Historical Contingency in Controlled Evolution

2014 ◽  
pp. 187-220
Author(s):  
Peter Schuster
Keyword(s):  
Historical Contingency

scholarly journals Historical contingency impacts on community assembly and ecosystem function in chemosynthetic marine ecosystems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dimitri Kalenitchenko ◽  
Erwan Peru ◽  
Pierre E. Galand
Keyword(s):  
Community Assembly ◽  
Sea Water ◽  
Marine Ecosystem ◽  
Marine Ecosystems ◽  
Metagenomic Sequencing ◽  
Historical Contingency ◽  
Historical Events ◽  
Species Sorting ◽  
Environmental Selection ◽  
Microbial Community Assembly

AbstractPredicting ecosystem functioning requires an understanding of the mechanisms that drive microbial community assembly. Many studies have explored microbial diversity extensively and environmental factors are thought to be the principal drivers of community composition. Community assembly is, however, also influenced by past conditions that might affect present-day assemblages. Historical events, called legacy effects or historical contingencies, remain poorly studied in the sea and their impact on the functioning of the communities is not known. We tested the influence, if any, of historical contingencies on contemporary community assembly and functions in a marine ecosystem. To do so, we verified if different inoculum communities colonizing the same substrate led to communities with different compositions. We inoculated wood with sea water microbes from different marine environments that differ in ecological and evolutionary history. Using 16S rRNA and metagenomic sequencing, it was demonstrated that historical contingencies change the composition and potential metabolisms of contemporary communities. The effect of historical events was transient, dominated by environmental selection as, over time, species sorting was a more important driver of community assembly. Our study shows not only that historical contingencies affect marine ecosystems but takes the analysis a step further by characterizing this effect as strong but transient.

Path Dependence

2017 ◽  
Author(s):  
Michelle Hegmon
Keyword(s):  
Decision Making ◽  
Path Dependence ◽  
General Level ◽  
Historical Contingency ◽  
Difficult Decision ◽  
Critical Junctures ◽  
Potential Applications ◽  
Path Dependent ◽  
Historical Sequences ◽  
Lock In

Path dependence concepts, thus far, have seen little application in archaeology, but they have great potential. At a general level, these concepts provide tools for theorizing historical sequences, such as patterns of settlement on a landscape and divergent historical traditions. Potential applications include issues of historical contingency in the late Rio Grande, settlement in the Mesa Verde region, and divergent trajectories in the post-Chaco period. Specific concepts from path dependence theory, including lock-in and critical junctures, are illustrated by an analysis of the growth of Hohokam irrigation, which exhibited a path-dependent trajectory. As archaeological study of path dependence builds awareness of the importance of decision-making on the future, it contributes to difficult decision-making in today’s world.

Helping the novel: Neoliberalism, self-help, and the narrating of the self in Mohsin Hamid’s How to Get Filthy Rich in Rising Asia

2016 ◽  
Vol 52 (1) ◽  
pp. 139-150 ◽  
Author(s):  
Angelia Poon
Keyword(s):  
Modern Technology ◽  
The Self ◽  
Individual Choice ◽  
The Novel ◽  
Historical Contingency ◽  
Narrative Strategies ◽  
Important Place ◽  
Realist Novel ◽  
Self Help ◽  
Vantage Points

Self-help books sell the myth of self-determinism, empowerment and the eternal hope of reinvention, reasons no doubt for their enormous popularity. In this article, I examine Pakistani-born Mohsin Hamid’s latest novel, How to Get Filthy Rich in Rising Asia (2013) which, with its catchy, hyperbolic title signalling its masquerade as a self-help book, openly and ironically advertises itself as a satire. The object of the novel’s satire is the capitalist, neoliberal notion of the self that is predicated on an overweening sense of control and complete agency. Neoliberal subjectivity endorses the care and transformation of the self in order to take best advantage of a market economy, since the means to achieving material affluence is seen simply as a matter of individual choice and personal will. In the novel, Hamid brings into productive tension the conventions and assumptions of the self-help genre with those of the more traditional realist novel in order to interrogate not just the neoliberal self but the very ways in which the self is narrated and constructed. Engaging in particular with the affordances of technology in his novel as a thematic, Hamid appropriates the vantage points and perspectival positions made possible by modern technology to undermine the solipsistic self of the self-help book. He further exploits the narrative energies of the novel form to foreground a sense of historical contingency to lay bare various modes of self-constitution and self-narration. Through his use of metatextual narrative strategies, Hamid raises fundamental questions about the genre of the novel itself and the ways in which it is intimately invested in the insinuation of the development of a self. These questions, I argue, ultimately underline his affirmation of the novel’s important place and the ethical role it can play at this contemporary moment of late and global capitalism.

scholarly journals Habitability of galaxies and the application of merger trees in astrobiology

2019 ◽  
pp. 25-43
Author(s):  
N. Stojkovic ◽  
B. Vukotic ◽  
M.M. Cirkovic
Keyword(s):  
Spatial Resolution ◽  
Research Method ◽  
Large Scale ◽  
High Mass ◽  
Historical Contingency ◽  
Causal Factors ◽  
New Era ◽  
Present Epoch ◽  
General Issue ◽  
Habitable Zones

Galaxies represent the main form of organization of matter in our universe. Therefore, they are of obvious interest for the new multidisciplinary field of astrobiology. In particular, to study habitability of galaxies represents one of the main emerging challenges of theoretical and numerical astrobiology. Its theoretical underpinnings are, however, often confused and vague. Here we present a systematic attempt to list and categorize major causal factors playing a role in emergent habitability of galaxies. Furthermore, we argue that the methodology of cosmological merger trees is particularly useful in delineating what are systematic and lawful astrobiological properties of galaxies at present epoch vs. those which are product of historical contingency and, in particular, interaction with wider extragalactic environment. Employing merger trees extracted from cosmological N-body simulations as a new and promising research method for astrobiology has been pioneered by Stanway et al. (2018). We analyse the general issue of applicability of merger trees and present preliminary results on a set of trees extracted from the Illustris Project. In a sense, this approach is directly complementary to using large-scale cosmological simulations to study habitable zones of individual galaxies with high mass/spatial resolution; taken together, they usher a new era of synergy and synthesis between cosmology and astrobiology.

scholarly journals Evolutionary assembly patterns of prokaryotic genomes

2015 ◽  
Author(s):  
Maximilian O. Press ◽  
Christine Queitsch ◽  
Elhanan Borenstein
Keyword(s):  
Evolutionary Constraints ◽  
Historical Contingency ◽  
Phenotypic Characters ◽  
Functional Relationships ◽  
Evolutionary Innovation ◽  
Gene Level ◽  
Prokaryotic Genomes ◽  
Evolutionary Paths ◽  
Evolution Of Proteins ◽  
Sequence Substitution

AbstractEvolutionary innovation must occur in the context of some genomic background, which limits available evolutionary paths. For example, protein evolution by sequence substitution is constrained by epistasis between residues. In prokaryotes, evolutionary innovation frequently happens by macrogenomic events such as horizontal gene transfer (HGT). Previous work has suggested that HGT can be influenced by ancestral genomic content, yet the extent of such gene-level constraints has not yet been systematically characterized. Here, we evaluated the evolutionary impact of such constraints in prokaryotes, using probabilistic ancestral reconstructions from 634 extant prokaryotic genomes and a novel framework for detecting evolutionary constraints on HGT events. We identified 8,228 directional dependencies between genes, and demonstrated that many such dependencies reflect known functional relationships, including, for example, evolutionary dependencies of the photosynthetic enzyme RuBisCO. Modeling all dependencies as a network, we adapted an approach from graph theory to establish chronological precedence in the acquisition of different genomic functions. Specifically, we demonstrated that specific functions tend to be gained sequentially, suggesting that evolution in prokaryotes is governed by functional assembly patterns. Finally, we showed that these dependencies are universal rather than clade-specific and are often sufficient for predicting whether or not a given ancestral genome will acquire specific genes. Combined, our results indicate that evolutionary innovation via HGT is profoundly constrained by epistasis and historical contingency, similar to the evolution of proteins and phenotypic characters, and suggest that the emergence of specific metabolic and pathological phenotypes in prokaryotes can be predictable from current genomes.

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