Limits...
Modelling developmental instability as the joint action of noise and stability: a Bayesian approach.

Van Dongen S, Lens L - BMC Evol. Biol. (2002)

Bottom Line: However, the recent literature does not support an ubiquitous relationship.More research is urgently needed to get better insights in the developmental mechanisms of noise and stability.In spite of the fact that the model is likely to represent an oversimplification of reality, the accumulation of new insights could be incorporated in the Bayesian statistical approach to obtain more reliable estimation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Global Biometrics and Reporting Janssen Pharmaceutica Beerse, Belgium. svdongen@janbe.jnj.com

ABSTRACT

Background: Fluctuating asymmetry is assumed to measure individual and population level developmental stability. The latter may in turn show an association with stress, which can be observed through asymmetry-stress correlations. However, the recent literature does not support an ubiquitous relationship. Very little is known why some studies show relatively strong associations while others completely fail to find such a correlation. We propose a new Bayesian statistical framework to examine these associations

Results: We are considering developmental stability - i.e. the individual buffering capacity - as the biologically relevant trait and show that (i) little variation in developmental stability can explain observed variation in fluctuating asymmetry when the distribution of developmental stability is highly skewed, and (ii) that a previously developed tool (i.e. the hypothetical repeatability of fluctuating asymmetry) contains only limited information about variation in developmental stability, which stands in sharp contrast to the earlier established close association between the repeatability and developmental instability.

Conclusion: We provide tools to generate valuable information about the distribution of between-individual variation in developmental stability. A simple linear transformation of a previous model lead to completely different conclusions. Thus, theoretical modelling of asymmetry and stability appears to be very sensitive to the scale of inference. More research is urgently needed to get better insights in the developmental mechanisms of noise and stability. In spite of the fact that the model is likely to represent an oversimplification of reality, the accumulation of new insights could be incorporated in the Bayesian statistical approach to obtain more reliable estimation.

Show MeSH

Related in: MedlinePlus

Relationship between the coefficient of variation (CV) of both DS and instability and the hypothetical repeatability (R) Mean values and their standard deviation were obtained for a range of distributions of variation in DS. Details are provided in Figure 1 and Table 1. The theoretical upper limit of R equals 0.637 and is indicated by a horizontal line
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC117071&req=5

Figure 2: Relationship between the coefficient of variation (CV) of both DS and instability and the hypothetical repeatability (R) Mean values and their standard deviation were obtained for a range of distributions of variation in DS. Details are provided in Figure 1 and Table 1. The theoretical upper limit of R equals 0.637 and is indicated by a horizontal line

Mentions: The beta-distributions applied to model variation in DS generated a broad range of CV values for both DS and DI and of values of R (Table 1). In agreement with earlier results [13,15], R was closely and positively associated with the CV of DI (Fig. 2). Values larger than 100% were required to obtain relative large values of R (>0.4). However, when examining the relationship at the level of DS, the association was negative (Fig. 2) indicating that only small amounts of variation in DS were required to obtain large values of R. For example, the largest value of R was obtained with a left skewed distribution of DS with a values of CV equal to only 17% (Table 1), hereby lying well within the range of morphological and fitness traits [13].


Modelling developmental instability as the joint action of noise and stability: a Bayesian approach.

Van Dongen S, Lens L - BMC Evol. Biol. (2002)

Relationship between the coefficient of variation (CV) of both DS and instability and the hypothetical repeatability (R) Mean values and their standard deviation were obtained for a range of distributions of variation in DS. Details are provided in Figure 1 and Table 1. The theoretical upper limit of R equals 0.637 and is indicated by a horizontal line
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC117071&req=5

Figure 2: Relationship between the coefficient of variation (CV) of both DS and instability and the hypothetical repeatability (R) Mean values and their standard deviation were obtained for a range of distributions of variation in DS. Details are provided in Figure 1 and Table 1. The theoretical upper limit of R equals 0.637 and is indicated by a horizontal line
Mentions: The beta-distributions applied to model variation in DS generated a broad range of CV values for both DS and DI and of values of R (Table 1). In agreement with earlier results [13,15], R was closely and positively associated with the CV of DI (Fig. 2). Values larger than 100% were required to obtain relative large values of R (>0.4). However, when examining the relationship at the level of DS, the association was negative (Fig. 2) indicating that only small amounts of variation in DS were required to obtain large values of R. For example, the largest value of R was obtained with a left skewed distribution of DS with a values of CV equal to only 17% (Table 1), hereby lying well within the range of morphological and fitness traits [13].

Bottom Line: However, the recent literature does not support an ubiquitous relationship.More research is urgently needed to get better insights in the developmental mechanisms of noise and stability.In spite of the fact that the model is likely to represent an oversimplification of reality, the accumulation of new insights could be incorporated in the Bayesian statistical approach to obtain more reliable estimation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Global Biometrics and Reporting Janssen Pharmaceutica Beerse, Belgium. svdongen@janbe.jnj.com

ABSTRACT

Background: Fluctuating asymmetry is assumed to measure individual and population level developmental stability. The latter may in turn show an association with stress, which can be observed through asymmetry-stress correlations. However, the recent literature does not support an ubiquitous relationship. Very little is known why some studies show relatively strong associations while others completely fail to find such a correlation. We propose a new Bayesian statistical framework to examine these associations

Results: We are considering developmental stability - i.e. the individual buffering capacity - as the biologically relevant trait and show that (i) little variation in developmental stability can explain observed variation in fluctuating asymmetry when the distribution of developmental stability is highly skewed, and (ii) that a previously developed tool (i.e. the hypothetical repeatability of fluctuating asymmetry) contains only limited information about variation in developmental stability, which stands in sharp contrast to the earlier established close association between the repeatability and developmental instability.

Conclusion: We provide tools to generate valuable information about the distribution of between-individual variation in developmental stability. A simple linear transformation of a previous model lead to completely different conclusions. Thus, theoretical modelling of asymmetry and stability appears to be very sensitive to the scale of inference. More research is urgently needed to get better insights in the developmental mechanisms of noise and stability. In spite of the fact that the model is likely to represent an oversimplification of reality, the accumulation of new insights could be incorporated in the Bayesian statistical approach to obtain more reliable estimation.

Show MeSH
Related in: MedlinePlus