scholarly journals Developmental instability in wild Nigerian olive baboons (Papio anubis)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11832
Author(s):  
Kara C. Hoover ◽  
Emily Gelipter ◽  
Volker Sommer ◽  
Kris Kovarovic

Background Developmental instability in archaeological samples can be detected through analysis of skeletal and dental remains. During life, disruptions to biological internal homeostasis that occur during growth and development redirect bodily resources to returning to homeostasis and away from normal processes such as symmetrical development. Because dental enamel does not remodel in life, any deviations from normal development are left behind. Even subtle disturbances to developmental trajectory may be detected in asymmetrical development of traits, specifically a random variation in sides termed fluctuating asymmetry. Human dental fluctuating asymmetry studies are common, but here we investigate the permanent dentition of a non-human primate Papio anubis, for potential fluctuating asymmetry relative to sex, weaning, and reproductive maturity. The sample stems from an outlier population that lives in the wettest and most humid habitat of any studied baboon group. Methods The skulls of adult baboons were collected after their natural death in Gashaka Gumti National Park, Nigeria. The permanent dentition of antimeric teeth (paired) were measured for maximum length and breadth using standard methods. The metrics were analyzed to assess the presence of fluctuating asymmetry in adult permanent mandibular and maxillary dentition. Measurement error and other forms of asymmetry (antisymmetry, directional asymmetry) were considered and dental measures expressing true fluctuating asymmetry were used to address three research questions. Results Males exhibit greater fluctuating asymmetry than females, suggesting that males experience greater overall instability during the developmental period. While weaning is not more stressful than other life history stages for males and females (using the first molar fluctuating asymmetry index as a proxy compared to other teeth), it is more stressful for females than males. The onset of reproduction is also not more stressful than other life history stages for males and females (using the third molar fluctuating asymmetry index as a proxy compared to other teeth), but it is more stressful for males than females. We explore possible explanations for these findings in the discussion.

Genome ◽  
2006 ◽  
Vol 49 (7) ◽  
pp. 777-785 ◽  
Author(s):  
C Vishalakshi ◽  
B N Singh

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.


2020 ◽  
Vol 60 ◽  
pp. e20206039
Author(s):  
Pere M. Parés-Casanova ◽  
Pinzón Brando ◽  
Daniel Caviedes ◽  
Arcesio Salamanca-Carreño

The ability of an individual to withstand random perturbations during its development is considered a good indicator of environmental and genetic stress. A common means of assessing developmental stability is through analysis of fluctuating asymmetry (FA) in bilateral traits. Tortoises, with their large, solid plastron, allow for measurement of body geometry. Their bilateral shell scutes are ideal candidates for asymmetries researches. With this issue in mind we assessed, as a preliminary study, levels of plastron scute asymmetry in a sample of 46 red-footed tortoise Chelonoidis carbonaria from Arauca, N Colombia. We found significative fluctuating asymmetry (FA) but no directional asymmetry, the former not increasing with carapace size and thus indicating that tortoise shells do not become increasingly asymmetrical with age, or in other words, signaling that FA is not being influenced by pholidosis (variability of scale cover mosaic according to the development of the scutes). Asymmetry in plastron shape, although not necessarily apparent at first glance, varied, with gender with males exhibiting higher levels of FA than females. Although we can not identify the potential sources of variation responsible for the observed patterns of developmental instability, we consider this detected form of asymmetry due to unfavorable environmental conditions.


Author(s):  
Camilo López-Aguirre ◽  
Suzanne J. Hand ◽  
Daisuke Koyabu ◽  
Vuong Tan Tu ◽  
Laura A. B. Wilson

Fluctuating asymmetry (random fluctuations between the left and right sides of the body) has been interpreted as an index to quantify both the developmental instabilities and homeostatic capabilities of organisms, linking the phenotypic and genotypic aspects of morphogenesis. However, studying the ontogenesis of fluctuating asymmetry has been limited to mostly model organisms in postnatal stages, missing prenatal trajectories of asymmetry that could better elucidate decoupled developmental pathways controlling symmetric bone elongation and thickening. In this study, we quantified the presence and magnitude of asymmetry during the prenatal development of bats, focusing on the humerus, a highly specialized bone adapted in bats to perform under multiple functional demands. We deconstructed levels of asymmetry by measuring the longitudinal and cross-sectional asymmetry of the humerus using a combination of linear measurements and geometric morphometrics. We tested the presence of different types of asymmetry and calculated the magnitude of size-controlled fluctuating asymmetry to assess developmental instability. Statistical support for the presence of fluctuating asymmetry was found for both longitudinal and cross-sectional asymmetry, explaining on average 16% of asymmetric variation. Significant directional asymmetry accounted for less than 6.6% of asymmetric variation. Both measures of fluctuating asymmetry remained relatively stable throughout ontogeny, but cross-sectional asymmetry was significantly different across developmental stages. Finally, we did not find a correspondence between developmental patterns of longitudinal and cross-sectional asymmetry, indicating that processes promoting symmetrical bone elongation and thickening work independently. We suggest various functional pressures linked to newborn bats’ ecology associated with longitudinal (altricial flight capabilities) and cross-sectional (precocial clinging ability) developmental asymmetry differentially. We hypothesize that stable magnitudes of fluctuating asymmetry across development could indicate the presence of developmental mechanisms buffering developmental instability.


2010 ◽  
Vol 60 (2) ◽  
pp. 169-182 ◽  
Author(s):  
Clara Ten Broek ◽  
Liliane Wijnaendts ◽  
Frietson Galis ◽  
Stefan Van Dongen

AbstractThe often observed directional asymmetry in human limb bones could have a genetic basis. Alternatively, differences in limbs across sides could emerge from different mechanical loadings on the left and right side as a result of behavioral lateralization. Because handedness in itself has a genetic basis, it has been suggested that directional asymmetry in limbs could develop prenatally as a pre-adaptation to adult life. The developmental origins of limb asymmetry and the presence of directional asymmetry have important implications for the use of directionally random asymmetry (i.e., fluctuating asymmetry) as a measure of developmental instability (the inability of an organism to buffer its development against random noise). We study asymmetry in limb bones of deceased fetuses. We predict that if the direct effects of handedness (asymmetric mechanical loadings) would predominantly affect directional asymmetry, it would be absent in fetal limbs. However, because genes involved in the asymmetrical positioning of internal organs (situs solitus) also play a role in limb development, directional asymmetry may also emerge during early fetal stages. In a sample of over 500 fetuses, no indication of directional asymmetry was found in several limb bones. In addition, directional asymmetry did not emerge in the older fetuses either. We suggest that morphological asymmetries in fetal limb bones corresponded to fluctuating asymmetry measuring developmental instability. High levels of developmental integration found in our dataset could explain the overall low levels of asymmetry found in our study.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3359
Author(s):  
Clara M.A. ten Broek ◽  
Jessica Bots ◽  
Marianna Bugiani ◽  
Frietson Galis ◽  
Stefan Van Dongen

Disturbance from the normal developmental trajectory of a trait during growth—the so-called developmental instability—can be observed morphologically through phenodeviants and subtle deviations from perfect symmetry (fluctuating asymmetry). This study investigates the relationship between phenodeviance in the human vertebral column (as a result of axial patterning defects) and limb fluctuating asymmetry. Since both types of markers of developmental instability have been found associated with congenital abnormalities in humans, we anticipate a relationship between them if the concept of developmental instability, measured through either phenodeviants or asymmetry, would reflect an organism-wide process. Yet we did not find any support for this hypothesis. We argue that the vast differences in the developmental processes involved in both systems renders these two markers of developmental instability unrelated, in spite of their associations with other congenital abnormalities. Our results thus contribute to the growing awareness that developmental instability is not an organism-wide property.


Author(s):  
Dr. Minti Kumari ◽  
Dr. Madhuri Kumari ◽  
Dr Anurag Rai ◽  
Dr. Navin Kumar

It is evident that hyperdontia is more common in the permanent dentition than in the primary. There is a considerable difference between males and females in the prevalence of these teeth in permanent dentition; hyperdontia is twice as common in males as in females. However, this approximation varies in terms of location, other associating syndromes that may be present, and the ethnicity of the individual. In terms of ethnicity, it can be seen that hyperdontia is in fact less common in Caucasian than in Asian populations. There is evidence to show that an individual is more likely to have hyperdontia if other members of their family also have the condition. Hence the present study was planned for evaluation of occurrence of hyperdontia in non-syndromic  population from Bihar Region. The present study was planned in Public Health Dentistry, Patna Dental College and Hospital, Patna, Bihar. Total 195 patients referred to Department of Dentistry were evaluated in the present study. Panoramic radiographs and clinical records of patients above the age of 18 years and without any syndromic features were selected for the study.  All the radiographs were examined for the presence of supernumerary teeth, their location, morphology, and number. Morphologically, teeth were classified as conical, tuberculate, supplemental, and odontoma. Early diagnosis of dental anomalies can prevent some esthetic, orthodontic, and periodontal problems, and knowledge of the prevalence and distribution of the anomalies may help clinicians to the detection of these anomalies at early stages. Our study evaluated the prevalence of selected dental anomalies; future studies should investigate the prevalence of dental anomalies of all types. Keywords: Hyperdontia, non-syndromic, panoramic radiograph, supernumerary teeth, etc.


2020 ◽  
Vol 27 (4) ◽  
pp. 195-200
Author(s):  
Ufuk Bülbül ◽  
Halime Koç ◽  
Yasemin Odabaş ◽  
Ali İhsan Eroğlu ◽  
Muammer Kurnaz ◽  
...  

Age structure of the eastern spadefoot toad, Pelobates syriacus from the Kızılırmak Delta (Turkey) were assessed using phalangeal skeletochronology. Snout-vent length (SVL) ranged from 42.05 to 86.63 mm in males and 34.03 to 53.27 mm in females. Age of adults ranged from 2 to 8 years in males and 3 to 5 years in females. For both sexes, SVL was significantly correlated with age. Males and females of the toads reached maturity at 2 years of age.


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.


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