1,190 research outputs found
A case for environmental statistics of early life effects
This is the author accepted manuscript. The final version is available from The Royal Society via the DOI in this record.There is enduring debate over the question which early life effects are adaptive and which ones
are not. Mathematical modelling shows that early life effects can be adaptive in environments
that have particular statistical properties, such as reliable cues to current conditions and high
autocorrelation of environmental states. However, few empirical studies have measured these
properties, leading to an impasse. Progress, therefore, depends on research that quantifies cue
reliability and autocorrelation of environmental parameters in real environments. These
statistics may be different for social and non-social aspects of the environment. In this paper, we
summarise evolutionary models of early life effects. Then we discuss empirical data on
environmental statistics from a range of disciplines. We highlight cases where data on
environmental statistics have been used to test competing explanations of early-life effects. We
conclude by providing guidelines for new data collection and reflections on future directions.Leverhulme Trus
Environmental transmission of a personality trait: foster parent exploration behaviour predicts offspring exploration behaviour in zebra finches
Consistent behavioural differences among individuals are common in many species and can have important effects on offspring fitness. To understand such ‘personality’ variation, it is important to determine the mode ofinheritance, but this has been quantified for only a few species. Here, we report results from a breeding experiment in captive zebra finches, Taeniopygia guttata, in which we cross-fostered offspring to disentangle the importance of genetic and nongenetic transmission of behaviour. Genetic and foster-parents’ exploratory type was measured in a novel environment pre-breeding and offspring exploratory type was assessed at adulthood. Offspring exploratory type was predicted by the exploratory behaviour of the foster but not the genetic parents, whereas offspring sizewas predicted by genetic but not foster-parents’ size. Other aspects of the social environment, such as rearing regime (uni- versus biparental), hatching position, brood size or an individual’s sex did not influence offspring exploration. Our results therefore indicate that non-genetic transmission of behaviour can play an important role in shaping animal personality variation
Significant Contribution of Large Particles to Optical Backscattering in the Open Ocean
The light scattering properties of oceanic particles have been suggested as an alternative index of phytoplankton biomass than chlorophyll-a concentration (chl-a), with the benefit of being less sensitive to physiological forcings (e.g., light and nutrients) that alter the intracellular pigment concentrations. The drawback of particulate scattering is that it is not unique to phytoplankton. Nevertheless, field studies have demonstrated that, to first order, the particulate beam-attenuation coefficient (c(p)) can track phytoplankton biomass. The relationship between c(p) and the particulate backscattering coefficient (b(bp)), a property retrievable from space, has not been fully evaluated, largely due to a lack of open-ocean field observations. Here, we present extensive data on inherent optical properties from the Equatorial Pacific surface waters and demonstrate a remarkable coherence in b(bp) and c(p). Coincident measurements of particle size distributions (PSDs) and optical properties of size-fractionated samples indicate that this covariance is due to both the conserved nature of the PSD and a greater contribution of phytoplankton-sized particles to b(bp) than theoretically predicted. These findings suggest that satellite-derived b(bp)could provide similar information on phytoplankton biomass in the open ocean as c(p)
Intermittency of glassy relaxation and the emergence of a non-equilibrium spontaneous measure in the aging regime
We consider heat exchange processes between non-equilibrium aging systems (in
their activated regime) and the thermal bath in contact. We discuss a scenario
where two different heat exchange processes concur in the overall heat
dissipation: a stimulated fast process determined by the temperature of the
bath and a spontaneous intermittent process determined by the fact that the
system has been prepared in a non-equilibrium state. The latter is described by
a probability distribution function (PDF) that has an exponential tail of width
given by a parameter , and satisfies a fluctuation theorem (FT)
governed by that parameter. The value of is proportional to the
so-called effective temperature, thereby providing a practical way to
experimentally measure it by analyzing the PDF of intermittent events.Comment: Latex file, 8 pages + 5 postscript figure
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