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PubMed2005

Putting prey back together again: integrating predator-induced behavior, morphology, and life history.

The last decade has seen an explosion in the number of studies exploring predator-induced plasticity. Recently, there has been a call for more comprehensive approaches that can identify functional relationships between traits, constraints on phenotypic responses, and the cost and benefits of alternative phenotypes. In this study, we exposed Helisoma trivolvis, a freshwater snail, to a factorial combination of three resource levels and five predator environments (no predator, one or two water bugs, and one or two crayfish) and examined ten traits including behavior, morphology, and life history. Each predator induced a unique suite of behavioral and morphological responses. Snails increased near-surface habitat use with crayfish but not with water bugs. Further, crayfish induced narrow and high shells whereas water bugs induced wide shells and wide apertures. In terms of life history, both predators induced delayed reproduction and greater mass at reproduction. However, crayfish induced a greater delay in reproduction that resulted in reduced fecundity whereas water bugs did not induce differences in fecundity. Resource levels impacted the morphology of H. trivolvis; snails reared with greater resource levels produced higher shells, narrower shells, and wider apertures. Resource levels also impacted snail life history; lower resources caused longer times to reproduction and reduced fecundity. Based on an analysis of phenotypic correlations, the morphological responses to each predator most likely represent phenotypic trade-offs. Snails could either produce invasion-resistant shells for defense against water bugs or crush-resistant shells for defense against crayfish, but not both. Our use of a comprehensive approach to examine the responses of H. trivolvis has provided important information regarding the complexity of phenotypic responses to different environments, the patterns of phenotypic integration across environments, and the potential costs and benefits associated with plastic traits.

Analysis of Variance↗

PubMed2005

Ecological consequences of phenotypic plasticity.

Phenotypic plasticity is widespread in nature, and often involves ecologically relevant behavioral, physiological, morphological and life-historical traits. As a result, plasticity alters numerous interactions between organisms and their abiotic and biotic environments. Although much work on plasticity has focused on its patterns of expression and evolution, researchers are increasingly interested in understanding how plasticity can affect ecological patterns and processes at various levels. Here, we highlight an expanding body of work that examines how plasticity can affect all levels of ecological organization through effects on demographic parameters, direct and indirect species interactions, such as competition, predation, and coexistence, and ultimately carbon and nutrient cycles.

Journal Article↗

PubMed2004

Comparative analysis of morphological traits among Drosophila melanogaster and D. simulans: genetic variability, clines and phenotypic plasticity.

The two sibling cosmopolitan species, Drosophila melanogaster and D. simulans, are able to proliferate under very different climatic conditions. This has resulted in local adaptations, which are often arranged in latitudinal clines. Such clines are documented for body weight, wing and thorax length, sternopleural and abdominal bristle number, ovariole number and thoracic pigmentation. The overall magnitude of geographical differentiation is, however, much less in D. simulans than in D. melanogaster, and latitudinal clines are less pronounced. The fact that natural populations live under different climates raises the problem of interaction between temperature and phenotype. The reaction norms of morphometrical traits have been investigated as a function of growth temperature. The shapes of the response curves vary according to the investigated trait. They are generally curvilinear and can be described by calculating characteristic values after polynomial adjustments. For a given trait, the reaction norms of the two species are similar in their shape, although some significant differences may be observed. Within each species, significant differences are also observed between geographic populations: reaction norms are not parallel and the divergence is better marked when more distant populations (e.g., temperate and tropical) are compared. It thus appears that besides mean trait value, phenotypic plasticity is also a target of natural selection. A specific analysis of wing shape variation according to growth temperature was also undertaken. Reaction norms with different shapes may be observed in various parts of the wing: the major effect is found between the basis and the tip of the wing, but in a similar way in the two species. By contrast, some ratios, called wing indices by taxonomists, may exhibit completely different reaction norms in the two species. For a single developmental temperature (25 degrees C) the phenotypic variability of morphometrical traits is generally similar in the two species, and also the genetic variability, estimated by the intraclass correlation. A difference exists, however, for the ovariole number which is less variable in D. simulans. Variance parameters may vary according to growth temperature, and a detailed analysis was made on wing dimensions. An increase of environmental variability at extreme, heat or cold temperatures, has been found in both species. Opposite trends were, however, observed for the genetic variability: a maximum heritability in D. simulans at middle temperatures, corresponding to a minimum heritability in D. melanogaster. Whether such a difference exists for other traits and in other populations deserves further investigations. In conclusion, morphometrical analyses reveal a large amount of significant differences which may be related to speciation and to the divergence of ecological niches. Within each species, numerous geographic variations are also observed which, in most cases, reflect some kinds of climatic adaptation.

Animals↗

PubMed2005

Shade tolerance plasticity in response to neutral vs green shade cues in Polygonum species of contrasting ecological breadth.

Here we examined species differences in perception and response to two distinct types of shade cue, reduced photosynthetically active radiation (PAR) with and without reduced red : far red ratio (R : FR), in Polygonum persicaria and Polygonum hydropiper, two closely related annuals of contrasting ecological breadth. We compared plasticity data for light-gathering traits from glasshouse experiments at equivalently reduced PAR under neutral shade (R : FR 1.03) and green shade (R : FR 0.702). Species shared the ability to distinguish between the two types of shade, as shown by the ability of each to respond differently to neutral vs green shade for one or more traits. However, the species' responses to these cues differed significantly. Polygonum persicaria expressed stronger shade-tolerance responses (increased leaf allocation and leaf area ratio) to reduced PAR alone than to green shade. By contrast, P. hydropiper expressed slightly less plasticity for these traits in neutral than in green shade. The pronounced plastic response of P. persicaria to neutral shade may contribute to the range of habitats this widespread species can occupy, which includes neutral-shade environments such as urban settings.

Adaptation, Physiological↗

PubMed2005

The effects of genotype, age, and social environment on male ornamentation, mating behavior, and attractiveness.

The traits thought to advertise genetic quality are often highly susceptible to environmental variation and prone to change with age. These factors may either undermine or reinforce the potential for advertisement traits to signal quality depending on the magnitude of age-dependent expression, environmental variation, and genotype-age and genotype-environment interaction. Measurements of the magnitude of these effects are thus a necessary step toward assessing the implications of age dependence and environmental variability for the evolution of signals of quality. We conducted a longitudinal study of male guppies (Poecilia reticulata) from 22 full-sibling families. Each fish was assigned at maturity to one of three treatments in order to manipulate his allocation of resources to reproduction: a control in which the male was kept alone, a courtship-only treatment in which he could see and court a female across a clear partition, and a mating treatment in which he interacted freely with a female. We measured each male's size, ornamental color patterns, courtship, attractiveness to females, and mating success at three ages. Size was influenced by treatment and age-treatment interactions, indicating that courtship and mating may impose costs on growth. Tail size and color patterns were influenced by age but not by treatment, suggesting fixed age-dependent trajectories in these advertisement traits. By contrast, display rate and attempted sneak copulation rate differed among treatments but not among ages, suggesting greater plasticity of these behavioral traits. As a result of the different patterns of variation in ornamentation and behavior, male attractiveness and mating success responded to male age, treatment, and the interaction between age and treatment. Neither age nor treatment obscured the presence of genetic variation, and the genetic relationship between male ornamentation and attractiveness remained the same among treatments. Our findings suggest that neither age-dependent variation nor environmentally induced variation in reproductive effort is likely to undermine the reliability of male signaling.

Age Factors↗

PubMed2006

Genetic differences between populations and habitats in Lamium purpureum plastic response to conspecific density.

Plants from Open and Shade habitats in two natural populations (Vrsac and Avala) were grown in two densities (High and Low). As expected, density had significant effect on most of measured traits and that effect was concordant with Shade avoidance syndrome predictions. Genetic differences between populations both in mean trait values and in plastic responses to density were also detected. Number of leaves and flowers showed plasticity in Avala population only, while shoot weight was plastic in both populations but with greater plasticity in Avala population. Differences between habitats for plant height and number of internodes were present in Vrsac population only. Habitat difference in response to density was revealed for seed weight and it was due to lack of response in plants originated from Shade habitat in Vrsac population. This study showed that not only populations, but also subpopulations occupying different habitats can differ genetically in their plastic response to density, and that between habitat differences can be population-specific.

Genetic Variation↗

PubMed2003

Genotype-environment interactions at quantitative trait loci affecting inflorescence development in Arabidopsis thaliana.

Phenotypic plasticity and genotype-environment interactions (GEI) play a prominent role in plant morphological diversity and in the potential functional capacities of plant life-history traits. The genetic basis of plasticity and GEI, however, is poorly understood in most organisms. In this report, inflorescence development patterns in Arabidopsis thaliana were examined under different, ecologically relevant photoperiod environments for two recombinant inbred mapping populations (Ler x Col and Cvi x Ler) using a combination of quantitative genetics and quantitative trait locus (QTL) mapping. Plasticity and GEI were regularly observed for the majority of 13 inflorescence traits. These observations can be attributable (at least partly) to variable effects of specific QTL. Pooled across traits, 12/44 (27.3%) and 32/62 (51.6%) of QTL exhibited significant QTL x environment interactions in the Ler x Col and Cvi x Ler lines, respectively. These interactions were attributable to changes in magnitude of effect of QTL more often than to changes in rank order (sign) of effect. Multiple QTL x environment interactions (in Cvi x Ler) clustered in two genomic regions on chromosomes 1 and 5, indicating a disproportionate contribution of these regions to the phenotypic patterns observed. High-resolution mapping will be necessary to distinguish between the alternative explanations of pleiotropy and tight linkage among multiple genes.

Arabidopsis↗

PubMed2005

Phenotypic plasticity of growth trajectory and ontogenic allometry in response to density for eucalyptus hybrid clones and families.

BACKGROUND: and Aims Response to density is a crucial aspect of the ecology of trees in forests and plantations. Few studies have investigated the genetics of plasticity in response to density for growth traits such as height and circumference through development. METHODS: Two experiments were carried out in the field, the first with full-sib families of Eucalyptus urophylla x E. grandis hybrids, and the second with clones of E. tereticornis x E. grandis hybrids planted across a range of densities (625, 1111 and 2500 trees ha-1). Height, circumference and stem taper were measured through development in both experiments. Variance components were estimated and a repeated measure approach for plasticity and three different methods were used to compare the variance-covariance matrix across densities. KEY RESULTS: Genetic variance was significantly different from zero but the density x genotype interaction was significant only for clone experiments at the adult stage. Significant plasticity for three traits in both experiments was found. In the clone experiments, a significant clone x time x density interaction was found, suggesting that plasticity for growth and stem form is under genetic control. In both experiments, density did not affect environmental correlation, which remained high throughout tree development. The impact of density on genetic correlation was marked in the clone experiment, with a reduced value at lower density, but was not observed in the family trial. The differences between clones and family are mainly explained by the distribution of genetic variation within and among genotypes. CONCLUSIONS: The results suggest that plasticity for growth traits and form of tropical Eucalyptus species is under genetic control and that the environment changes genetic co-variation through ontogeny. The findings confirm that a tree population with a narrow genetic basis (represented by clones) is sensitive to a changing environment, whereas a population with a broader genetic basis (full-sib family here) exhibits a more stable reaction.

Body Size↗

PubMed2005

Influence of growth environment on tolerance to UV-B radiation, germination speed, and morphology of Metarhizium anisopliae var. acridum conidia.

We previously reported wide variability in UV-B tolerance among different Metarhizium anisopliae isolates [Braga, G.U.L., Flint, S.D., Miller, C.D., Anderson, A.J., Roberts, D.W., 2001a. Variability in response to UV-B among species and strains of Metarhizium isolated from sites at latitudes from 61 degrees N to 54 degrees S. J. Invertebr. Pathol. 78, 98-108] as well as wide phenotypic variability in some of these isolates in response to alterations in their growth environments [Rangel, D.E.N., Braga, G.U.L., Flint, S.D., Anderson, A.J., Roberts, D.W., 2004. Variations in UV-B tolerance and germination speed of M. anisopliae conidia produced on artificial and natural substrates. J. Invertebr. Pathol. 87, 77-83]. Studies on other biological systems have demonstrated that strong selective pressure for tolerance to a stress factor may reduce the phenotypic variability of this trait. In the present study, conidia of the isolate most tolerant to radiation and heat, ARSEF 324, presented very little phenotypic variability in UV-B tolerance in response to production on either artificial culture medium or infected insects. The phenotypic plasticities in two other traits (conidial morphology and germination speed), however, were considerably higher.

Animals↗

PubMed1999

Dynamic phenotypic plasticity for root growth in Polygonum: a comparative study.

Species differences in patterns of phenotypic plasticity may be an important aspect of adaptive diversity. Plasticity for functionally important root traits was studied in inbred field lineages of Polygonum persicaria and P. cespitosum (Polygonaceae). Replicate seedlings were grown in plexiglass rhizotrons under a range of constant and temporally variable moisture treatments. Plasticity was determined for final whole-plant biomass, root biomass allocation, and absolute and proportional root length. The dynamic aspect of root plasticity was examined by digitizing weekly tracings of the proportional deployment of each plant's root system to different vertical soil layers. Plants of both species expressed significant functionally adaptive phenotypic plasticity in the relative allocation, length, and vertical deployment of root systems in response to contrasting moisture conditions. Plasticity patterns in these closely related species were in general qualitatively similar, but for most traits differed in the magnitude and/or the timing of the plastic response. Dynamic changes in root deployment were more marked as well as faster in P. persicaria. Species differences in patterns of individual plasticity were generally consistent with the broader ecological distribution of P. persicaria in diverse as well as temporally variable moisture habitats.

Journal Article↗

PubMed1997

Developmental phenotypic plasticity: where ecology and evolution meet molecular biology.

The plastic response of phenotypic traits to environmental change is a common research focus in several disciplines-from ecology and evolutionary biology to physiology and molecular genetics. The use of model systems such as the flowering plant Arabidopsis thaliana has facilitated a dialogue between developmental biologists asking how plasticity is controlled (proximate causes) and organismal biologists asking why plasticity exists (ultimate causes). Researchers studying ultimate causes and consequences are increasingly compelled to reject simplistic, 'black box' models, while those studying proximate causes and mechanisms are increasingly obliged to subject their interpretations to ecological 'reality checks.' We review the successful multidisciplinary efforts to understand the phytochrome-mediated shade-avoidance and light-seeking responses of flowering plants as a pertinent example of convergence between evolutionary and molecular biology. In this example, the two-way exchange between reductionist and holist camps has been essential to rapid and sustained progress. This should serve as a model for future collaborative efforts towards understanding the responses of organisms to their constantly changing environments.

Arabidopsis↗

PubMed2005

Isofemale lines in Drosophila: an empirical approach to quantitative trait analysis in natural populations.

Founding isofemale lines from wild collected females is a basic tool for investigating the genetic architecture of Drosophila natural populations. The method permits the analysis of quantitative traits under laboratory conditions, with a much broader scope than the mere evidence of a significant genetic heterogeneity among lines. Genetic variability is generally demonstrated by a significant coefficient of intraclass correlation, but several experimental precautions are needed and explained here. The relationship between classical (additive) heritability and intraclass correlation is not straightforward, presumably because the genetic bottlenecks due to the initiation of the lines unravel a significant, nonadditive genetic variance due to dominance and epistatic effects. It is thus suggested to consider intraclass correlation as a specific genetic parameter that enables comparisons between different traits, different populations or different environments. The use of isofemale lines is, however, not restricted to the calculation of an intraclass correlation. It can be used to estimate genetic correlations among traits or environments. The method is also convenient for the analysis of phenotypic plasticity in relation to an environmental gradient. A precise description of the response curves (the reaction norms) is possible, distinguishing trait parameters and plasticity parameters. A fairly general conclusion is that, for a given trait, mean value and plasticity are genetically independent. It is also possible to analyze traits, which, like sexual dimorphism, must be measured on different individuals, and even to demonstrate their genetic variability. In many cases, further empirical and theoretical analyses are possible and needed. It is argued that, in the future, isofemale lines will have an increasing significance among the various techniques appropriate to the analysis of quantitative evolutionary genetics in a diversity of species.

Animals↗

PubMed1999

Gametophytic Plasticity among Four Species of Ferns with Contrasting Ecological Distributions.

The goals of this study were to test the hypothesis that plasticity of life history traits is greater among species with broad ecological distributions than among species with narrow ecological distributions and to determine whether homosporous filicalean fern gametophytes exhibit adaptively meaningful responses to soil substrates. Sporophyte populations of Asplenium platyneuron and Polystichum acrostichoides have broader ecological distributions and were therefore expected to exhibit a greater amount of gametophytic plasticity than either Asplenium rhizophyllum or Diplazium pycnocarpon. Changes in reproductive effort (i.e., gametangia mm-2) were investigated across the four following soil treatments, which represent major edaphic environments on which sporophyte populations of these species occur: stream bank, Pinus strobus canopy, oak forest ridge top, and soil from a lime-bearing rock outcrop. Our results failed to support the "ecological breadth" hypothesis. Three of the four species-A. rhizophyllum, D. pycnocarpon, and P. acrostichoides-exhibited similar amounts and directions of plasticity, with reproductive effort greatest in treatments that were unfavorable to growth; A. platyneuron exhibited the least amount of plasticity. Nevertheless, species-specific patterns in gametophytic size and reproductive effort reflected the distributions of their sporophytic counterparts. Plasticity of size-related reproductive effort may be common among homosporous filicalean fern gametophytes because of their short life spans and limited capacity for vegetative competition.

Journal Article↗

PubMed2004

Experimental studies of adaptation in Clarkia xantiana. I. Sources of trait variation across a subspecies border.

Both genetic differentiation and phenotypic plasticity might be expected to affect the location of geographic range limits. Co-gradient variation (CoGV), plasticity that is congruent with genetic differentiation, may enhance performance at range margins, whereas its opposite, counter-gradient variation (CnGV) may hinder performance. Here we report findings of reciprocal transplant experiments intended to tease apart the roles of differentiation and plasticity in producing phenotypic variation across a geographic border between two plant subspecies. Clarkia xantiana ssp. xantiana and C. xantiana ssp. parviflora are California-endemic annuals that replace each other along a west-east gradient of declining precipitation. We analyzed variation in floral traits, phenological traits, and vegetative morphological and developmental traits by sowing seeds of 18 populations (six of ssp. xantiana and 12 of ssp. parviflora) at three sites (one in each subspecies' exclusive range and one in the subspecies' contact zone), in two growing seasons (an exceptionally wet El Niño winter and a much drier La Niña winter). Significant genetic differences between subspecies appeared in 11 of 12 traits, and differences were of the same sign as in nature. These findings are consistent with the hypothesis that selection is responsible for subspecies differences. Geographic variation within subspecies over part of the spatial gradient mirrored between-subspecies differences present at a larger scale. All traits showed significant plasticity in response to spatial and temporal environmental variation. Plasticity patterns ranged from spatial and temporal CoGV (e.g., in node of first flower), to spatial CnGV (e.g., in flowering time), to patterns that were neither CoGV nor CnGV (the majority of traits). Instances of CoGV may reflect adaptive plasticity and may serve to increase performance under year-to-year environmental variation and at sites near the subspecies border. However, the presence of spatial CnGV in some critical traits suggests that subspecies ranges may also be constrained by patterns of plasticity.

Adaptation, Biological↗

PubMed2006

The relative contributions of developmental plasticity and adult acclimation to physiological variation in the tsetse fly, Glossina pallidipes (Diptera, Glossinidae).

Recent reviews of the adaptive hypotheses for animal responses to acclimation have highlighted the importance of distinguishing between developmental and adult (non-developmental) phenotypic plasticity. There has been little work, however, on separating the effects of developmental plasticity from adult acclimation on physiological traits. Therefore, we investigated the relative contributions of these two distinct forms of plasticity to the environmental physiology of adult tsetse flies by exposing developing pupae or adult flies to different temperatures and comparing their responses. We also exposed flies to different temperatures during development and re-exposed them as adults to the same temperatures, to investigate possible cumulative effects. Critical thermal maxima were relatively inflexible in response to acclimation temperatures (21, 25, 29 degrees C) with plasticity type accounting for the majority of the variation (49-67%, nested ANOVA). By contrast, acclimation had a larger effect on critical thermal minima with treatment temperature accounting for most of the variance (84-92%). Surprisingly little of the variance in desiccation rate could be explained by plasticity type (30-47%). The only significant effect of acclimation temperature on standard (resting) metabolic rate of adult flies was at 21 degrees C, resulting in treatment temperature, rather than plasticity type, accounting for the majority of the variance (30-76%). This study demonstrates that the stage at which acclimation takes place has significant, though often different, effects on several adult physiological traits in G. pallidipes, and therefore that it is not only important to consider the form of plasticity but also the direction of the response and its significance from a life-history perspective.

Acclimatization↗

PubMed1998

A proposal for a new direction to treat cancer.

A new approach is proposed that has the potential to be a successful therapy for most disseminated cancers because it can circumvent the problems posed by three characteristics which are universally expressed by cancer cells: heterogeneity, plasticity, and the lack of a cancer specific or cancer associated characteristic which is not also shared by some normal cells. Analysis shows that almost all current and research approaches for treating disseminated cancers have the same fundamental strategy: they rely on an agent interacting individually and effectively with each cancer cell. We call all these approaches "lock and key" strategies to emphasize the need for this individual agent to cell interaction. The three characteristics preclude current approaches from successfully treating most disseminated cancers because they operate by a "lock and key" strategy which (a) only kills cancer cells expressing a single particular trait, (b) allows other cancer cells to adapt and survive the treatment, and (c) also kills the normal cells which express the same particular trait. The heterogeneity and plasticity of cancer cells can only be circumvented by an attack which is microregional (not cell by cell) and destructive (not killed by conventional endogenous or exogenous cytotoxic agents). All cells in each microregion must be destroyed, including those which do not express an exploitable trait. The proposed approach can achieve such microregional destruction by the delivery to, and long term immobilization of, a large number of radio-isotopes. The proposed approach exploits the additive contribution of multiple mechanisms to enhance tumor specificity of the microregions. Given that all targeting and killing agents are "imperfect", this is the only way specificity can be enhanced. The biological basis of these specificity enhancing mechanisms are well-known. However, they are ignored by current therapies because most of them can only be exploited in the context of the proposed approach. Some of the mechanisms reflect characteristics, such as heterogeneity, genetic instability, and tumor progression which are the result of the micro-evolutionary process of tumor development. These are virtually always present in, and virtually specific to, cancer. Others reflect the somewhat "imperfect" cancer associated characteristics of structures, including cancer cells, extracellular structures, and non-malignant cells within the tumor mass. The additive contribution of the multiple mechanisms gives the process the potential to destroy all the cancer cells with minimal non-tumor toxicity. The cornerstone of the proposed approach is a novel class of soluble chemicals. They can be administered intravenously to subjects, circulate throughout body fluids and are enzymatically converted into an insoluble material when the chemicals reach targeted sites. In this paper, these chemicals are called "soluble precipitable reagents" (SPR) to describe their ability to be converted from a soluble to an insoluble material. The insoluble material is called platform to indicate that it has the ability to bind various agents. The SPR chemicals enable a three-step process to be constructed which can deliver and retain a large number of radio-isotope atoms in tumor tissue. In step 1, a binary reagent comprised of an SPR attached to an imperfect cancer targeting agent is administered. The binary reagent is endocytosed and transported into lysosomes where the targeting agent moiety is digested and the detached SPR is converted by natural intracellular lysosomal enzymes into a platform. As will be discussed, a very large number of platform molecules can be made to accumulate inside targeted cells. In step 2, a supersensitive fraction of the cancer cells, including some which had accumulated platform in step 1, are killed by the administration of a very low dose of an anti-cancer agent. Very few, if any, normal cells will be killed by the very low dose. The death of the ce

Humans↗

PubMed2002

Phenotypic plasticity and integration in response to flooded conditions in natural accessions of Arabidopsis thaliana (L.) Heynh (Brassicaceae).

Flood response is a crucial component of the life strategy of many plants, but it is seldom studied in non-flooded tolerant species, even though they may be subjected to stressful environmental conditions. Phenotypic plasticity in reaction to environmental stress affects the whole plant phenotype and can alter the character correlations that constitute the phenotypic architecture of the individual, yet few studies have investigated the lability of phenotypic integration to water regime. Moreover, little has been done to date to quantify the sort of selective pressures that different components of a plant's phenotype may be experiencing under contrasting water regimes. Genetic differentiation and phenotypic plasticity at the single-trait and multivariate levels were investigated in 47 accessions of the weedy plant Arabidopsis thaliana, and the relationship of plastic characters to reproductive fitness was quantified. Results indicate that these plants tend to be highly genetically differentiated for all traits, in agreement with predictions made on the basis of environmental variation and mating system. Varied patterns of apparent selection under flooded and non-flooded conditions were also uncovered, suggesting trade-offs in allocation between roots and above-ground biomass, as well as between leaves and reproductive structures. While the major components of the plants' multivariate phenotypic architecture were not significantly affected by environmental changes, many of the details were different under flooded and non-flooded conditions.

Acclimatization↗

PubMed2005

Phenotypic plasticity in the developmental integration of morphological trade-offs and secondary sexual trait compensation.

Trait exaggeration through sexual selection will tale place alongside other changes in phenotype. Exaggerated morphology might be compensated by parallel changes in traits that support, enhance or facilitate exaggeration: 'secondary sexual trait compensation' (SSTC). Alternatively, exaggeration might be realized at the expense of other traits through morphological trade-offs. For the most part, SSTC has only been examined interspecifically. For these phenomena to be important intraspecifically, the sexual trait must be developmentally integrated with the compensatory or competing trait. We studied developmental integration in two species with different development: the holometabolous beetle Onthophagus taurus and the hemimetabolous earwig Forficula auricularia. Male-dimorphic variation in trait exaggeration was exploited to expose both trade-offs and SSTC. We found evidence for morphological trade-offs in O. taurus, but no F. auricularia, supporting the notion that trade-offs are more likely in closed developmetal systems. However, we found these trade-offs were not limited solely to traits growing close together. Developmental integration of structures involved in SSTC were detected in both species. The developmental integration of SSTC was phenotypically plastic, such that the compensation for relatively larger sexual traits was greater in the exasperated male morphs. Evidence of intraspecific SSTC demands studies of the selective, genetic and developmental architecture of phenotypic integration.

Animals↗