levels

The major transitions approach in evolutionary biology has shown that the intercellular cooperation that characterizes multicellular organisms would never have emerged without some kind of multilevel selection. Relying on this view, the Evolutionary Somatic view of cancer considers cancer as a breakdown of intercellular cooperation and as a loss of the balance between selection processes that take place at different levels of organization (particularly single cell and individual organism). This seems an elegant unifying framework for healthy organism, carcinogenesis, tumour proliferation, metastasis and other phenomena such as ageing. However, the gene-centric version of Darwinian evolution, which is often adopted in cancer research, runs into empirical problems: proto-tumoural and tumoural features in precancerous cells that would undergo ‘natural selection’ have proved hard to demonstrate; cells are radically context-dependent, and some stages of cancer are poorly related to genetic change. Recent perspectives propose that breakdown of intercellular cooperation could depend on ‘fields’ and other higher-level phenomena, and could be even mutations independent. Indeed, the field would be the context, allowing (or preventing) genetic mutations to undergo an intra-organism process analogous to natural selection. The complexities surrounding somatic evolution call for integration between multiple incomplete frameworks for interpreting intercellular cooperation and its pathologies.

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