Landscape‐Level Effects on Developmental Instability: Fluctuating Asymmetry across the Range of Honey Locust, Gleditsia triacanthos (Fabaceae)

2004 ◽  
Vol 165 (5) ◽  
pp. 795-803 ◽  
Author(s):  
Helen T. Murphy ◽  
Jon Lovett‐Doust
Symmetry ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 9
Author(s):  
John H. Graham

Best practices in studies of developmental instability, as measured by fluctuating asymmetry, have developed over the past 60 years. Unfortunately, they are haphazardly applied in many of the papers submitted for review. Most often, research designs suffer from lack of randomization, inadequate replication, poor attention to size scaling, lack of attention to measurement error, and unrecognized mixtures of additive and multiplicative errors. Here, I summarize a set of best practices, especially in studies that examine the effects of environmental stress on fluctuating asymmetry.


Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1204
Author(s):  
John H. Graham

Phenotypic variation arises from genetic and environmental variation, as well as random aspects of development. The genetic (nature) and environmental (nurture) components of this variation have been appreciated since at least 1900. The random developmental component (noise) has taken longer for quantitative geneticists to appreciate. Here, I sketch the historical development of the concepts of random developmental noise and developmental instability, and its quantification via fluctuating asymmetry. The unsung pioneers in this story are Hugo DeVries (fluctuating variation, 1909), C. H. Danforth (random variation between monozygotic twins, 1919), and Sewall Wright (random developmental variation in piebald guinea pigs, 1920). The first pioneering study of fluctuating asymmetry, by Sumner and Huestis in 1921, is seldom mentioned, possibly because it failed to connect the observed random asymmetry with random developmental variation. This early work was then synthesized by Boris Astaurov in 1930 and Wilhelm Ludwig in 1932, and then popularized by Drosophila geneticists beginning with Kenneth Mather in 1953. Population phenogeneticists are still trying to understand the origins and behavior of random developmental variation. Some of the developmental noise represents true stochastic behavior of molecules and cells, while some represents deterministic chaos, nonlinear feedback, and symmetry breaking.


2015 ◽  
Vol 18 ◽  
pp. 266-274 ◽  
Author(s):  
Chuan-Rui Zhang ◽  
Amila A. Dissanayake ◽  
Muraleedharan G. Nair

2019 ◽  
Vol 81 (3) ◽  
pp. 146-150
Author(s):  
Marcel Robischon

Object-based learning is an approach that aims to foster observational skills and sensory awareness. Paradoxical plant objects that do not lend themselves to all-too-easy explanations and interpretations can be used to practice the search for ecological explanations and the formation of evolutionary hypotheses. They can be the basis of particularly fruitful and rewarding learning experiences. Gleditsia triacanthos, the honey locust, is a commonly planted ornamental tree. It exhibits striking structures of defense against – and fruit that point to a mutualism with – large animals. These structures, possibly developed in coevolution with Pleistocene faunas, invite a discussion of the complex, neither fully antagonistic nor fully mutualistic, relationships between plants and animals.


Biologia ◽  
2010 ◽  
Vol 65 (1) ◽  
Author(s):  
Mátyás Bellaagh ◽  
Eszter Lazányi ◽  
Zoltán Korsós

AbstractThe Fluctuating Asymmetry (FA) is a special type of asymmetry in the populations of bilaterally symmetrical creatures. The FA gives us numerical data on the developmental instability of the populations and refers to potential genetical and environmental stressors affecting the populations. Here we give the first data on the FA of the protected Caspian whipsnake (Hierophis caspius) from Hungary. The FA indices of the biggest population from Villány Mts were compared to the FA indices of two differently stressed Dice snake (Natrix tessellata) populations [stressed (Mád) and seminatural (Lake Balaton)]. Based on the values of the multiple and the simple indices derived from sublabial scales, we can say that the status quo of the highly protected Caspian whipsnake population does not represent significant deviation from the near-natural dice snake population from the Lake Balaton.


2007 ◽  
Vol 97 (1) ◽  
pp. 61-67 ◽  
Author(s):  
R. Olivares-Donoso ◽  
A.J. Troncoso ◽  
D.H. Tapia ◽  
D. Aguilera-Olivares ◽  
H.M. Niemeyer

AbstractTransgenerational maternal effects on performance (rm) after host transfer were evaluated in the generalist aphid Myzus persicae s.s., and in its subspecies specialized on tobacco, M. persicae nicotianae Blackman. We tested whether the performance of these taxa, when reared separately on optimal and suboptimal hosts (as sources of different maternal background) and then transferred to optimal hosts, experienced variations along four successive generations. Additionally, to compare the tolerance of both taxa to stress following host transfers, developmental instability (fluctuating asymmetry and body abnormalities) along the four generations was assessed. Taxon, rearing host, and generation affected the performance after host transfer. In the generalist, there was a significant improvement of rm along generations when transferred from suboptimal to optimal host and a significant decrease when transferred from optimal to optimal host; in the specialist, no increase or decrease occurred in any host transfer treatment. Transfer from suboptimal to optimal hosts caused higher losses of remaining replicates along generations than transfers from optimal to optimal hosts, and the specialist showed higher losses than the generalist. The only significant effect detected in comparisons involving fluctuating asymmetry values was that of taxon on length of siphunculi. Frequency of body abnormalities was not affected by treatments. Collectively, these results show a transgenerational weakening of maternal effects in the generalist but not in the specialist aphid, and suggest that rearing the latter in a suboptimal host causes not easily reversible changes that further give rise to constraints in performance.


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