scholarly journals How phenotypic convergence arises in experimental evolution

2019 ◽  
Author(s):  
Pedro Simões ◽  
Inês Fragata ◽  
Josiane Santos ◽  
Marta A. Santos ◽  
Mauro Santos ◽  
...  
Keyword(s):  
Experimental Evolution ◽  
Evolutionary Dynamics ◽  
Short Term ◽  
Common Environment ◽  
Evolutionary Trajectory ◽  
Trajectory Approach ◽  
Evolutionary Trajectories ◽  
Core Issue ◽  
Evolutionary Convergence ◽  
Phenotypic Convergence

AbstractEvolutionary convergence is a core issue in the study of adaptive evolution, as well as a highly debated topic at present. Few studies have analyzed this issue using a “real-time” or evolutionary trajectory approach. Do populations that are initially differentiated converge to a similar adaptive state when experiencing a common novel environment?Drosophila subobscurapopulations founded from different locations and years showed initial differences and variation in evolutionary rates in several traits during short-term (∼20 generations) laboratory adaptation. Here we extend that analysis to 40 more generations to analyze (1) how differences in evolutionary dynamics between populations change between shorter and longer time spans, and (2) whether evolutionary convergence occurs after sixty generations of evolution in a common environment. We found substantial variation in longer-term evolutionary trajectories and differences between short and longer-term evolutionary dynamics. Though we observed pervasive patterns of convergence towards the character values of long-established populations, populations still remain differentiated for several traits at the final generations analyzed. This pattern might involve transient divergence, as we report in some cases, indicating that more generations should lead to final convergence. These findings highlight the importance of longer-term studies for understanding convergent evolution.

scholarly journals Adaptation to a novel predator inDrosophila melanogaster: How well are we able to predict evolutionary responses?

2014 ◽  
Author(s):  
Michael DeNieu ◽  
William Pitchers ◽  
Ian Dworkin
Keyword(s):  
Natural Selection ◽  
Experimental Evolution ◽  
Phenotypic Selection ◽  
Ancestral Population ◽  
Wing Size ◽  
Short Term ◽  
Heritable Variation ◽  
Size And Shape ◽  
Evolutionary Trajectories ◽  
Short Term Prediction

Evolutionary theory is sufficiently well developed to allow for short-term prediction of evolutionary trajectories. In addition to the presence of heritable variation, prediction requires knowledge of the form of natural selection on relevant traits. While many studies estimate the form of natural selection, few examine the degree to which traits evolve in the predicted direction. In this study we examine the form of natural selection imposed by mantid predation on wing size and shape in the fruitfly,Drosophila melanogaster. We then evolve populations ofD. melanogasterunder predation pressure, and examine the extent to which wing size and shape have responded in the predicted direction. We demonstrate that wing form partially evolves along the predicted vector from selection, more so than for control lineages. Furthermore, we re-examined phenotypic selection after ~30 generations of experimental evolution. We observed that the magnitude of selection on wing size and shape was diminished in populations evolving with mantid predators, while the direction of the selection vector differed from that of the ancestral population for shape. We discuss these findings in the context of the predictability of evolutionary responses, and the need for fully multivariate approaches.

scholarly journals Competitive history shapes rapid evolution in a seasonal climate

2021 ◽  
Vol 118 (6) ◽  
pp. e2015772118
Author(s):  
Tess Nahanni Grainger ◽  
Seth M. Rudman ◽  
Paul Schmidt ◽  
Jonathan M. Levine
Keyword(s):  
Interspecific Competition ◽  
Evolutionary Dynamics ◽  
Critical Role ◽  
Rapid Evolution ◽  
Climatic Conditions ◽  
Phenotypic Change ◽  
Evolutionary Trajectory ◽  
History Of ◽  
Evolutionary Trajectories ◽  
Faster Development

Eco-evolutionary dynamics will play a critical role in determining species’ fates as climatic conditions change. Unfortunately, we have little understanding of how rapid evolutionary responses to climate play out when species are embedded in the competitive communities that they inhabit in nature. We tested the effects of rapid evolution in response to interspecific competition on subsequent ecological and evolutionary trajectories in a seasonally changing climate using a field-based evolution experiment with Drosophila melanogaster. Populations of D. melanogaster were either exposed, or not exposed, to interspecific competition with an invasive competitor, Zaprionus indianus, over the summer. We then quantified these populations’ ecological trajectories (abundances) and evolutionary trajectories (heritable phenotypic change) when exposed to a cooling fall climate. We found that competition with Z. indianus in the summer affected the subsequent evolutionary trajectory of D. melanogaster populations in the fall, after all interspecific competition had ceased. Specifically, flies with a history of interspecific competition evolved under fall conditions to be larger and have lower cold fecundity and faster development than flies without a history of interspecific competition. Surprisingly, this divergent fall evolutionary trajectory occurred in the absence of any detectible effect of the summer competitive environment on phenotypic evolution over the summer or population dynamics in the fall. This study demonstrates that competitive interactions can leave a legacy that shapes evolutionary responses to climate even after competition has ceased, and more broadly, that evolution in response to one selective pressure can fundamentally alter evolution in response to subsequent agents of selection.

scholarly journals Modelling the On-going Natural Selection of Educational Attainment in Contemporary Societies

2019 ◽  
Author(s):  
Ze Hong
Keyword(s):  
Educational Attainment ◽  
Simulation Model ◽  
Evolutionary Dynamics ◽  
Developed Countries ◽  
Genetic Component ◽  
Past Century ◽  
Human Populations ◽  
Short Term ◽  
Evolutionary Trajectory ◽  
Cultural Component

AbstractThere has been substantial increase in education attainment (EA) in both developing and developed countries over the past century. I present a simulation model to examine the potential evolutionary trajectories of EA under current selective pressure in western populations. With the assumption that EA is negatively correlated with fitness and has both a genetic component and a cultural component, I show that when prestige-biased transmission of the EA (i.e. people with more education are more likely to be copied) is present, the phenotype of EA is likely to keep increasing in the short term, yet the genetic component of EA may be undergoing a constant decline and eventually lead to an overall decrease in the phenotype.Significance statementContemporary humans live in very different environments from our ancestors and are subject to very different selective forces. The future evolutionary trajectory of current human populations is thus of both intellectual and pragmatic importance. The present simulation model sheds light on the short-term evolutionary dynamics of educational attainment, and demonstrates the significant contribution of systematically transmitted human culture in shaping the evolutionary paths and producing non-intuitive evolutionary outcomes.

scholarly journals Somatic deficiency causes reproductive parasitism in a fungus

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexey A. Grum-Grzhimaylo ◽  
Eric Bastiaans ◽  
Joost van den Heuvel ◽  
Cristina Berenguer Millanes ◽  
Alfons J. M. Debets ◽  
...  
Keyword(s):  
Neurospora Crassa ◽  
Experimental Evolution ◽  
Evolutionary Dynamics ◽  
Genetic Load ◽  
Wild Type ◽  
Fusion Frequency ◽  
Somatic Fusion ◽  
Extensive Variation ◽  
Reproductive Parasitism ◽  
Multicellular Organisms

AbstractSome multicellular organisms can fuse because mergers potentially provide mutual benefits. However, experimental evolution in the fungus Neurospora crassa has demonstrated that free fusion of mycelia favours cheater lineages, but the mechanism and evolutionary dynamics of this exploitation are unknown. Here we show, paradoxically, that all convergently evolved cheater lineages have similar fusion deficiencies. These mutants are unable to initiate fusion but retain access to wild-type mycelia that fuse with them. This asymmetry reduces cheater-mutant contributions to somatic substrate-bound hyphal networks, but increases representation of their nuclei in the aerial reproductive hyphae. Cheaters only benefit when relatively rare and likely impose genetic load reminiscent of germline senescence. We show that the consequences of somatic fusion can be unequally distributed among fusion partners, with the passive non-fusing partner profiting more. We discuss how our findings may relate to the extensive variation in fusion frequency of fungi found in nature.

scholarly journals Evolution of a predator-induced, nonlinear reaction norm

2017 ◽  
Vol 284 (1861) ◽  
pp. 20170859 ◽  
Author(s):  
Mauricio J. Carter ◽  
Martin I. Lind ◽  
Stuart R. Dennis ◽  
William Hentley ◽  
Andrew P. Beckerman
Keyword(s):  
Evolutionary Dynamics ◽  
Daphnia Pulex ◽  
Reaction Norm ◽  
Maximum Response ◽  
Selective Predation ◽  
Evolutionary Trajectory ◽  
Defensive Reaction ◽  
Selection Gradients ◽  
Hunting Strategies ◽  
Evolutionary Response

Inducible, anti-predator traits are a classic example of phenotypic plasticity. Their evolutionary dynamics depend on their genetic basis, the historical pattern of predation risk that populations have experienced and current selection gradients. When populations experience predators with contrasting hunting strategies and size preferences, theory suggests contrasting micro-evolutionary responses to selection. Daphnia pulex is an ideal species to explore the micro-evolutionary response of anti-predator traits because they face heterogeneous predation regimes, sometimes experiencing only invertebrate midge predators and other times experiencing vertebrate fish and invertebrate midge predators. We explored plausible patterns of adaptive evolution of a predator-induced morphological reaction norm. We combined estimates of selection gradients that characterize the various habitats that D. pulex experiences with detail on the quantitative genetic architecture of inducible morphological defences. Our data reveal a fine scale description of daphnid defensive reaction norms, and a strong covariance between the sensitivity to cues and the maximum response to cues. By analysing the response of the reaction norm to plausible, predator-specific selection gradients, we show how in the context of this covariance, micro-evolution may be more uniform than predicted from size-selective predation theory. Our results show how covariance between the sensitivity to cues and the maximum response to cues for morphological defence can shape the evolutionary trajectory of predator-induced defences in D. pulex .

scholarly journals The rapid in vivo evolution of Pseudomonas aeruginosa in ventilator-associated pneumonia patients leads to attenuated virulence

Open Biology ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. 170029 ◽  
Author(s):  
Ke Wang ◽  
Yi-qiang Chen ◽  
May M. Salido ◽  
Gurjeet S. Kohli ◽  
Jin-liang Kong ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Opportunistic Pathogen ◽  
Ventilator Associated Pneumonia ◽  
Loss Of Function ◽  
Short Term ◽  
Airway Infections ◽  
Evolutionary Trajectories ◽  
Human Airways ◽  
Late Stages

Pseudomonas aeruginosa is an opportunistic pathogen that causes severe airway infections in humans. These infections are usually difficult to treat and associated with high mortality rates. While colonizing the human airways, P. aeruginosa could accumulate genetic mutations that often lead to its better adaptability to the host environment. Understanding these evolutionary traits may provide important clues for the development of effective therapies to treat P. aeruginosa infections. In this study, 25 P. aeruginosa isolates were longitudinally sampled from the airways of four ventilator-associated pneumonia (VAP) patients. Pacbio and Illumina sequencing were used to analyse the in vivo evolutionary trajectories of these isolates. Our analysis showed that positive selection dominantly shaped P. aeruginosa genomes during VAP infections and led to three convergent evolution events, including loss-of-function mutations of lasR and mpl , and a pyoverdine-deficient phenotype. Specifically, lasR encodes one of the major transcriptional regulators in quorum sensing, whereas mpl encodes an enzyme responsible for recycling cell wall peptidoglycan. We also found that P. aeruginosa isolated at late stages of VAP infections produce less elastase and are less virulent in vivo than their earlier isolated counterparts, suggesting the short-term in vivo evolution of P. aeruginosa leads to attenuated virulence.

scholarly journals Chance, contingency, and necessity in the experimental evolution of ancestral proteins

2020 ◽  
Author(s):  
Victoria Cochran Xie ◽  
Jinyue Pu ◽  
Brian P.H. Metzger ◽  
Joseph W. Thornton ◽  
Bryan C. Dickinson
Keyword(s):  
Protein Evolution ◽  
Experimental Evolution ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Sequence Evolution ◽  
Protein Protein Interaction ◽  
Evolutionary Trajectories ◽  
Historical Moment ◽  
Related Proteins ◽  
Ancestral Protein

SUMMARYThe extent to which chance and contingency shaped the sequence outcomes of protein evolution is largely unknown. To directly characterize the causes and consequences of chance and contingency, we combined directed evolution with ancestral protein reconstruction. By repeatedly selecting a phylogenetic series of ancestral proteins in the B-cell lymphoma-2 family to evolve the same protein-protein interaction specificities that existed during history, we show that contingency and chance interact to make sequence evolution almost entirely unpredictable over the timescale of metazoan evolution. At any historical moment, multiple sets of mutations can alter or maintain specificity, and chance decides which ones occur. Contingency arises because historical sequence substitutions epistatically altered which mutations are compatible with new or ancestral functions. Evolutionary trajectories launched from different ancestors therefore lead to dramatically different outcomes over phylogenetic time, with virtually no mutations occurring repeatedly in distantly related proteins, even under identical selection conditions.

scholarly journals Chaos and the (un)predictability of evolution in a changing environment

2017 ◽  
Author(s):  
Artur Rego-Costa ◽  
Florence Débarre ◽  
Luis-Miguel Chevin
Keyword(s):  
Evolutionary Dynamics ◽  
Initial Conditions ◽  
Strong Dependence ◽  
Environmental Stochasticity ◽  
Phenotypic Evolution ◽  
Evolutionary System ◽  
Chaotic Oscillations ◽  
Changing Environment ◽  
Environmental Forcing ◽  
Evolutionary Trajectories

Among the factors that may reduce the predictability of evolution, chaos, characterized by a strong dependence on initial conditions, has received much less attention than randomness due to genetic drift or environmental stochasticity. It was recently shown that chaos in phenotypic evolution arises commonly under frequency-dependent selection caused by competitive interactions mediated by many traits. This result has been used to argue that chaos should often make evolutionary dynamics unpredictable. However, populations also evolve largely in response to external changing environments, and such environmental forcing is likely to influence the outcome of evolution in systems prone to chaos. We investigate how a changing environment causing oscillations of an optimal phenotype interacts with the internal dynamics of an eco-evolutionary system that would be chaotic in a constant environment. We show that strong environmental forcing can improve the predictability of evolution, by reducing the probability of chaos arising, and by dampening the magnitude of chaotic oscillations. In contrast, weak forcing can increase the probability of chaos, but it also causes evolutionary trajectories to track the environment more closely. Overall, our results indicate that, although chaos may occur in evolution, it does not necessarily undermine its predictability.

scholarly journals Strong evolutionary convergence of receptor-binding protein spike between COVID-19 and SARS-related coronaviruses

2020 ◽  
Author(s):  
Yonghua Wu
Keyword(s):  
Receptor Binding ◽  
Molecular Basis ◽  
Acid Sites ◽  
Spike Protein ◽  
Receptor Binding Domain ◽  
Angiotensin Converting Enzyme 2 ◽  
Partner Protein ◽  
Evolutionary Convergence ◽  
Genome Level ◽  
Phenotypic Convergence

AbstractCoronavirus Disease 2019 (COVID-19) and severe acute respiratory syndrome (SARS)-related coronaviruses (e.g., 2019-nCoV and SARS-CoV) are phylogenetically distantly related, but both are capable of infecting human hosts via the same receptor, angiotensin-converting enzyme 2, and cause similar clinical and pathological features, suggesting their phenotypic convergence. Yet, the molecular basis that underlies their phenotypic convergence remains unknown. Here, we used a recently developed molecular phyloecological approach to examine the molecular basis leading to their phenotypic convergence. Our genome-level analyses show that the spike protein, which is responsible for receptor binding, has undergone significant Darwinian selection along the branches related to 2019-nCoV and SARS-CoV. Further examination shows an unusually high proportion of evolutionary convergent amino acid sites in the receptor binding domain (RBD) of the spike protein between COVID-19 and SARS-related CoV clades, leading to the phylogenetic uniting of their RBD protein sequences. In addition to the spike protein, we also find the evolutionary convergence of its partner protein, ORF3a, suggesting their possible co-evolutionary convergence. Our results demonstrate a strong adaptive evolutionary convergence between COVID-19 and SARS-related CoV, possibly facilitating their adaptation to similar or identical receptors. Finally, it should be noted that many observed bat SARS-like CoVs that have an evolutionary convergent RBD sequence with 2019-nCoV and SARS-CoV may be pre-adapted to human host receptor ACE2, and hence would be potential new coronavirus sources to infect humans in the future.

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