Fluctuating Asymmetry, Developmental Noise and Developmental Stability: Future Prospects for the Population Developmental Biology Approach

Abstract

Developmental noise—which level may vary within a certain backlash allowed by natural selection—is a reflection of the state of a developing system or developmental stability. Phenotypic variations inside the genetically determined norm observed in case of fluctuating asymmetry provide a unique opportunity for evaluating this form of ontogenetic variability. Low levels of developmental noise for the biologic system under study is observed under certain conditions, while its increase acts as a measure of stress. The concordance of changes in developmental stability with changes in other parameters of developmental homeostasis indicates the significance of fluctuating asymmetry estimates. All this determines the future prospects of the study of fluctuating asymmetry not only for developmental biology, but also for population biology. The study of developmental stability may act as the basis of an approach of population developmental biology to assess the nature of the phenotypic diversity and the state of natural populations under various impacts and during evolutionary transformations.

Fluctuating Asymmetry and Stress in Macaca fuscata: Does Captivity Affect Morphology?

“…The degree and modes of anatomical asymmetry have been extensively studied for decades both in vertebrates and invertebrates [1][2][3][4][5][6][7][8][9][10][11]. In nature, we can observe principally three different types of asymmetry:…”

Canalization and developmental stability of the yellow-necked mouse (Apodemus flavicollis) mandible and cranium related to age and nematode parasitism

“…Studies of experimental developmental biology use animals characterized by low levels of genetic variation, such as inbred mice and rats, and control environmental factors, whereas in natural populations multiple genetic and environmental determinants act on magnitude and pattern of morphological variation. On the other hand, development of a population developmental biology approach based on developmental stability study in natural populations is recognized by Zakharov et al [ 4 ] as particularly promising for solving various problems in a practice of population studies as well as for obtaining information on the state of homeorhesis in nature for developmental biology. Finally, to make reasonable predictions about how a covariance structure among and/or within individuals, i.e.…”

“…Developmentally and functionally complex morphological structures, such as mammalian mandible and cranium, are well-established model systems for studying canalization, developmental stability (DS), and morphological integration, recognized by Hallgrímsson et al [ 1 ] as three main components of phenotypic variability. Canalization and DS also represent two elements of developmental homeostasis or homeorhesis, the mechanism responsible for ensuring phenotypic constancy in organisms despite the great variability of genetic and environmental features [ 2 – 4 ]. According to early explanations of canalization and DS, the former is considered as the buffering of developmental processes against environmental and mutational perturbations, and the latter as the ability of developmental processes to buffer random developmental noise that arises within the developmental processes themselves [ 5 , 6 ].…”

“…The factors that may disturb developmental homeostasis can be of environmental or genetic origin [ 14 ]. Traditional and geometric morphometric methods have been used frequently in a wide range of organisms, from plants to humans, for examining whether various environmental and genetic factors disrupt the level of canalization and DS [ 1 , 4 , 9 , 12 , 14 – 20 ]. In the 1990s geometric morphometric methods offered new tools for exploring patterns of morphological variation, i.e.…”

Geometric Morphometrics of Bilateral Asymmetry in Eunotia bilunaris (Eunotiales, Bacillariophyceae) as a Tool for the Quantitative Assessment of Teratogenic Deviations in Frustule Shapes

“…However, this asymmetry cannot be decomposed into directional and fluctuating components, as in the standard procedure of a two-factor, mixed-effect analysis of variance (ANOVA) model that is frequently used in geometric morphometric studies of bilateral symmetry in multicellular organisms [18]. Consequently, fluctuating asymmetry could not be used in these diatoms as an explicit measure of individual stress or developmental instability among specimens [34] because frustules of eunotioid diatoms typically lack any unambiguous directional orientation of their two symmetrical halves delimited by the transapical axis. In a set of such objects, the individual halves cannot be unambiguously designated as "right" or "left."…”