scholarly journals Neurogenetics of nictation, a dispersal strategy in nematodes

2020 ◽  
pp. 1-8 ◽  
Author(s):  
Heeseung Yang ◽  
Bo Yun Lee ◽  
Hyunsoo Yim ◽  
Junho Lee
Keyword(s):  
Dispersal Strategy

scholarly journals The effect of pollen source on seed traits and dispersability in the heterocarpic annual Crepis sancta

2020 ◽  
Author(s):  
Efrat Dener ◽  
Hagai Shemesh ◽  
Itamar Giladi
Keyword(s):  
Reproductive Success ◽  
Reproductive Output ◽  
Seed Traits ◽  
Dispersal Strategy ◽  
Physiological Constraints ◽  
Dispersal Traits ◽  
Distant Neighbor ◽  
The Common ◽  
Nonsignificant Effect ◽  
Crepis Sancta

Abstract Aims The evolution and expression of dispersal-related traits are intertwined with those of other life-history functions and are manifested within various physiological constraints. Such a relationship is predicted between inbreeding levels and dispersability, which may be anatomically and ontogenetically linked so that the selection pressures on one may affect the other. While both the effect of inbreeding on reproductive success and on dispersal strategies received much attention, only a few studies considered both simultaneously. Furthermore, such studies often rely on two dichotomic representations of breeding and dispersal: using selfing vs. outcrossing as a representation of breeding level, and dispersal ratio as the sole representation of dispersal strategy. Methods Here we used pollination experiments in the heterocarpic Crepis sancta (Asteraceae) to expand in two different manners on the common practice of using dichotomic representations of breeding and dispersal. First, we used pollination treatments that represent a continuum from selfing through pollination by kin to pollination by a distant neighbor. Second, we measured a whole set of continuous morphological and dispersal-related traits, in addition to measurements of reproductive success and dispersal ratio. Important findings The proportion of developed capitula and the number of both dispersed and non-dispersed achenes were significantly lower in the self-pollination treatment in comparison to the out-crossed treatments. The effect of pollen sources on dispersal ratio was not statistically significant, though self-pollinated plants rarely produced non-dispersing seeds. Achene’s biomass increased with distance between parent plants, but pappus width did not, leading to a nonsignificant effect of pollination on falling velocity. Overall, pollen source affected mainly traits that were associated with reproductive output, but it had no clear effect on predominately dispersal-related traits. Such differences in the response of reproduction and dispersal traits to variation in pollen source suggest that dispersal-related selection is probably weak and/or masked by other forces.

scholarly journals Fruit-eating fishes of Banara arguta (Salicaceae) in the Miranda River floodplain, Pantanal wetland

2011 ◽  
Vol 11 (4) ◽  
pp. 373-376 ◽  
Author(s):  
Raul Costa-Pereira ◽  
Francisco Severo-Neto ◽  
Tamires Soares Yule ◽  
Ana Paula Tinti Pereira
Keyword(s):  
Seed Dispersal ◽  
Fish Assemblage ◽  
Scientific Literature ◽  
Ecological Studies ◽  
Dispersal Strategy ◽  
Ecological Consequences ◽  
River Floodplain ◽  
Seed Dispersers ◽  
Pantanal Wetland

The role of fish as frugivorous and its ecological consequences are often neglected in ecological studies. However, the importance of the interaction between fish and plants is gaining force in scientific literature, and fish has been considered effective seed dispersers. The fruit-eating fish assemblage of Banara arguta (Salicaceae) was evaluated in Southern Pantanal wetlands. Nine species were reported consuming fruits, with different strategies to capture them. The distribution of B. arguta associated with the Pantanal floodplain and the presence of several species of fruit-eating fish, suggest that ichthyochory can be an important seed dispersal strategy to B. arguta.

The evolution of an ‘intelligent’ dispersal strategy: biased, correlated random walks in patchy landscapes

Oikos ◽  
2009 ◽  
Vol 118 (2) ◽  
pp. 309-319 ◽  
Author(s):  
Kamil A. Barton ◽  
Ben L. Phillips ◽  
Juan M. Morales ◽  
Justin M. J. Travis
Keyword(s):  
Random Walks ◽  
Dispersal Strategy ◽  
Correlated Random Walks

scholarly journals III-3. Oceanic dispersal strategy of larval amphidromous gobies

2015 ◽  
Vol 81 (3) ◽  
pp. 482-482
Author(s):  
MIDORI IIDA ◽  
MASASHI KONDO ◽  
KEN MAEDA ◽  
KATSUNORI TACHIHARA
Keyword(s):  
Dispersal Strategy

scholarly journals Evolution of Natal Dispersal in Spatially Heterogenous Environments

2016 ◽  
Author(s):  
Robert Stephen Cantrell ◽  
Chris Cosner ◽  
Yuan Lou ◽  
Sebastian J. Schreiber
Keyword(s):  
Growth Rates ◽  
Continuous Time ◽  
Ideal Free Distribution ◽  
Natal Dispersal ◽  
Breeding Dispersal ◽  
Dispersal Strategy ◽  
Free Distribution ◽  
Per Capita ◽  
Source Sink ◽  
Ideal Free

AbstractUnderstanding the evolution of dispersal is an important issue in evolutionary ecology. For continuous time models in which individuals disperse throughout their lifetime, it has been shown that a balanced dispersal strategy, which results in an ideal free distribution, is evolutionary stable in spatially varying but temporally constant environments. Many species, however, primarily disperse prior to reproduction (natal dispersal) and less commonly between reproductive events (breeding dispersal). These species include territorial species such as birds and reef fish, and sessile species such as plants, and mollusks. As demographic and dispersal terms combine in a multiplicative way for models of natal dispersal, rather than the additive way for the previously studied models, we develop new mathematical methods to study the evolution of natal dispersal for continuous-time and discrete-time models. A fundamental ecological dichotomy is identified for the non-trivial equilibrium of these models: (i) the per-capita growth rates for individuals in all patches are equal to zero, or (ii) individuals in some patches experience negative per-capita growth rates, while individuals in other patches experience positive per-capita growth rates. The first possibility corresponds to an ideal-free distribution, while the second possibility corresponds to a “source-sink” spatial structure. We prove that populations with a dispersal strategy leading to an ideal-free distribution displace populations with dispersal strategy leading to a source-sink spatial structure. When there are patches which can not sustain a population, ideal-free strategies can be achieved by sedentary populations, and we show that these populations can displace populations with any irreducible dispersal strategy. Collectively, these results support that evolution selects for natal or breeding dispersal strategies which lead to ideal-free distributions in spatially heterogenous, but temporally homogenous, environments.

scholarly journals Seed dispersal as a search strategy: dynamic and fragmented landscapes select for multi-scale movement strategies in plants

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jelle Treep ◽  
Monique de Jager ◽  
Frederic Bartumeus ◽  
Merel B. Soons
Keyword(s):  
Seed Dispersal ◽  
Plant Species ◽  
Suitable Habitat ◽  
Dispersal Strategy ◽  
Plant Dispersal ◽  
Multi Scale ◽  
Reference Framework ◽  
Trade Offs ◽  
Movement Strategies ◽  
Wide Range

Abstract Background Plant dispersal is a critical factor driving ecological responses to global changes. Knowledge on the mechanisms of dispersal is rapidly advancing, but selective pressures responsible for the evolution of dispersal strategies remain elusive. Recent advances in animal movement ecology identified general strategies that may optimize efficiency in animal searches for food or habitat. Here we explore the potential for evolution of similar general movement strategies for plants. Methods We propose that seed dispersal in plants can be viewed as a strategic search for suitable habitat, where the probability of finding such locations has been optimized through evolution of appropriate dispersal kernels. Using model simulations, we demonstrate how dispersal strategies can optimize key dispersal trade-offs between finding habitat, avoiding kin competition, and colonizing new patches. These trade-offs depend strongly on the landscape, resulting in a tight link between optimal dispersal strategy and spatiotemporal habitat distribution. Results Our findings reveal that multi-scale seed dispersal strategies that combine a broad range of dispersal scales, including Lévy-like dispersal, are optimal across a wide range of dynamic and patchy landscapes. At the extremes, static and patchy landscapes select for dispersal strategies dominated by short distances, while uniform and highly unpredictable landscapes both select for dispersal strategies dominated by long distances. Conclusions By viewing plant seed dispersal as a strategic search for suitable habitat, we provide a reference framework for the analysis of plant dispersal data. Consideration of the entire dispersal kernel, including distances across the full range of scales, is key. This reference framework helps identify plant species’ dispersal strategies, the evolutionary forces determining these strategies and their ecological consequences, such as a potential mismatch between plant dispersal strategy and altered spatiotemporal habitat dynamics due to land use change. Our perspective opens up directions for future studies, including exploration of composite search behaviour and ‘informed searches’ in plant species with directed dispersal.

scholarly journals Are stress responses to geomagnetic storms mediated by the cryptochrome compass system?

2012 ◽  
Vol 279 (1736) ◽  
pp. 2081-2090 ◽  
Author(s):  
James Close
Keyword(s):  
Stress Responses ◽  
Geomagnetic Field ◽  
Conceptual Models ◽  
Scientific Literature ◽  
Geomagnetic Storms ◽  
Molecular System ◽  
Circadian Pacemaker ◽  
Dispersal Strategy ◽  
Established Role ◽  
Compass System

A controversial body of literature demonstrates associations of geomagnetic storms (GMS) with numerous cardiovascular, psychiatric and behavioural outcomes. Various melatonin hypotheses of GMS have suggested that temporal variation in the geomagnetic field (GMF) may be acting as an additional zeitgeber (a temporal synchronizer) for circadian rhythms, with GMS somehow interfering with the hypothesized system. The cryptochrome genes are known primarily as key components of the circadian pacemaker, ultimately involved in controlling the expression of the hormone melatonin. Cryptochrome is identified as a clear candidate for mediating the effect of GMS on humans, demonstrating the prior existence of several crucial pieces of evidence. A distinct scientific literature demonstrates the widespread use of geomagnetic information for navigation across a range of taxa. One mechanism of magnetoreception is thought to involve a light-dependent retinal molecular system mediated by cryptochrome, acting in a distinct functionality to its established role as a circadian oscillator. There is evidence suggesting that such a magnetosense—or at least the vestiges of it—may exist in humans. This paper argues that cryptochrome is not acting as secondary geomagnetic zeitgeber to influence melatonin synthesis. Instead, it is hypothesized that the cryptochrome compass system is mediating stress responses more broadly across the hypothalamic–pituitary–adrenal (HPA) axis (including alterations to circadian behaviour) in response to changes in the GMF. Two conceptual models are outlined for the existence of such responses—the first as a generalized migrational/dispersal strategy, the second as a stress response to unexpected signals to the magnetosense. It is therefore proposed that GMS lead to disorientation of hormonal systems in animals and humans, thus explaining the effects of GMS on human health and behaviour.

scholarly journals A symbiont's dispersal strategy: condition-dependent dispersal underlies predictable variation in direct transmission among hosts

2015 ◽  
Vol 282 (1819) ◽  
pp. 20152081 ◽  
Author(s):  
James Skelton ◽  
Robert P. Creed ◽  
Bryan L. Brown
Keyword(s):  
Transmission Rate ◽  
Horizontal Transmission ◽  
Host Size ◽  
Dispersal Strategy ◽  
Contact Rates ◽  
Symbiont Transmission ◽  
Strategy Condition ◽  
Living Organisms ◽  
Host Infection ◽  
Better Than

Direct horizontal transmission of pathogenic and mutualistic symbionts has profound consequences for host and symbiont fitness alike. While the importance of contact rates for transmission is widely recognized, the processes that underlie variation in transmission during contact are rarely considered. Here, we took a symbiont's perspective of transmission as a form of dispersal and adopted the concept of condition-dependent dispersal strategies from the study of free-living organisms to understand and predict variation in transmission in the cleaning symbiosis between crayfish and ectosymbiotic branchiobdellidan worms. Field study showed that symbiont reproductive success was correlated with host size and competition among worms for microhabitats. Laboratory experiments demonstrated high variability in transmission among host contacts. Moreover, symbionts were more likely to disperse when host size and competition for microhabitat created a fitness environment below a discrete minimum threshold. A predictive model based on a condition-dependent symbiont dispersal strategy correctly predicted transmission in 95% of experimental host encounters and the exact magnitude of transmission in 67%, both significantly better than predictions that assumed a fixed transmission rate. Our work provides a dispersal-based understanding of symbiont transmission and suggests adaptive symbiont dispersal strategies can explain variation in transmission dynamics and complex patterns of host infection.

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