scholarly journals On the importance of time scales when studying adaptive evolution

2018 ◽  
Author(s):  
Charles Perrier ◽  
Anne Charmantier
Keyword(s):  
Time Scales ◽  
Quantitative Traits ◽  
Field Studies ◽  
Data Series ◽  
Wild Populations ◽  
Short Term ◽  
Trait Variation ◽  
Bill Length ◽  
Term Field

AbstractLong-term field studies coupled with quantitative genomics offer a powerful means to understand the genetic bases underlying quantitative traits and their evolutionary changes. However, analyzing and interpreting the time scales at which adaptive evolution occurs is challenging. First, while evolution is predictable in the short term, with strikingly rapid phenotypic changes in data series, it remains unpredictable in the long term. Second, while the temporal dynamics of some loci with large effect on phenotypic variation and fitness have been characterized, this task can be complicated in cases of highly polygenic trait architecture implicating numerous small effect size loci, or when statistical tests are sensitive to the heterogeneity of some key characteristics of the genome, like recombination rate variations. After introducing these aforementioned challenges, we discuss a recent investigation of the genomic architecture and spatio-temporal variation in great tit bill length, which was related to the recent use of bird feeders. We discuss how this case study illustrates the importance of considering different temporal scales and evolutionary mechanisms both while analyzing trait temporal trends and when searching for and interpreting the signals of putative genomic footprints of selection. More generally this commentary discusses interesting challenges for unraveling the time scale at which adaptive traits evolve and their genomic bases.Impact summaryAn important goal in evolutionary biology is to understand how individual traits evolve, leading to fascinating variations in time and space. Long-term field studies have been crucial in trying to understand the timing, extent, and ecological determinants of such trait variation in wild populations. In this context, recent genomic tools can be used to look for the genetic bases underlying such trait variation and can provide clues on the nature and timing of their evolution. However, the analysis and the interpretation of the time scales at which evolution occurs remain challenging. First, analyzing long-term data series can be tricky; short-term changes are highly predictable whereas long-term evolution is much less predictable. A second difficult task is to study the architecture of complex quantitative traits and to decipher the timing and roles of the several genomic mechanisms involved in their evolution. This commentary introduces these challenges and discusses a recent investigation of the nature and timing of ecological and genomic factors responsible for variation in great tit bill length. Overall, we raise cautionary warnings regarding several conceptual and technical features and limitations when coupling analyses of long-term and genomic data to study trait evolution in wild populations.

scholarly journals Long-term field studies of mammals: what the short-term study cannot tell us

2017 ◽  
Vol 98 (3) ◽  
pp. 600-602 ◽  
Author(s):  
Loren D. Hayes ◽  
Carsten Schradin
Keyword(s):  
Field Studies ◽  
Short Term ◽  
Term Study ◽  
Short Term Study ◽  
Term Field

scholarly journals BrO/SO<sub>2</sub> molar ratios from scanning DOAS measurements in the NOVAC network

2013 ◽  
Vol 5 (2) ◽  
pp. 1845-1870 ◽  
Author(s):  
P. Lübcke ◽  
N. Bobrowski ◽  
S. Arellano ◽  
B. Galle ◽  
G. Garzón ◽  
...  
Keyword(s):  
Molar Ratio ◽  
Optical Absorption Spectroscopy ◽  
Short Term ◽  
Dynamic Changes ◽  
Volcanic System ◽  
Molar Ratios ◽  
Remote Sensing Technique ◽  
Field Campaigns ◽  
Term Field

Abstract. The molar ratio of BrO to SO2 is, like other halogen/sulphur ratios, a~possible precursor for dynamic changes in the shallow part of a volcanic system. While the predictive significance of the BrO/SO2 ratio has not been well constrained yet, it has the major advantage that this ratio can be readily measured using the remote-sensing technique Differential Optical Absorption Spectroscopy (DOAS) in the UV. While BrO/SO2 ratios have been measured during several short-term field campaigns this article presents an algorithm that can be used to obtain long-term time series of BrO/SO2 ratios from the scanning DOAS instruments of the Network for Observation of Volcanic and Atmospheric Change (NOVAC) or comparable networks. Parameters of the DOAS retrieval of both trace gases are given and the influence of co-adding spectra on the retrieval error will be investigated. Difficulties in the evaluation of spectroscopic data from monitoring instruments in volcanic environments and possible solutions are discussed. The new algorithm is demonstrated by evaluating data from the NOVAC scanning DOAS systems at Nevado del Ruiz, Colombia encompassing almost four years of measurements between November 2009 and end of June 2013. This dataset shows variations of the BrO/SO2 ratio several weeks prior to the eruption on 30 June 2012.

scholarly journals Analisis Indeks Harga Konsumen di Indonesia Melalui Pendekatan Kointegrasi

2019 ◽  
Vol 4 (2) ◽  
pp. 110-118
Author(s):  
Muhamad Muin ◽  
Keyword(s):  
Exchange Rate ◽  
Empirical Study ◽  
Money Supply ◽  
Price Index ◽  
Consumer Price Index ◽  
Data Series ◽  
Short Term ◽  
Monthly Data ◽  
The Relationship

This study aims to analyze the relationship between the rupiah exchange rate (RER) and the money supply (M1) on the outgrowth of the consumer price index (CPI) in Indonesia. The data used in this study are monthly data series from January 2005 to January 2019. The results of this empirical study shows that there is a relationship between RER and M1 on CPI in the long term and there is a correction in the short term balance (ECM) which is influenced by M1. All of these variables are significant at α = 5% and partly significant at α = 1%.

scholarly journals Short- and Long-Term Effects of Nonconsciously Processed Ambient Scents in a Servicescape: Findings From Two Field Experiments

2019 ◽  
Vol 22 (4) ◽  
pp. 440-455 ◽  
Author(s):  
Anna Girard ◽  
Marcel Lichters ◽  
Marko Sarstedt ◽  
Dipayan Biswas
Keyword(s):  
Large Scale ◽  
Field Experiments ◽  
Field Studies ◽  
Long Term Effects ◽  
Short Term ◽  
Railway Company ◽  
Short And Long Term ◽  
Ambient Scents ◽  
Short Term Effects

Ambient scents are being increasingly used in different service environments. While there is emerging research on the effects of scents, almost nothing is known about the long-term effects of consumers’ repeated exposure to ambient scents in a service environment as prior studies on ambient scents have been lab or field studies examining short-term effects of scent exposure only. Addressing this limitation, we examine the short- and long-term effects of ambient scents. Specifically, we present a conceptual framework for the short- and long-term effects of nonconsciously processed ambient scent in olfactory-rich servicescapes. We empirically test this framework with the help of two large-scale field experiments, conducted in collaboration with a major German railway company, in which consumers were exposed to a pleasant, nonconsciously processed scent. The first experiment demonstrates ambient scent’s positive short-term effects on consumers’ service perceptions. The second experiment—a longitudinal study conducted over a 4-month period—examines scent’s long-term effects on consumers’ reactions and demonstrates that the effects persist even when the scent has been removed from the servicescape.

scholarly journals Short-Term and Long-Term Surface Soil Moisture Memory Time Scales Are Spatially Anticorrelated at Global Scales

2019 ◽  
Vol 20 (6) ◽  
pp. 1165-1182 ◽  
Author(s):  
Kaighin A. McColl ◽  
Qing He ◽  
Hui Lu ◽  
Dara Entekhabi
Keyword(s):  
Soil Moisture ◽  
Time Scales ◽  
Time Scale ◽  
Surface Soil ◽  
Satellite Observations ◽  
Surface Soil Moisture ◽  
Short Term ◽  
Term Memory ◽  
Memory Time

Abstract Land–atmosphere feedbacks occurring on daily to weekly time scales can magnify the intensity and duration of extreme weather events, such as droughts, heat waves, and convective storms. For such feedbacks to occur, the coupled land–atmosphere system must exhibit sufficient memory of soil moisture anomalies associated with the extreme event. The soil moisture autocorrelation e-folding time scale has been used previously to estimate soil moisture memory. However, the theoretical basis for this metric (i.e., that the land water budget is reasonably approximated by a red noise process) does not apply at finer spatial and temporal resolutions relevant to modern satellite observations and models. In this study, two memory time scale metrics are introduced that are relevant to modern satellite observations and models: the “long-term memory” τL and the “short-term memory” τS. Short- and long-term surface soil moisture (SSM) memory time scales are spatially anticorrelated at global scales in both a model and satellite observations, suggesting hot spots of land–atmosphere coupling will be located in different regions, depending on the time scale of the feedback. Furthermore, the spatial anticorrelation between τS and τL demonstrates the importance of characterizing these memory time scales separately, rather than mixing them as in previous studies.

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