scholarly journals Biogeography of shell morphology in over‐exploited shellfish reveals adaptive trade‐offs on human‐inhabited islands and incipient selectively driven lineage bifurcation

2020 ◽  
Vol 47 (7) ◽  
pp. 1494-1509
Author(s):  
Ashley M. Hamilton ◽  
Jason D. Selwyn ◽  
Rebecca M. Hamner ◽  
Hokuala K. Johnson ◽  
Tia Brown ◽  
...  
Keyword(s):  
Shell Morphology ◽  
Trade Offs

Ecophenotypy, temporal and spatial fidelity, functional morphology, and physiological trade-offs among intertidal bivalves

Paleobiology ◽  
2018 ◽  
Vol 44 (3) ◽  
pp. 530-545
Author(s):  
John Warren Huntley ◽  
James D. Schiffbauer ◽  
Teresa D. Avila ◽  
Jesse S. Broce
Keyword(s):  
High Energy ◽  
Shell Morphology ◽  
Time Averaging ◽  
Spatial Averaging ◽  
Substrate Type ◽  
Fine Grained ◽  
Trade Offs ◽  
Death Assemblages ◽  
Temporal And Spatial ◽  
Type Water

AbstractEcophenotypic variation in populations is driven by differences in environmental variables. In marine environments, ecophenotypic variation may be caused by differences in hydrodynamic conditions, substrate type, water depth, temperature, salinity, oxygen concentration, and habitat heterogeneity, among others. Instances of ecophenotypic variation in modern and fossil settings are common, but little is known about the influences of time averaging and spatial averaging on their preservation. Here we examine the shell morphology of two adjacent populations, both live collected and death assemblages, of the infaunal, suspension-feeding, intertidal bivalve Leukoma staminea from the well-studied Argyle Creek and Argyle Lagoon locations on San Juan Island, Washington. Individuals in the low-energy lagoon are free to burrow in the fine-grained substrate, while clams in the high-energy creek are precluded from burrowing in the rocky channel. Our results demonstrate variation in size and shape between the adjacent habitats. Lagoon clams are larger, more disk-shaped, and have relatively larger siphons than their creek counterparts, which are smaller, more spherical in shape, and have a relatively shallower pallial sinus. This ecophenotypy is preserved among death assemblages, although with generally greater variation due to time averaging and shell transport. Our interpretation is that ecophenotypic variation, in this case, is induced by differing hydrodynamic regimes and substrate types, cumulatively resulting in physiological trade-offs diverting resources from feeding and respiration to stability and shell strength, all of which have the potential to be preserved in the fossil record.

Novel players fine-tune plant trade-offs

2015 ◽  
Vol 58 ◽  
pp. 83-100 ◽  
Author(s):  
Selena Gimenez-Ibanez ◽  
Marta Boter ◽  
Roberto Solano
Keyword(s):  
Ubiquitin Ligase ◽  
Feedback Loop ◽  
Molecular Level ◽  
26S Proteasome ◽  
Signalling Molecules ◽  
Transcriptional Reprogramming ◽  
Trade Offs ◽  
Jaz Proteins ◽  
Regulatory Feedback Loop ◽  
Fine Tune

Jasmonates (JAs) are essential signalling molecules that co-ordinate the plant response to biotic and abiotic challenges, as well as co-ordinating several developmental processes. Huge progress has been made over the last decade in understanding the components and mechanisms that govern JA perception and signalling. The bioactive form of the hormone, (+)-7-iso-jasmonyl-l-isoleucine (JA-Ile), is perceived by the COI1–JAZ co-receptor complex. JASMONATE ZIM DOMAIN (JAZ) proteins also act as direct repressors of transcriptional activators such as MYC2. In the emerging picture of JA-Ile perception and signalling, COI1 operates as an E3 ubiquitin ligase that upon binding of JA-Ile targets JAZ repressors for degradation by the 26S proteasome, thereby derepressing transcription factors such as MYC2, which in turn activate JA-Ile-dependent transcriptional reprogramming. It is noteworthy that MYCs and different spliced variants of the JAZ proteins are involved in a negative regulatory feedback loop, which suggests a model that rapidly turns the transcriptional JA-Ile responses on and off and thereby avoids a detrimental overactivation of the pathway. This chapter highlights the most recent advances in our understanding of JA-Ile signalling, focusing on the latest repertoire of new targets of JAZ proteins to control different sets of JA-Ile-mediated responses, novel mechanisms of negative regulation of JA-Ile signalling, and hormonal cross-talk at the molecular level that ultimately determines plant adaptability and survival.

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.

Traits and trade-offs are insufficient for evolutionary personality psychology.

2007 ◽  
Vol 62 (9) ◽  
pp. 1073-1074 ◽  
Author(s):  
Kennon M. Sheldon ◽  
Melanie S. Sheldon ◽  
Charles P. Nichols
Keyword(s):  
Personality Psychology ◽  
Trade Offs

Trade-offs Between Economic and Social Goals

2007 ◽  
Author(s):  
Poonam Arora ◽  
David H. Krantz ◽  
David Hardisty ◽  
Nicole Peterson ◽  
Kavita Reddy
Keyword(s):  
Social Goals ◽  
Trade Offs

Trade-offs for equitable climate policy assessed

Nature ◽  
2020 ◽  
Vol 588 (7837) ◽  
pp. 225-226
Author(s):  
Wei Peng
Keyword(s):  
Climate Policy ◽  
Trade Offs

A Political Economy Model of a Research University

2009 ◽  
pp. 132-143
Author(s):  
K. Sonin ◽  
I. Khovanskaya
Keyword(s):  
Organizational Structure ◽  
Information Structure ◽  
Research University ◽  
Hiring Decisions ◽  
Voting Rules ◽  
Economy Model ◽  
Trade Offs ◽  
Political Economic ◽  
Optimal Incentives

Hiring decisions are typically made by committees members of which have different capacity to estimate the quality of candidates. Organizational structure and voting rules in the committees determine the incentives and strategies of applicants; thus, construction of a modern university requires a political structure that provides committee members and applicants with optimal incentives. The existing political-economic model of informative voting typically lacks any degree of variance in the organizational structure, while political-economic models of organization typically assume a parsimonious information structure. In this paper, we propose a simple framework to analyze trade-offs in optimal subdivision of universities into departments and subdepartments, and allocation of political power.

Experimentally increased costs of parental care are shunted to offspring in species with extended care

2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser
Keyword(s):  
Life History ◽  
Parental Care ◽  
Total Duration ◽  
Bird Species ◽  
Life History Strategy ◽  
Experimental Treatment ◽  
Cost Of Care ◽  
Adult Survival ◽  
Supporting Evidence ◽  
Trade Offs

Biparental care systems are a valuable model to examine conflict, cooperation, and coordination between unrelated individuals, as the product of the interactions between the parents influences the fitness of both individuals. A common experimental technique for testing coordinated responses to changes in the costs of parental care is to temporarily handicap one parent, inducing a higher cost of providing care. However, dissimilarity in experimental designs of these studies has hindered interspecific comparisons of the patterns of cost distribution between parents and offspring. Here we apply a comparative experimental approach by handicapping a parent at nests of five bird species using the same experimental treatment. In some species, a decrease in care by a handicapped parent was compensated by its partner, while in others the increased costs of care were shunted to the offspring. Parental responses to an increased cost of care primarily depended on the total duration of care that offspring require. However, life history pace (i.e., adult survival and fecundity) did not influence parental decisions when faced with a higher cost of caring. Our study highlights that a greater attention to intergenerational trade-offs is warranted, particularly in species with a large burden of parental care. Moreover, we demonstrate that parental care decisions may be weighed more against physiological workload constraints than against future prospects of reproduction, supporting evidence that avian species may devote comparable amounts of energy into survival, regardless of life history strategy.

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