scholarly journals Population density and developmental stress in the Neolithic: A diachronic study of dental fluctuating asymmetry at Çatalhöyük (Turkey, 7,100-5,950 BC)

2018 ◽  
Vol 167 (4) ◽  
pp. 737-749 ◽  
Author(s):  
Marco Milella ◽  
Barbara J. Betz ◽  
Christopher J. Knüsel ◽  
Clark Spencer Larsen ◽  
Irene Dori
Keyword(s):  
Population Density ◽  
Fluctuating Asymmetry ◽  
Developmental Stress ◽  
Diachronic Study

scholarly journals Breaking Symmetry: Fluctuating Asymmetry and Geometric Morphometrics as Tools for Evaluating Developmental Instability under Diverse Agroecosystems

Symmetry ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1789 ◽  
Author(s):  
Hugo A. Benítez ◽  
Darija Lemic ◽  
Amado Villalobos-Leiva ◽  
Renata Bažok ◽  
Rodrigo Órdenes-Claveria ◽  
...  
Keyword(s):  
Population Density ◽  
Geometric Morphometrics ◽  
Fluctuating Asymmetry ◽  
Developmental Differences ◽  
Environmental Stressors ◽  
Chemical Pollution ◽  
Developmental Stress ◽  
Bilateral Asymmetry ◽  
Selection Pressures ◽  
Breaking Symmetry

Fluctuating asymmetry (FA), in contrast with other asymmetries, is the bilateral asymmetry that represents small, random developmental differences between right and left sides. After nearly a century of using traditional morphometrics in the estimation of FA, geometric morphometrics (GM) now provides new insights into the use of FA as a tool, especially for assessing environmental and developmental stress. Thus, it will be possible to assess adaptation to various environmental stressors as particular triggers for unavoidable selection pressures. In this review, we describe measures of FA that use geometric morphometrics, and we include a flow chart of the methodology. We also describe how this combination (GM + FA) has been tested in several agroecosystems. Nutritional stress, temperature, chemical pollution, and population density are known stressors experienced by populations in agroecosystems.

Food stress, fluctuating asymmetry and reproductive performance in the gryllid crickets Gryllus bimaculatus and Gryllodes sigillatus

Behaviour ◽  
2004 ◽  
Vol 141 (2) ◽  
pp. 219-232 ◽  
Author(s):  
Samantha Mallard ◽  
C.J. Barnard
Keyword(s):  
Reproductive Performance ◽  
Fluctuating Asymmetry ◽  
Developmental Stress ◽  
Gryllus Bimaculatus ◽  
Food Treatment ◽  
General Hypothesis ◽  
Food Stress ◽  
Effect Of Food ◽  
Gryllodes Sigillatus ◽  
Measures Of Performance

AbstractWhile associations between sexual selection, developmental stress and fluctuating asymmetry (FA) remain controversial, this does not necessarily undermine the more general hypothesis that FA reflects developmental instability and functional competence. This applies as much to reproductive processes as to any other. If this is the case, however, we should expect FA and measures of performance to covary under conditions of developmental stress. Using an established association between morphometric FA and reproductive performance in the gryllid crickets Gryllus bimaculatus and Gryllodes sigillatus, we looked at the effect of food stress on covariation between FA and measures of performance (vigour of locomotion and interaction, mating speed, sperm transfer, egg production and offspring weight). The results showed a clear effect of food treatment in males and females of both species, with composite measures reflecting greater FA and reduced performance being greatest when crickets were reared on impoverished food. Inspection of independent means suggested FA may have been most influenced by a relaxation of food stress under high quality feeding conditions, while reproductive performance was more susceptible to the reduction in food quality under low quality conditions.

scholarly journals Fluctuating Asymmetry: A Technique for Measuring Developmental Stress Caused by Inbreeding

1986 ◽  
Vol 39 (2) ◽  
pp. 145 ◽  
Author(s):  
GM Clarke ◽  
GW Brand ◽  
MJ Whitten
Keyword(s):  
Fluctuating Asymmetry ◽  
Harpacticoid Copepod ◽  
Breeding Systems ◽  
Developmental Stress ◽  
Developmental Homeostasis ◽  
The Common ◽  
Inbreeding Level ◽  
The Relationship

Fluctuating asymmetry has sometimes been employed to indicate disruption of developmental homeostasis. Such disruption is thought to be a result of increased developmental stress. In this study we examine the relationship between fluctuating asymmetry and inbreeding level in two differing breeding systems: the marine harpacticoid copepod Tisbe holothuriae, a typically outbreeding diploid, and the common honeybee Apis melli/era, which is haplo-diploid. Inbreeding has previously been shown to constitute a developmental stress in populations of T. holothuriae, but the same is yet to be conclusively shown in A. melli/era.

Fluctuating asymmetry in certain morphological traits in laboratory populations of Drosophila ananassae

Genome ◽  
2006 ◽  
Vol 49 (7) ◽  
pp. 777-785 ◽  
Author(s):  
C Vishalakshi ◽  
B N Singh
Keyword(s):  
Fluctuating Asymmetry ◽  
Morphological Traits ◽  
Composite Index ◽  
Developmental Instability ◽  
Drosophila Ananassae ◽  
Developmental Stress ◽  
Phenotypic Quality ◽  
Laboratory Populations ◽  
Males And Females ◽  
Sexual Traits

Fluctuating asymmetry (FA, subtle random deviations from perfect bilateral symmetry) is often used as a measure of developmental instability (DI), which results from perturbations in developmental pathways caused by genetic or environmental stressors. During the present study, we estimated FA in 5 morphological traits, viz. wing length (WL), wing to thorax ratio (W:T), sternopleural bristle number (SBN), sex-comb tooth number (SCTN), and ovariole number (ON) in 18 laboratory populations of Drosophila ananassae. FA levels of measured traits differed significantly among populations except for SBN (in males and females) and W:T ratio (in females). Positional fluctuating asymmetry (PFA), a sensitive measure of DI, also varied significantly among the populations for SBN in females and SCTN in males. Interestingly, both males and females were similar for nonsexual traits. However, when FA across all traits (sexual and nonsexual) was combined into a single composite index (CFA), significant differences were found for both populations and sexes. Males showed higher CFA values than females, suggesting that males are more prone to developmental perturbations. The magnitude of FA differed significantly among traits, being lowest for nonsexual traits (SBN, WL, W:T ratio) and highest for sexual traits (SCTN and ON). The trait size of sexual traits (SCTN and ON) was positively correlated with their asymmetry. The possible reasons for variation in FA both among traits and among populations, and the usefulness of FA as an indicator of developmental stress and phenotypic quality in D. ananassae are discussed.Key words: fluctuating asymmetry, developmental instability, morphological traits, laboratory populations, D. ananassae.

scholarly journals Symmetry Preference as a Cognitive By-Product in Starlings

Behaviour ◽  
2004 ◽  
Vol 141 (4) ◽  
pp. 469-478 ◽  
Author(s):  
John Swaddle ◽  
R. Earl Clelland ◽  
Judy Che
Keyword(s):  
Fluctuating Asymmetry ◽  
Sturnus Vulgaris ◽  
Learning Processes ◽  
Developmental Stress ◽  
Developmental History ◽  
European Starlings ◽  
Visual Cue ◽  
Developmental Homeostasis ◽  
Behavioural Interactions ◽  
Or Genes

AbstractThere has been a great deal of interest in whether animals use trait symmetry as a visual cue to mediate behavioural interactions. In bilaterally symmetric traits, small asymmetries (termed fluctuating asymmetry) appear due to increased developmental stress and/or genes for poor developmental homeostasis. Hence, researchers have hypothesized that symmetry can reveal the developmental history and, perhaps, fitness of an individual and this is why symmetry preferences have been observed. However, an additional theory suggests that symmetry could be preferred merely because it represents the average expression of bilateral traits. Animals can learn to respond to signals by generalizing (or averaging) stimulus sets. As the average expression of a trait showing fluctuating asymmetry is zero asymmetry, theory predicts that animals could develop a symmetry preference as a by-product of learning. Here, we test this prediction empirically with European starlings (Sturnus vulgaris) and show that symmetry preferences can emerge as an outcome of generalized learning processes. Our results indicate that symmetry does not initially need to be associated with fitness to be an apparent cue in behavioural interactions and that symmetry preferences observed in nature could be independent of any putative fitness relationships.

Fluctuating asymmetry in the skeleton of the American kestrel, Falco sparverius: a test of the consequences of sexual size dimorphism

1995 ◽  
Vol 73 (1) ◽  
pp. 141-145 ◽  
Author(s):  
Gary R. Bortolotti ◽  
Joan R. Gabrielson
Keyword(s):  
Fluctuating Asymmetry ◽  
Statistical Significance ◽  
Bilateral Symmetry ◽  
Female Dominance ◽  
Falco Sparverius ◽  
Developmental Stress ◽  
American Kestrel ◽  
Food Shortages ◽  
Limited Food ◽  
The Cost

Fluctuating asymmetry, i.e., random, subtle departures from perfect bilateral symmetry, is believed to be a measure of developmental noise. The more physical stress an organism has undergone, the greater the asymmetry. We investigated the degree of fluctuating asymmetry in bones of the American kestrel (Falco sparverius) as a test of the developmental consequences of sexual dimorphism in size. The "cost of rearing" hypothesis predicts that females, because of their larger size, will suffer food shortages more often than males and hence show greater asymmetry. In contrast, the "female dominance" hypothesis predicts that females will be under less developmental stress because their size gives them an advantage when they compete with their brothers for limited food while in the nest. Significant fluctuating asymmetry was detected for all characters of both sexes; however, differences between males and females only approached statistical significance. We suggest that the degree of among-broods variation is so great that the role of gender in influencing developmental stability may be relatively small.

scholarly journals Drosophila melanogaster Response to Feeding with Neomycin-Based Medium Expressed in Fluctuating Asymmetry

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 378
Author(s):  
Kemal Büyükgüzel ◽  
Ender Büyükgüzel ◽  
Ewa Chudzińska ◽  
Anetta Lewandowska-Wosik ◽  
Renata Gaj ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Fluctuating Asymmetry ◽  
Fruit Fly ◽  
Model Organisms ◽  
Control Group ◽  
Developmental Stress ◽  
Type D ◽  
Wide Range ◽  
Electron And Light Microscopy ◽  
Anal Papillae

The fruit fly Drosophila melanogaster is a model species used for a wide range of studies. Contamination of Drosophila cultures with bacterial infection is common and is readily eradicated by antibiotics. Neomycin antibiotics can cause stress to D. melanogaster’s larvae and imagoes, which may affect the interpretation of the results of research using culture from neomycin-based medium. In the present study, fluctuating asymmetry (FA), one of the important bioindicators of stress, was measured. Larvae and imagoes of a wild-type D. melanogaster strain were exposed to various concentrations of neomycin. The size of anal papillae and selected wing veins were measured using scanning electron and light microscopy, respectively. Next, the FA was checked. The values obtained for larval anal papillae appeared to be concentration-dependant; the FA indices increased with the concentration of neomycin. The wing FA presented a large but variable correlation, depending on the measured vein. However, the mean length of veins was the highest for the control group, with neomycin-exposed groups showing lower values. The research showed that neomycin may cause sublethal stress in D. melanogaster, which manifests in increased FA indices. This suggests that neomycin can cause physiological and developmental stress in insects, which should be taken into account when interpreting the results of studies using these model organisms.

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