Bee, hummingbird, or mixed-pollinated Salvia species mirror pathways to pollination optimization: a morphometric analysis based on the Pareto front concept

Botany ◽  
2017 ◽  
Vol 95 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Marina M. Strelin ◽  
Federico Sazatornil ◽  
Santiago Benitez-Vieyra ◽  
Mariano Ordano
Keyword(s):  
Pareto Front ◽  
Individual Contribution ◽  
Trade Off ◽  
Flower Shape ◽  
Trade Offs ◽  
Hummingbird Pollination ◽  
Joint Contribution ◽  
Pollination Systems ◽  
Flower Structures

Optimization of flower phenotypes to ensure pollination by agents differing in their match with fertile flower structures can involve fitness trade-offs if the aspects of the phenotype that enhance the fitness contribution of one pollinator are detrimental for pollination by the other agents. If these trade-offs are substantial, flower optimization for specialized pollination is expected. However, optimization for generalized pollination may also take place in trade-off scenarios, as long as the joint contribution of two or more types of pollinators to global pollination fitness is greater than each individual contribution. We used an observational approach to evaluate the role of pollination fitness trade-offs in flower trait optimization, a matter seldom addressed because of the difficulties in conducting experiments. A pattern-searching tool based on the Pareto front concept, borrowed from the fields of economics and engineering, was used to test for fitness trade-off patterns in the flower shape of four Salvia (Lamiaceae) species. Two are pollinated exclusively either by bees or by hummingbirds; the remaining species have mixed-pollination systems, with varying contributions of bee and hummingbird pollination. The patterning of flower shape in this study suggests a bee–hummingbird pollination trade-off in Salvia, and the optimization of generalized flower shapes.

Are speed/accuracy trade-offs caused by neuromotor noise, or not?

1997 ◽  
Vol 20 (2) ◽  
pp. 306-307 ◽  
Author(s):  
Willem P. De Jong ◽  
Gerard P. Van Galen
Keyword(s):  
Kinematic Model ◽  
Psychological Processes ◽  
Trade Off ◽  
Kinematic Theory ◽  
Trade Offs ◽  
Biomechanical Constraints ◽  
Speed Accuracy ◽  
Existing Data ◽  
The Way

Notwithstanding its overwhelming descriptive power for existing data, it is not clear whether the kinematic theory of Plamondon & Alimi could generate new insights into biomechanical constraints and psychological processes underlying the way organisms trade off speed for accuracy. The kinematic model should elaborate on the role of neuromotor noise and on biomechanical strategies for reducing endpoint variability related to such noise.

scholarly journals Herbivore Population Dynamics in Response to Plant Allocation Strategies

2021 ◽  
Author(s):  
Fang Ji ◽  
Christopher R Stieha ◽  
Karen C Abbott
Keyword(s):  
Food Limitation ◽  
Energetic Cost ◽  
Insect Herbivores ◽  
Insect Outbreaks ◽  
Tolerance Mechanisms ◽  
Trade Off ◽  
Trade Offs ◽  
Plant Allocation ◽  
Allocation Strategies

Abstract When herbivores feed, plants may respond by altering the quantity of edible biomass available to future feeders through mechanisms such as compensatory regrowth of edible structures or allocation of biomass to inedible reserves. Previous work showed that some forms of compensatory regrowth can drive insect outbreaks, but this work assumed regrowth occurred without any energetic cost to the plant. While this is a useful simplifying assumption for gaining preliminary insights, plants face an inherent trade-off between allocating energy to regrowth versus storage. Therefore, we cannot truly understand the role of compensatory regrowth in driving insect outbreaks without continuing on to more realistic scenarios. In this paper, we model the interaction between insect herbivores and plants that have a trade-off between compensatory regrowth and allocation to inedible reserves in response to herbivory. We found that the plant's allocation strategy, described in our model by parameters representing the strength of the overcompensatory response and the rates at which energy is stored and mobilized for growth, strongly affect whether herbivore outbreaks occur. Additional factors, such as the strength of food limitation and herbivore interference while feeding, influence the frequency of the outbreaks. Overall, we found a possible new role of overcompensation to promote herbivore fluctuations when it co-occurs with allocation to inedible reserves. We highlight the importance of considering trade-offs between tolerance mechanisms that plants use in response to herbivory by showing that new dynamics arise when different plant allocation strategies occur simultaneously.

The Future of Liberal Democracies, Pandemic Trade-Offs, and the Role of Social Sciences

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Radoslaw Markowski
Keyword(s):  
Social Sciences ◽  
Previous Knowledge ◽  
Liberal Democracies ◽  
Trade Off ◽  
Trade Offs ◽  
Norms And Values ◽  
The Future ◽  
Democratic Norms

The article is written in the form of an essay (for Dahrendorf Symposium), speculative in essence, yet based on the new selected evidence concerning peoples’ opinions and attitudes disclosed during the pandemic. It starts with remarks about predictions in social sciences and the complex problems in studying the shocks created by the Covid-19 pandemic. Second part is devoted to major challenges and trade-offs states, governments and citizens have to face currently, focusing on one particular which is crucial for the future quality of liberal democracies, that is a trade-off between democratic norms and values and surveillance practices. The article concludes with a discussion of several issues, which have become more salient during the pandemic, challenging our previous knowledge about them.

scholarly journals The diversity-ability trade-off in scientific problem solving

2021 ◽  
Author(s):  
Samuli Reijula ◽  
Jaakko Kuorikoski
Keyword(s):  
Problem Solving ◽  
High Ability ◽  
Trade Off ◽  
Scientific Problem ◽  
Scientific Problem Solving ◽  
Trade Offs ◽  
Problem Solvers ◽  
Problem Solving Task

According to the diversity-beats-ability theorem, groups of diverse problem solvers can outperform groups of high-ability problem solvers. We argue that the model introduced by Lu Hong and Scott Page (2004; see also Grim et al. 2019) is inadequate for exploring the trade-off between diversity and ability. This is because the model employs an impoverished implementation of the problem-solving task. We present a new version of the model which captures the role of ‘ability’ in a meaningful way, and use it to explore the trade-offs between diversity and ability in scientific problem solving.

scholarly journals Condition-dependent trade-offs maintain honest signaling: A laboratory experiment

2019 ◽  
Author(s):  
Szabolcs Számadó ◽  
Flóra Samu ◽  
Károly Takács
Keyword(s):  
Social Sciences ◽  
Laboratory Experiment ◽  
Theoretical Models ◽  
Honest Signaling ◽  
Handicap Principle ◽  
Trade Off ◽  
Honest Signals ◽  
Trade Offs ◽  
Dominant Paradigm

AbstractHow and why animals and humans signal reliably is a key issue in biology and social sciences. For many years the dominant paradigm in biology was the Handicap Principle. It claims a causal relationship between honesty and signal cost and thus predicts that honest signals have to be costly to produce. However, contrary to the Handicap Principle, game theoretical models predict that honest signaling is maintained by condition dependent signaling trade-offs and honest signals need not be costly at the equilibrium. Due to the difficulties of manipulating signal cost and signal trade-offs there is surprisingly little evidence to test these predictions either from biology or from social sciences. Here we conduct a human laboratory experiment with a two-factorial design to test the role of equilibrium signal cost vs. signalling trade-offs in the maintenance of honest communication. We have found that the trade-off condition has much higher influence on the reliability of communication than the equilibrium cost condition. The highest level of honesty was observed in the condition dependent trade-off condition as predicted by recent models. Negative production cost, i.e. fix benefit-contrary to the prediction of the Handicap Principle-promoted even higher level of honesty than the other type of costs under this condition.

scholarly journals Explore or reset? Pupil diameter transiently increases in self-chosen switches between cognitive labor and leisure in either direction

2018 ◽  
Author(s):  
Johannes Algermissen ◽  
Erik Bijleveld ◽  
Nils B. Jostmann ◽  
Rob W. Holland
Keyword(s):  
Pupil Diameter ◽  
Pupil Dilation ◽  
Alternative Possibilities ◽  
Trade Off ◽  
Trade Offs ◽  
Cognitive Work ◽  
Current Task ◽  
Related Trade ◽  
Alternative Activities

AbstractWhen people invest effort in cognitive work, they often keep an eye open for rewarding alternative activities. Previous research suggests that the norepinephrine (NE) system regulates such trade-offs between exploitation of the current task and exploration of alternative possibilities. Here we examine the possibility that the NE-system is involved in a related trade-off, i.e., the trade-off between cognitive labor and leisure. We conducted two pre-registered studies (total N = 62) in which participants freely chose to perform either a paid 2-back task (labor) vs. a non-paid task (leisure), while we tracked their pupil diameter—which is an indicator of the state of the NE system. In both studies, consistent with prior work, we found (a) increases in pupil baseline and (b) decreases in pupil dilation when participants switched from labor to leisure. Unexpectedly, we found the same pattern when participants switched from leisure back to labor. Both increases in pupil baseline and decreases in pupil dilation were short-lived. Collectively, these results are more consistent with a role of norepinephrine in reorienting attention and task switching, as suggested by network reset theory, than with a role in motivation, as suggested by adaptive gain theory.

scholarly journals Balancing selection via life-history trade-offs maintains an inversion polymorphism in a seaweed fly

2019 ◽  
Author(s):  
Claire Mérot ◽  
Violaine Llaurens ◽  
Eric Normandeau ◽  
Louis Bernatchez ◽  
Maren Wellenreuther
Keyword(s):  
Life History ◽  
Balancing Selection ◽  
Natural Populations ◽  
Inversion Polymorphism ◽  
Antagonistic Pleiotropy ◽  
Trade Off ◽  
Trade Offs ◽  
Survival And Reproduction ◽  
Coelopa Frigida

AbstractHow genetic diversity is maintained in natural populations is an evolutionary puzzle. Over time, genetic variation within species can be eroded by drift and directional selection, leading to the fixation or elimination of alleles. However, some loci show persistent variants at intermediate frequencies for long evolutionary time-scales, implicating a role of balancing selection, but studies are seldom set up to uncover the underlying processes. Here, we identify and quantify the selective pressures involved in the widespread maintenance of an inversion polymorphism in the seaweed fly Coelopa frigida, using an experimental evolution approach to estimate fitness associated with different allelic combinations. By precisely evaluating reproductive success and survival rates separately, we show that the maintenance of the polymorphism is governed by a life-history trade-off, whereby each inverted haplotype has opposed pleiotropic effects on survival and reproduction. Using numerical simulations, we confirm that this uncovered antagonism between natural and sexual selection can maintain inversion variation in natural populations of C. frigida. Moreover, our experimental data highlights that inversion-associated fitness is affected differently by sex, dominance and environmental heterogeneity. The interaction between these factors promotes polymorphism maintenance through antagonistic pleiotropy. Taken together, our findings indicate that combinations of natural and sexual selective mechanisms enable the persistence of diverse trait in nature. The joint dynamics of life history trade-offs and antagonistic pleiotropy documented here is likely to apply to other species where large phenotypic variation is controlled by structural variants.Significance statementPersistence of chromosomal rearrangements is widespread in nature and often associated with divergent life-history traits. Understanding how contrasted life-history strategies are maintained in wild populations has implications for food production, health and biodiversity in a changing environment. Using the seaweed fly Coelopa frigida, we show that a polymorphic chromosomal inversion is maintained by a trade-off between survival and reproduction, and thus provide empirical support for a role of balancing selection via antagonistic pleiotropy. This mechanism has long been overlooked because it was thought to only apply to a narrow range of ecological scenarios. These findings empirically reinforce the recent theoretical predictions that co-interacting factors (dominance, environment and sex) can lead to polymorphism maintenance by antagonistic pleiotropy and favour life-history variation.

scholarly journals Viral mutation rates: modelling the roles of within-host viral dynamics and the trade-off between replication fidelity and speed

2013 ◽  
Vol 280 (1750) ◽  
pp. 20122047 ◽  
Author(s):  
Roland R. Regoes ◽  
Steven Hamblin ◽  
Mark M. Tanaka
Keyword(s):  
Life History ◽  
Mutation Rate ◽  
High Rate ◽  
Mutation Rates ◽  
Viral Dynamics ◽  
Trade Off ◽  
Trade Offs ◽  
Very High ◽  
Host Death

Many viruses, particularly RNA viruses, mutate at a very high rate per genome per replication. One possible explanation is that high mutation rates are selected to meet the challenge of fluctuating environments, including the host immune response. Alternatively, recent studies argue that viruses evolve under a trade-off between replication speed and fidelity such that fast replication is selected, and, along with it, high mutation rates. Here, in addition to these factors, we consider the role of viral life-history properties: namely, the within-host dynamics of viruses resulting from their interaction with the host. We develop mathematical models incorporating factors occurring within and between hosts, including deleterious and advantageous mutations, host death owing to virulence and clearance of viruses by the host. Beneficial mutations confer both a within-host and a transmission advantage. First, we find that advantageous mutations have only a weak effect on the optimal genomic mutation rate. Second, viral life-history properties have a large effect on the mutation rate. Third, when the speed–fidelity trade-off is included, there can be two locally optimal mutation rates. Our analysis provides a way to consider how life-history properties combine with biochemical trade-offs to shape mutation rates.

scholarly journals Cardiotonic Steroids and the Sodium Trade Balance: New Insights into Trade-Off Mechanisms Mediated by the Na+/K+-ATPase

2018 ◽  
Vol 19 (9) ◽  
pp. 2576 ◽  
Author(s):  
Fatimah Khalaf ◽  
Prabhatchandra Dube ◽  
Amal Mohamed ◽  
Jiang Tian ◽  
Deepak Malhotra ◽  
...  
Keyword(s):  
Volume Overload ◽  
Physiological Adaptation ◽  
Ion Pump ◽  
Trade Off ◽  
Trade Offs ◽  
Target Organs ◽  
Clinical Disorders ◽  
Adaptation Processes

In 1972 Neal Bricker presented the “trade-off” hypothesis in which he detailed the role of physiological adaptation processes in mediating some of the pathophysiology associated with declines in renal function. In the late 1990’s Xie and Askari published seminal studies indicating that the Na+/K+-ATPase (NKA) was not only an ion pump, but also a signal transducer that interacts with several signaling partners. Since this discovery, numerous studies from multiple laboratories have shown that the NKA is a central player in mediating some of these long-term “trade-offs” of the physiological adaptation processes which Bricker originally proposed in the 1970’s. In fact, NKA ligands such as cardiotonic steroids (CTS), have been shown to signal through NKA, and consequently been implicated in mediating both adaptive and maladaptive responses to volume overload such as fibrosis and oxidative stress. In this review we will emphasize the role the NKA plays in this “trade-off” with respect to CTS signaling and its implication in inflammation and fibrosis in target organs including the heart, kidney, and vasculature. As inflammation and fibrosis exhibit key roles in the pathogenesis of a number of clinical disorders such as chronic kidney disease, heart failure, atherosclerosis, obesity, preeclampsia, and aging, this review will also highlight the role of newly discovered NKA signaling partners in mediating some of these conditions.

Dual Goals for Speed and Accuracy on the Same Performance Task

2012 ◽  
Vol 11 (3) ◽  
pp. 118-126 ◽  
Author(s):  
Olive Emil Wetter ◽  
Jürgen Wegge ◽  
Klaus Jonas ◽  
Klaus-Helmut Schmidt
Keyword(s):  
Memory Scanning ◽  
Performance Task ◽  
Performance Tasks ◽  
Trade Off ◽  
Test Experiment ◽  
Trade Offs ◽  
New Finding ◽  
Sternberg Paradigm ◽  
Speed Accuracy ◽  
Speed And Accuracy

In most work contexts, several performance goals coexist, and conflicts between them and trade-offs can occur. Our paper is the first to contrast a dual goal for speed and accuracy with a single goal for speed on the same task. The Sternberg paradigm (Experiment 1, n = 57) and the d2 test (Experiment 2, n = 19) were used as performance tasks. Speed measures and errors revealed in both experiments that dual as well as single goals increase performance by enhancing memory scanning. However, the single speed goal triggered a speed-accuracy trade-off, favoring speed over accuracy, whereas this was not the case with the dual goal. In difficult trials, dual goals slowed down scanning processes again so that errors could be prevented. This new finding is particularly relevant for security domains, where both aspects have to be managed simultaneously.

Sign in / Sign up

Export Citation Format

Share Document