scholarly journals Spatial resource heterogeneity creates local hotspots of evolutionary potential

2017 ◽  
Author(s):  
Emily Dolson ◽  
Charles Ofria
Keyword(s):  
Explanatory Power ◽  
Biological Evolution ◽  
Biological Data ◽  
Heterogeneous Environments ◽  
Digital Evolution ◽  
Resource Heterogeneity ◽  
Evolutionary Potential ◽  
Local Conditions ◽  
Local Diversity ◽  
Novel Traits

AbstractDo local conditions influence evolution’s ability to produce new traits? Biological data demonstrate that evolutionary processes can be profoundly influenced by local conditions. However, the evolution of novel traits has not been addressed in this context, owing in part to the challenges of performing the necessary experiments with natural organisms. We conduct in silico experiments with the Avida Digital Evolution Platform to address this question. We created eight different spatially heterogeneous environments and ran 100 replicates in each. Within each environment, we examined the distribution of locations where nine different focal traits first evolved. Using spatial statistics methods, we identified regions within each environment that had significantly elevated probabilities of containing the first organism with a given trait (i.e. hotspots of evolutionary potential). Having demonstrated the presence of many such hotspots, we explored three potential mechanisms that could drive the formation of these patterns: proximity of specific resources, variation in local diversity, and variation in the sequence of locations the members of an evolutionary lineage occupy. Resource proximity and local diversity appear to have minimal explanatory power. Lineage paths through space, however, show some promising preliminary trends. If we can understand the processes that create evolutionary hotspots, we will be able to craft environments that are more effective at evolving targeted traits. This capability would be useful both to evolutionary computation, and to efforts to guide biological evolution.

On the Adaptive Cycle of Transformational Change: A Proposal for a Panarchical Expansion of Escalation Theory

2008 ◽  
Vol 14 ◽  
pp. 335-355
Author(s):  
Gregory P. Dietl
Keyword(s):  
Explanatory Power ◽  
Biological Evolution ◽  
Transformational Change ◽  
Robert Frost ◽  
Systems Ecology ◽  
Adaptive Cycle ◽  
Nested Sets ◽  
The Difference ◽  
The One ◽  
Ecologically Sustainable

An outstanding challenge with broad implications for an ecologically sustainable future is to understand how living systems—whether natural or social—balance opportunity and constraint in a given environment. In this paper, I compare the proposed mechanics of a heuristic developed to explain transformational change in systems ecology with various paleontological patterns and hypotheses for its conceptual homology and thus explanatory power in causal terms. The adaptive cycle heuristic, which has potential to influence current environmental and natural resources law and policy, has two components: 1) cycles that alternate between long periods of growth and shorter periods that create opportunities for innovation (new structures or conditions that become economically successful), and 2) the interaction of nested sets of such cycles (panarchies) across space and time scales. I critically evaluate three basic underlying tenets of the adaptive cycle related to the circumstances of innovation—empty niche space, competition and availability of resources—because of their importance to the development of a theoretical framework for understanding the ecological dimension of opportunity in biological evolution. I conclude that not all of the proposed mechanics and observed phenomenology of the adaptive cycle are appropriate in biological evolution. I draw insight, however, from the hierarchical nature of the heuristic to outline a “panarchical” conceptualization of the escalation hypothesis; I identify self-organization, emergence, selection and adaptation, and feedback as phenomena that are held in common across systems and scales, which influence how entities in the economic hierarchy of life arise, interact and evolve.Two roads diverged in a wood, and I, I took the one less traveled by, and that has made all the difference.Robert Frost.Every system either finds a way to develop or else collapses.Aleksander Solzhenitsyn

scholarly journals The Boundedness Illusion: Asymptotic projections from early evolution underestimate evolutionary potential

2018 ◽  
Author(s):  
Michael J Wiser ◽  
Emily L Dolson ◽  
Anya Vostinar ◽  
Richard E Lenski ◽  
Charles Ofria
Keyword(s):  
Early Evolution ◽  
Digital Evolution ◽  
Evolutionary Potential ◽  
Holy Grail ◽  
End Point ◽  
Evolution Experiment ◽  
Best Fit

Open-ended evolution researchers seek to create systems that continually produce new evolutionary outcomes, attempting to reflect the power and diversity of evolution in nature. The specific metrics used (novelty, complexity, diversity, etc) vary by researcher, but the holy grail would be a system where any of these can accumulate indefinitely. Of course, one challenge that we face in reaching this goal is even recognizing if we have succeeded. To determine the evolutionary potential of a system, we must conduct finite experiments; based on their results we can predict how we would expect evolution to progress were it to continue. Here we examine how such predictions might be made and how accurate they might be. We focus on predicting fitness; this metric is often easy to calculate, and correlated with increases in traits like novelty and complexity. For each run in a simple digital evolution experiment, we find the best fit to measured values of fitness, and demonstrate that projecting this fit out usually predicts that fitness will be constrained by an asymptote. Upon extending the experiment, however, we see that fitness often far exceeds this asymptote, belying the boundedness that it implies. Extending past a premature end point allows us to see beyond this "boundedness illusion"

scholarly journals The Boundedness Illusion: Asymptotic projections from early evolution underestimate evolutionary potential

2018 ◽  
Author(s):  
Michael J Wiser ◽  
Emily L Dolson ◽  
Anya Vostinar ◽  
Richard E Lenski ◽  
Charles Ofria
Keyword(s):  
Early Evolution ◽  
Digital Evolution ◽  
Evolutionary Potential ◽  
Holy Grail ◽  
End Point ◽  
Evolution Experiment ◽  
Best Fit

Open-ended evolution researchers seek to create systems that continually produce new evolutionary outcomes, attempting to reflect the power and diversity of evolution in nature. The specific metrics used (novelty, complexity, diversity, etc) vary by researcher, but the holy grail would be a system where any of these can accumulate indefinitely. Of course, one challenge that we face in reaching this goal is even recognizing if we have succeeded. To determine the evolutionary potential of a system, we must conduct finite experiments; based on their results we can predict how we would expect evolution to progress were it to continue. Here we examine how such predictions might be made and how accurate they might be. We focus on predicting fitness; this metric is often easy to calculate, and correlated with increases in traits like novelty and complexity. For each run in a simple digital evolution experiment, we find the best fit to measured values of fitness, and demonstrate that projecting this fit out usually predicts that fitness will be constrained by an asymptote. Upon extending the experiments, however, we see that fitness often far exceeds this asymptote, belying the boundedness that it implies. Extending past a premature end point allows us to see beyond this "boundedness illusion"

The Leeuwenhoek Lecture, 1979 Experiments in microbial evolution: new enzymes, new metabolic activities

1980 ◽  
Vol 207 (1169) ◽  
pp. 385-404 ◽  
Keyword(s):  
Biological Evolution ◽  
Gene Mutations ◽  
Enzyme Synthesis ◽  
Microbial Evolution ◽  
Gene Duplications ◽  
Evolutionary Potential ◽  
Catabolic Pathways ◽  
Bacterial Populations ◽  
Catabolic Genes ◽  
Metabolic Activities

Biological evolution has resulted in a richness and diversity of species. Among microorganisms this is most evident in the wealth and diversity of biochemical transformations. Evidence for evolutionary relationships may be obtained from comparative studies, but with microorganisms it is also possible to follow evolution in action. Microbial populations adapt rapidly to changes in the environment and the evolution of new metabolic activities can be observed in laboratory experiments. The enzymes of many catabolic pathways are synthesized in response to the presence of inducing substrates. New catabolic activities may be acquired by mutations in regulatory genes resulting in alterations in the specificity of induction, or in enzyme synthesis in the absence of inducer. Mutations in structural genes may give rise to enzymes with altered substrate specificities. In bacteria, catabolic genes may be carried on plasmids and the exchange of plasmids among bacterial populations increases the evolutionary potential. Experiments in microbial evolution have produced strains with novel catabolic activities involving regulatory or structural gene mutations, gene duplications and plasmid exchange. Enzymes studied in this way include amidase, ribitol dehydrogenase, evolved (β-galactosidase, and enzymes of the catabolic pathways for pentoses and pentitols and haloaromatic compounds.

scholarly journals The Boundedness Illusion: Asymptotic projections from early evolution underestimate evolutionary potential

2018 ◽  
Author(s):  
Michael J Wiser ◽  
Emily L Dolson ◽  
Anya Vostinar ◽  
Richard E Lenski ◽  
Charles Ofria
Keyword(s):  
Early Evolution ◽  
Digital Evolution ◽  
Evolutionary Potential ◽  
Holy Grail ◽  
End Point ◽  
Evolution Experiment ◽  
Best Fit

Open-ended evolution researchers seek to create systems that continually produce new evolutionary outcomes, attempting to reflect the power and diversity of evolution in nature. The specific metrics used (novelty, complexity, diversity, etc) vary by researcher, but the holy grail would be a system where any of these can accumulate indefinitely. Of course, one challenge that we face in reaching this goal is even recognizing if we have succeeded. To determine the evolutionary potential of a system, we must conduct finite experiments; based on their results we can predict how we would expect evolution to progress were it to continue. Here we examine how such predictions might be made and how accurate they might be. We focus on predicting fitness; this metric is often easy to calculate, and correlated with increases in traits like novelty and complexity. For each run in a simple digital evolution experiment, we find the best fit to measured values of fitness, and demonstrate that projecting this fit out usually predicts that fitness will be constrained by an asymptote. Upon extending the experiment, however, we see that fitness often far exceeds this asymptote, belying the boundedness that it implies. Extending past a premature end point allows us to see beyond this "boundedness illusion"

Plant families exhibit unique geographic trends in C4 richness and cover

2021 ◽  
Author(s):  
Samantha Munroe ◽  
Francesca A McInerney ◽  
Greg Guerin ◽  
Jake Andrae ◽  
Nina Welti ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Plant Cover ◽  
Explanatory Power ◽  
Tree Cover ◽  
C4 Plant ◽  
Local Conditions ◽  
Plant Families ◽  
The Relationship ◽  
Proportional Cover ◽  
Local Parameters

Numerous studies have analysed the relationship between C4 plant cover and climate. However, few have examined how different C4 taxa vary in their response to climate, or how environmental factors alter C4:C3 abundance. Here we investigate (a) how proportional C4 plant cover and richness (relative to C3) responds to changes in climate and local environmental factors, and (b) if this response is consistent among families. Proportional cover and richness of C4 species were determined at 541 one-hectare plots across Australia for 14 families. C4 cover and richness of the most common and abundant families were regressed against climate and local parameters. C4 cover and richness in Poaceae and Cyperaceae were strongly positively correlated with January temperatures, however C4 Cyperaceae occupied a more restricted temperature range. C4 Poaceae cover was also correlated with seasonal rainfall, but no such trends were identified in Cyperaceae. Soil pH and tree cover modified relative C4 cover in these families. Proportional C4 Euphorbiaceae and Chenopodiaceae cover and richness were weakly correlated with climate, but were more strongly influenced by local environmental factors, including tree cover and soil texture. However, the explanatory power of C4 Euphorbiaceae and Chenopodiaceae models were poor. Results demonstrate the unique relationships between different C4 taxa and climate, and the significant modifying effects of environmental factors on C4 distribution. Our work also reveals C4 families will not exhibit consistent responses to perturbations in climate or local conditions. These results have substantial implications for predicting C4 cover over global, continental and regional areas. This preprint is current under review following revisions with the journal Oecologia.

The Evolution of Technological Knowledge: Reflections on Technological Innovation as an Evolutionary Process

2002 ◽  
Author(s):  
Brian J. Loasby
Keyword(s):  
Technological Innovation ◽  
Rational Choice Theory ◽  
Choice Theory ◽  
Explanatory Power ◽  
Biological Evolution ◽  
Evolutionary Process ◽  
Psychological Theory ◽  
Selection Processes ◽  
Growth Of Knowledge ◽  
New Ideas

This chapter analyses Technological Innovation as an Evolutionary Process, a book that explores the analogy between technical innovation and biological evolution, and whether such an analogy could be developed from a ‘metaphor’ into a ‘model’. After discussing the explanatory power of ‘evolutionary reasoning’, the chapter describes an alternative approach to the analysis of technological innovation. It then presents an evolutionary argument for the growth of knowledge and explains how it differs from neo-Darwinism, and examines rational choice theory in relation to natural selection. It also looks at six elements of Adam Smith's psychological theory of the emergence and development of science: the motivation for generating new ideas; the generation of novelty and the ex-ante selection processes which guide its adoption or rejection; the role of aesthetic criteria both in guiding conjectures and in encouraging their acceptance; Smith's argument that connecting principles which seem to work well are widely diffused; the renewal of the evolutionary process; and the evolution of the evolutionary process itself. Finally, the chapter considers the implications of uncertainty for cognition and the growth of knowledge.

HR technology goal realization: predictors and consequences

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gary W. Florkowski
Keyword(s):  
Organizational Support ◽  
Structural Equation ◽  
Positive Impact ◽  
Explanatory Power ◽  
Equation Modeling ◽  
Management Support ◽  
Local Conditions ◽  
Content Type ◽  
Innovation Climate ◽  
Goal Realization

PurposeDrawing on the HR technology (HRT) and information systems (IS) literatures, this study seeks to identify macro-level factors that influence the performance of HRT systems. A second objective is to assess the relative contribution that HRT goal realization makes to organizational satisfaction with HR services.Design/methodology/approachThis investigation draws on a web-based survey of 169 US and Canadian firms targeting HR executives as key informants. Structural equation modeling (SEM) tested the roles that organizational support, capabilities and aspects of the environment play in technology goal attainment and collective satisfaction with HR services. Exploratory factor analysis (EFA) evaluated the properties of several key scales and supported their usage. Moderated regression analysis further assessed whether HRT age influenced certain relationships.FindingsAs predicted, system goal realization was positively related to the level of support from an HRT champion and an HR innovation climate, while being negatively related to HRT mimetic isomorphism. HR service satisfaction, in turn, was positively related to HRT goal realization, the HR innovation climate and HR environmental munificence. It also was determined that HRT champions had a stronger positive impact on goal realization for younger technology portfolios. This too was expected.Research limitations/implicationsExternal validity would be strengthened by not only increasing sample sizes for the USA and Canada, but also targeting more nations for data collection. The model's explanatory power may also be enhanced by improving the measurement of several predictors (e.g. top management support, absorptive capacity), as well incorporating constructs that focus on users (e.g. group potency, collective efficacy).Practical implicationsThese findings underscore the need to proactively screen and structure the surrounding environment to facilitate portfolio success. Greater emphasis must be placed on (1) identifying and empowering HRT champions, (2) fostering an innovation climate in the HR function and (3) conditioning HRT purchases on “mindful” adoption. Doing so should not only increase the prospects of realizing goals, but also elevate satisfaction with HR services.Originality/valueThis is the first study to formally assess the effects that organizational and environmental context have on overall HRT systems performance. Prior research has focused on linking the local conditions of individual users to their perceptions and usage of HR technologies.

scholarly journals Natural selection drives population divergence for local adaptation in a wheat pathogen

2019 ◽  
Author(s):  
Danilo Pereira ◽  
Daniel Croll ◽  
Patrick C. Brunner ◽  
Bruce A. McDonald
Keyword(s):  
Growth Rates ◽  
Common Garden ◽  
High Temperature Stress ◽  
Population Divergence ◽  
Stabilizing Selection ◽  
Evolutionary Potential ◽  
Local Conditions ◽  
Evolutionary Forces ◽  
Different Temperatures ◽  
Parastagonospora Nodorum

AbstractEvolution favors the emergence of locally-adapted optimum phenotypes that are likely to differ across a wide array of environmental conditions. The emergence of favorable adaptive characteristics is accelerated in agricultural pathogens due to the unique properties of agro-ecosystems. We performed a QST - FST comparison using 164 strains of Parastagonospora nodorum sampled from eight global field populations to disentangle the predominant evolutionary forces driving population divergence in a wheat pathogen. We used digital image analysis to obtain quantitative measurements of growth rate and melanization at different temperatures and under different fungicide concentrations in a common garden experiment. FST measures were based on complete genome sequences obtained for all 164 isolates. Our analyses indicated that all measured traits were under selection. Growth rates at 18°C and 24°C were under stabilizing selection (QST < FST), while diversifying selection (QST > FST) was the predominant evolutionary force affecting growth under fungicide and high temperature stress. Stabilizing selection (QST < FST) was the predominant force affecting melanization across the different environments. Melanin production increased at 30°C but was negatively correlated with higher growth rates, consistent with a trade-off under heat stress. Our results demonstrate that global populations of P. nodorum possess significant evolutionary potential to adapt to changing local conditions, including warmer temperatures and applications of fungicides.

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