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Vladimir M Zakharov - One of the best experts on this subject based on the ideXlab platform.

  • Fluctuating Asymmetry, Developmental Noise and Developmental Stability: Future Prospects for the Population Developmental Biology Approach
    Symmetry, 2020
    Co-Authors: Vladimir M Zakharov, Elena Shadrina, I. E. Trofimov
    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.

  • Developmental Stability and population dynamics of shrews Sorex in central Siberia
    Acta Theriologica, 1997
    Co-Authors: Vladimir M Zakharov, Alexander S. Baranov, Dmitry V. Demin, Vyacheslav I. Borisov, Alexey V. Valetsky, Boris I Sheftel
    Abstract:

    We examined temporal variation in Developmental Stability measured by fluctuating asymmetry of 10 skull characters in sympatric populations of three shrew species: Sorex araneus Linnaeus, 1758, S. caecutiens Laxmann, 1788 and S. tundrensis Merriam, 1900 from one locality in central Siberia with a high four-year-cycle of small mammals. Simultaneous significant changes in Developmental Stability have been revealed during a population cycle 1986-1989 for all three, most abundant shrew species in the locality. The highest asymmetry for all these species occurred in the year of maximal density. Similar high asymmetry was found for the separate samples of two other species: S. roboratus Hollister, 1913 and S. isodon Turov, 1924, collected in a peak year 1989 only. The maximal density in 1989 corresponded to the lowest level of breeding success and Developmental Stability and, vice versa, minimal density in 1986 was accompanied by the highest level of breeding success and Developmental Stability. These data suggest that overpopulation caused by high density of various small mammals adversely affects an organism's condition. Thus, Developmental Stability may be used to monitor possible changes in a population even in cases where direct estimation of fitness is difficult.

  • Developmental Stability of the mink Mustela vison under the impact of PCB
    Acta Theriologica, 1997
    Co-Authors: Vyacheslav I. Borisov, Alexander S. Baranov, Alexey V. Valetsky, Vladimir M Zakharov
    Abstract:

    Females of the American mink Mustela vison Schreber, 1777 were fed on various fractions of comercial PCB. Developmental Stability of their progeny was studied. Developmental Stability was measured by the value of fluctuating asymmetry, and the frequency of phenodeviants of osteological and dermatoglyphic characters. All these measures proved to be significantly higher in the experimental intoxicated groups than in the control group, thus indicating deterioration of Developmental Stability from PCB.

  • Bisoniana 113. Developmental Stability of skull morphology in European bison Bison bonasus
    Acta Theriologica, 1997
    Co-Authors: Alexander S. Baranov, Zdzisław Pucek, E. G. Kiseleva, Vladimir M Zakharov
    Abstract:

    Authors compared Developmental Stability and total phenotypic diversity of 25 skull characters in three populations of European bison Bison bonasus (Linnaeus, 1758). Developmental Stability was measured by fluctuating asymmetry, which was estimated by the variance of the left-right (l-r) and scaled (l-r)/(l+r) differences between the left (l) and right (r) sides of the skull. Mean number of asymmetrical characters per individual was used as an integrated index of Developmental Stability.

  • Inbreeding and outbreeding impact on Developmental Stability of laboratory rat Ratus norvegicus
    Acta Theriologica, 1997
    Co-Authors: Vyacheslav I. Borisov, Alexey V. Valetsky, Irina L. Dmitrieva, Natalia L. Krushinskaya, Vladimir M Zakharov
    Abstract:

    Developmental Stability analysis was conducted for three strains of laboratory rat Rattus norvegicus Berkenhout, 1769 and their hybrids. Developmental Stability was estimated by fluctuating asymmetry of 20 characters of skull morphology. A decrease was revealed in fluctuating asymmetry for the inbred strains and for the hybrids of genetically different strains. There were not any differences in fluctuating asymmetry between the homo- and heterozygotes for the separate locus. This support the hypothesis of the dependence of Developmental Stability on general genetic coadaptation.

Brian K Hall - One of the best experts on this subject based on the ideXlab platform.

  • Canalization, Developmental Stability, and morphological integration in primate limbs
    American Journal of Physical Anthropology, 2002
    Co-Authors: Benedikt Hallgrímsson, Katherine E. Willmore, Brian K Hall
    Abstract:

    Canalization and Developmental Stability refer to the tendency of Developmental processes to follow particular trajectories, despite external or internal pertur- bation. Canalization is the tendency for development of a specific genotype to follow the same trajectory under differ- ent conditions (different environments or different genetic backgrounds), while Developmental Stability is the tendency for the development of a specific genotype to follow the same trajectory under the same conditions. Morphological integra- tion refers to the tendency for structures to show correlated variation because they develop in response to shared devel- opmental processes or function in concert with other struc- tures. All three phenomena are emergent properties of de- velopmental systems that can affect the interaction of development and evolution. In this paper, we review the topics of canalization, Developmental Stability, and morpho- logical integration and their relevance to primate and hu- man evolution. We then test three Developmentally moti- vated hypotheses about the patterning of variability components in the mammalian limb. We find that environ- mental variances and fluctuating asymmetries (FA) increase distally along the limb in adult macaques but not in fetal mice. We infer that the greater variability of more distal segments in macaques is due to postnatal mechanical ef- fects. We also find that heritability and FA are significantly correlated when different limb measurements are compared in fetal mice. This supports the idea that the mechanisms underlying canalization and Developmental Stability are re- lated. Finally, we report that the covariation structure of fore- and hindlimb skeletal elements shows evidence for morphological integration between serially homologous structures between the limbs. This is evidence for the exis- tence of Developmental modules that link structures be- tween the limbs. Such modules would produce covariation that would need to be overcome by selection for divergence in hind- and forelimb morphology. Yrbk Phys Anthropol 45: 131-158, 2002. © 2002 Wiley-Liss, Inc.

  • Canalization, Developmental Stability, and morphological integration in primate limbs.
    American journal of physical anthropology, 2002
    Co-Authors: Benedikt Hallgrímsson, Katherine Willmore, Brian K Hall
    Abstract:

    Canalization and Developmental Stability refer to the tendency of Developmental processes to follow particular trajectories, despite external or internal perturbation. Canalization is the tendency for development of a specific genotype to follow the same trajectory under different conditions (different environments or different genetic backgrounds), while Developmental Stability is the tendency for the development of a specific genotype to follow the same trajectory under the same conditions. Morphological integration refers to the tendency for structures to show correlated variation because they develop in response to shared Developmental processes or function in concert with other structures. All three phenomena are emergent properties of Developmental systems that can affect the interaction of development and evolution. In this paper, we review the topics of canalization, Developmental Stability, and morphological integration and their relevance to primate and human evolution. We then test three Developmentally motivated hypotheses about the patterning of variability components in the mammalian limb. We find that environmental variances and fluctuating asymmetries (FA) increase distally along the limb in adult macaques but not in fetal mice. We infer that the greater variability of more distal segments in macaques is due to postnatal mechanical effects. We also find that heritability and FA are significantly correlated when different limb measurements are compared in fetal mice. This supports the idea that the mechanisms underlying canalization and Developmental Stability are related. Finally, we report that the covariation structure of fore- and hindlimb skeletal elements shows evidence for morphological integration between serially homologous structures between the limbs. This is evidence for the existence of Developmental modules that link structures between the limbs. Such modules would produce covariation that would need to be overcome by selection for divergence in hind- and forelimb morphology.

Christophe Pélabon - One of the best experts on this subject based on the ideXlab platform.

  • Effects of crossing distance on offspring fitness and Developmental Stability in Dalechampia scandens (Euphorbiaceae)
    American journal of botany, 2005
    Co-Authors: Christophe Pélabon, Thomas F. Hansen, Matthew L. Carlson, W. Scott Armbruster
    Abstract:

    Crosses between genetically close and distant populations of Dalechampia scandens (Euphorbiaceae) were made to test whether the responses of various fitness components and measurements of Developmental Stability were affected by the outcrossing distance (level of outbreeding). Two fecundity traits, seed set and seed mass, decreased consistently with increasing level of outbreeding, and hybrids between the most divergent populations were sterile. Effects of the genetic distance between parental populations on viability traits, survival and vigor at 1 month of age, were highly idiosyncratic. Hybrids of one long-distance combination had no reduction in survival and vigor, while both traits were greatly reduced in the other long-distance combination. The expression of outbreeding depression on fecundity traits differed between reciprocal crosses in some hybrids but not others; thus, hybrid breakdown may have been due to cytoplasmic-by-nuclear gene interactions, reduced endosperm formation, or an interaction between progeny and maternal genotype. None of the measures of Developmental Stability had a consistent relationship with either genetic distance between parental populations or seedling vigor. These results suggest that fecundity and viability traits may be differentially affected by hybridization, probably due to differences in genetic architecture among populations. This study also confirms that Developmental Stability, as measured by the level of fluctuating asymmetry, is not a reliable index of genetic stress.

  • Variational and genetic properties of Developmental Stability in Dalechampia scandens.
    Evolution; international journal of organic evolution, 2004
    Co-Authors: Christophe Pélabon, Thomas F. Hansen, Matthew L. Carlson, W. Scott Armbruster
    Abstract:

    Because low Developmental Stability may compromise the precision with which adaptations can be reached, the variability and genetic basis of Developmental Stability are important evolutionary parameters. Developmental Stability is also an important clue to understanding how traits are regulated to achieve their phenotypic target value. However, Developmental Stability must be studied indirectly through proxy variables, such as fluctuating asymmetry, that are suggested to have noisy and often nonlinear relationships to the underlying variable of interest. In this paper we first show that mean-standardized measures of variance and covariance in fluctuating asymmetry, unlike heritabilities, repeatabilities, and correlations, are linearly related to corresponding measures of variation in underlying Developmental Stability. We then examine the variational properties of Developmental Stability in a population of the Neotropical vine, Dalechampia scandens (Euphorbiaceae). By studying fluctuating asymmetry in a large number of floral characters in both selfed and outcrossed individuals in a diallel design, we assemble strong evidence that both additive genetic and individual variation and covariation in Developmental Stability are virtually absent in this population.

  • Consequences of inter‐population crosses on Developmental Stability and canalization of floral traits in Dalechampia scandens (Euphorbiaceae)
    Journal of evolutionary biology, 2003
    Co-Authors: Christophe Pélabon, Thomas F. Hansen, Matthew L. Carlson, Nigel G. Yoccoz, W. S. Armbruster
    Abstract:

    Congruence between changes in phenotypic variance and Developmental noise in inter-population hybrids was analysed to test whether environmental canalization and Developmental Stability were controlled by common genetic mechanisms. Developmental Stability assessed by the level of fluctuating asymmetry (FA), and canalization by the within- and among-individual variance, were measured on several floral traits of Dalechampia scandens (Euphorbiaceae). Hybridization affected canalization. Both within- and among-individual phenotypic variance decreased in hybrids from populations of intermediate genetic distance, and strongly increased in hybrids from genetically distant populations. Mean-trait FA differed among cross-types, but hybrids were not consistently more or less asymmetric than parental lines across traits. We found no congruence between changes in FA and changes in phenotypic variance. These results suggest that Developmental Stability (measured by FA) and canalization are independently controlled. This study also confirms the weak relationship between FA and the breakdown of coadapted gene complexes following inter-population hybridization.

W. Scott Armbruster - One of the best experts on this subject based on the ideXlab platform.

  • Effects of crossing distance on offspring fitness and Developmental Stability in Dalechampia scandens (Euphorbiaceae)
    American journal of botany, 2005
    Co-Authors: Christophe Pélabon, Thomas F. Hansen, Matthew L. Carlson, W. Scott Armbruster
    Abstract:

    Crosses between genetically close and distant populations of Dalechampia scandens (Euphorbiaceae) were made to test whether the responses of various fitness components and measurements of Developmental Stability were affected by the outcrossing distance (level of outbreeding). Two fecundity traits, seed set and seed mass, decreased consistently with increasing level of outbreeding, and hybrids between the most divergent populations were sterile. Effects of the genetic distance between parental populations on viability traits, survival and vigor at 1 month of age, were highly idiosyncratic. Hybrids of one long-distance combination had no reduction in survival and vigor, while both traits were greatly reduced in the other long-distance combination. The expression of outbreeding depression on fecundity traits differed between reciprocal crosses in some hybrids but not others; thus, hybrid breakdown may have been due to cytoplasmic-by-nuclear gene interactions, reduced endosperm formation, or an interaction between progeny and maternal genotype. None of the measures of Developmental Stability had a consistent relationship with either genetic distance between parental populations or seedling vigor. These results suggest that fecundity and viability traits may be differentially affected by hybridization, probably due to differences in genetic architecture among populations. This study also confirms that Developmental Stability, as measured by the level of fluctuating asymmetry, is not a reliable index of genetic stress.

  • Variational and genetic properties of Developmental Stability in Dalechampia scandens.
    Evolution; international journal of organic evolution, 2004
    Co-Authors: Christophe Pélabon, Thomas F. Hansen, Matthew L. Carlson, W. Scott Armbruster
    Abstract:

    Because low Developmental Stability may compromise the precision with which adaptations can be reached, the variability and genetic basis of Developmental Stability are important evolutionary parameters. Developmental Stability is also an important clue to understanding how traits are regulated to achieve their phenotypic target value. However, Developmental Stability must be studied indirectly through proxy variables, such as fluctuating asymmetry, that are suggested to have noisy and often nonlinear relationships to the underlying variable of interest. In this paper we first show that mean-standardized measures of variance and covariance in fluctuating asymmetry, unlike heritabilities, repeatabilities, and correlations, are linearly related to corresponding measures of variation in underlying Developmental Stability. We then examine the variational properties of Developmental Stability in a population of the Neotropical vine, Dalechampia scandens (Euphorbiaceae). By studying fluctuating asymmetry in a large number of floral characters in both selfed and outcrossed individuals in a diallel design, we assemble strong evidence that both additive genetic and individual variation and covariation in Developmental Stability are virtually absent in this population.

Anders Pape Møller - One of the best experts on this subject based on the ideXlab platform.

  • Developmental Stability and Signalling among Cells
    Journal of theoretical biology, 1998
    Co-Authors: Anders Pape Møller, Mark Pagel
    Abstract:

    The production of stable phenotypes depends from the earliest stages of development upon high levels of somatic cellular selection amongst cells or cell lineages. The signals exchanged amongst cells can reveal important aspects of a cell's phenotype, and might thereby be used in darwinian processes of Developmental selection. Based upon an optimality model, we suggest that stable phenotypes require a substantial investment in two mechanisms of inter-cellular selection: "quality-selection" mechanisms regulate the average phenotype of a group of cells; "Stability-selection" mechanisms regulate the variance in cell phenotypes. Variance in cell phenotypes may arise from Developmental-error or other stochastic processes, or be generated as is true of the immune system, as part of a Developmental strategy. The model shows that Stability-selection mechanisms may exert the stronger effect on overall organ or body performance. Selection based upon reliable inter-cellular signalling of phenotypic properties may be the key way that bodies anticipate and then constrain variance in cell phenotypes around the optimal cellular attributes, and suggests an advantage of Developmentally-selected systems over instructional ones. High levels of investments in Stability mechanisms also ensure homogeneous collections of cells that can translate "upwards" into Developmentally stable organ systems and phenotypes. Environmental and genetic factors, as well as the prevalent mode of selection, may all affect Developmental Stability and thereby give rise to varying of somatic selection.

  • Developmental Stability, DISEASE AND MEDICINE
    Biological reviews of the Cambridge Philosophical Society, 1997
    Co-Authors: Randy Thornhill, Anders Pape Møller
    Abstract:

    Developmental Stability reflects the ability of a genotype to undergo stable development of a phenotype under given environmental conditions. Deviations from Developmental Stability arise from the disruptive effects of a wide range of environmental and genetic stresses, and such deviations are usually measured in terms of fluctuating asymmetry and phenodeviants. Fluctuating asymmetry is the most sensitive indicator of the ability to cope with stresses during ontogeny. There is considerable evidence that Developmental Stability, and especially fluctuating asymmetry, is a useful measure of phenotypic and genetic quality, because it covaries negatively with performance in multiple fitness domains in many species, including humans. It is proposed that Developmental Stability is an important marker of human health. Our goal is to initiate formally the integration of the sciences of evolutionary biology, Developmental biology and medicine. We believe that this integrative framework provides a significant addition to the growing field of Darwinian medicine. The literature linking Developmental Stability and disease in humans is reviewed. Recent biological theoretical treatments pertaining to Developmental Stability are applied to a range of human health issues such as genetic diseases, ageing and survival, subfertility, abortion, child maltreatment by parents, cancer, infectious diseases, physiological and mental health, and physical attractiveness as a health certification.

  • A meta‐analysis of the heritability of Developmental Stability
    Journal of Evolutionary Biology, 1997
    Co-Authors: Anders Pape Møller, Randy Thornhill
    Abstract:

    The existence of additive genetic variance in Developmental Stability has important implications for our understanding of morphological variation. The heritability of individual fluctuating asymmetry and other measures of Developmental Stability have frequently been estimated from parent-offspring regressions, sib analyses, or from selection experiments. Here we review by meta-analysis published estimates of the heritability of Developmental Stability, mainly the degree of individual fluctuating asymmetry in morphological characters. The overall mean effect size of heritabilities of individual fluctuating asymmetry was 0.19 from 34 studies of 17 species differing highly significantly from zero (P < 0.0001). The mean heritability for 14 species was 0.27. This indicates that there is a significant additive genetic component to Developmental Stability. Effect size was larger for selection experiments than for studies based on parent-offspring regression or sib analyses, implying that genetic estimates were unbiased by maternal or common environment effects. Additive genetic coefficients of variation for individual fluctuating asymmetry were considerably higher than those for character size per se. Developmental Stability may be significantly heritable either because of strong directional selection, or fluctuating selection regimes which prevent populations from achieving a high degree of Developmental Stability to current environmental and genetic conditions.

  • a meta analysis of the heritability of Developmental Stability
    Journal of Evolutionary Biology, 1997
    Co-Authors: Anders Pape Møller, Randy Thornhill
    Abstract:

    The existence of additive genetic variance in Developmental Stability has important implications for our understanding of morphological variation. The heritability of individual fluctuating asymmetry and other measures of Developmental Stability have frequently been estimated from parent-offspring regressions, sib analyses, or from selection experiments. Here we review by meta-analysis published estimates of the heritability of Developmental Stability, mainly the degree of individual fluctuating asymmetry in morphological characters. The overall mean effect size of heritabilities of individual fluctuating asymmetry was 0.19 from 34 studies of 17 species differing highly significantly from zero (P < 0.0001). The mean heritability for 14 species was 0.27. This indicates that there is a significant additive genetic component to Developmental Stability. Effect size was larger for selection experiments than for studies based on parent-offspring regression or sib analyses, implying that genetic estimates were unbiased by maternal or common environment effects. Additive genetic coefficients of variation for individual fluctuating asymmetry were considerably higher than those for character size per se. Developmental Stability may be significantly heritable either because of strong directional selection, or fluctuating selection regimes which prevent populations from achieving a high degree of Developmental Stability to current environmental and genetic conditions.

  • Developmental Stability and fitness: a review.
    The American naturalist, 1997
    Co-Authors: Anders Pape Møller
    Abstract:

    Abstract Developmental Stability reflects the ability of individuals to undergo stable development of their phenotype under a range of environmental conditions. Developmental inStability is measured in terms of fluctuating asymmetry or phenodeviance. A negative relationship between Developmental inStability and fitness has figured as a prominent untested assumption in the literature. A review of available information from the literature on the relationship between Developmental inStability and various fitness components such as growth, fecundity, and longevity suggests that there indeed is a general negative relationship. Symmetrical individuals do generally have faster growth, higher fecundity, and better survival than do more asymmetrical individuals. These differences appear partially to arise from lower competitive ability and higher risks of predation and parasitism of asymmetrical individuals compared with more symmetrical conspecifics. The relationship between Developmental Stability and fitness ma...