共查询到20条相似文献，搜索用时 10 毫秒
1.
Donohue K Pyle EH Messiqua D Heschel MS Schmitt J 《Evolution; international journal of organic evolution》2001,55(4):692-702
We tested for adaptive differentiation between two natural populations of Impatiens capensis from sites known to differ in selection on plasticity to density. We also determined the degree to which plasticity to density within a site was correlated with plastic responses of experimental immigrants to foreign sites. Inbred lines, derived from natural populations in an open-canopy site and a woodland site, were planted reciprocally in both original sites at naturally occurring high densities and at low density. The density manipulation represents environmental variation typically experienced within the site of a given population, and the transplant manipulation represents environmental differences between sites of different populations. Internode elongation, meristem allocation, leaf length, flowering date, and total lifetime fitness were measured. Genotypes originating in the open site, where selection favored plasticity of first internode length and flowering time (Donohue et al. 2000a), were more plastic in those characters than genotypes originating from the woodland site, where plasticity was maladaptive. Therefore, these two populations appear to have responded to divergent selection on plasticity. Plasticity to density strongly resembled plasticity to site differences for many characters, suggesting that similar environmental factors elicit plasticity both to density and to overhead canopy. Thus, plasticity that evolved in response to density variation within a site influenced phenotypic expression in the foreign site. Plastic responses to site caused immigrants from foreign populations to resemble native genotypes more closely. In particular, immigrants from the open site converged toward the selectively favored early-flowering phenotype of native genotypes in the woodland site, thereby reducing potential fitness differences between foreign and native genotypes. However, because genotypes from the woods population were less plastic than genotypes from the sun population, phenotypic differences between populations were greatest in the open site at low density. Therefore, population differences in plasticity can cause genotypes from foreign populations to be more strongly selected against in some environments than in others. However, genetic constraints and limits to plasticity prevented complete convergence of immigrants to the native phenotype in any environment. 相似文献
2.
Fiona J. Qualls Richard Shine 《Biological journal of the Linnean Society. Linnean Society of London》1998,64(4):477-491
Geographic variation in phenotypes can result from proximate environmental effects as well as from underlying genetic factors. Reciprocal transplant experiments, in which organisms are moved from one area to another, offer a powerful technique to partition the effects of these two factors. However, many studies that have utilized this technique have focused on the post-hatching organism only and ignored potential effects of environmental influences acting during embryonic development. We examined the phenotypic responses of hatchling scincid lizards ( Lampropholis guichenoti ) incubated in the laboratory under thermal regimes characteristic of natural nests in two study areas in southeastern Australia. Although the sites were less than 120 km apart, lizards from these two areas differed in thermal regimes of natural nests, and in hatchling phenotypes (morphology, locomotor performance). We incubated eggs from each area under the thermal regimes typical of both sites. Some of the traits we measured (e.g. hatchling mass and snout-vent length) showed little or no phenotypic plasticity in response to differences in incubation conditions, whereas other traits (e.g. incubation period, tail length, inter-limb length, body shape, locomotor performance) were strongly influenced by the thermal regime experienced by the embryo. Thus, a significant proportion of the geographic variation in morphology and locomotor performance of hatchling lizards may be directly induced by differences in nest temperatures rather than by genetic divergence. We suggest that future studies using the reciprocal transplant design should consider environmental influences on all stages of the life-history, including embryonic development as well as post-hatching life. 相似文献
3.
FIONA J. QUALLS RICHARD SHINE 《Biological journal of the Linnean Society. Linnean Society of London》2000,71(2):315-341
While recent experimental work on a variety of reptile species has demonstrated that incubation temperature influences hatchling phenotypes, the biological significance of such phenotypic variation remains unclear. Incubation temperature may exert significant long-term phenotypic effects. Alternatively, such influences may be temporary, or negligible relative to effects induced by genetic factors, or by the environmental conditions experienced after hatching. Even if incubation temperature exerts long-term effects on phenotype, this might occur indirectly (by influencing hatching dates) rather than by direct modifications of developmental processes. We quantified the influences of the source population, incubation temperature and rearing environment, on the phenotype of the Australian garden skink (Lampropholis guichenoti) from populations that differ in nest temperature and phenotype. Intcrpopulation differences in the phenotypes of young lizards were found to be a product of all three factors. However, the long-term effects of both population and incubation temperature operated indirectly (through variation in the date of hatching) rather than directly (through genetic or developmental factors). That is, once all temporal effects were removed, the only discernible influence on juvenile phenotypes was their rearing environment. Thus, some of the most important influences on lizard phenotypes may operate via modifications of hatching date. 相似文献
4.
不同地理种源紫茎泽兰的生态适应性比较 总被引：2，自引：0，他引：2
采用交互移植法,对移栽在6种不同生境中的5个不同种源紫茎泽兰幼苗的存活率、株高、分枝数、生物量、单株花序数、产种量和种子萌发率进行了为期1年的对比研究.结果表明：各种源紫茎泽兰的幼苗生长和繁殖特性对样地环境条件变化均表现出很强的可塑性.试验样地因素对幼苗株高、分枝数、生物量、单株花序数和产种量的影响均达到极显著水平(P＜0.001).随着样地纬度和海拔的升高,各种源的幼苗株高、分枝数量、单株生物量、每株花序数量和单株产种量均呈下降趋势,且各样地间的差异均达到显著水平(P＜0.05).但种源因素对幼苗株高、分枝数、生物量、单株花序数和产种量的影响均不显著（P＞0.05）.除单株产种量外,种源与试验样地的交互作用对上述各指标的影响均不显著.在各样地内,当地种源幼苗的存活率、生长能力和繁殖能力均未表现出显著的优势.说明紫茎泽兰在我国西南地区入侵成功主要依靠其较高的表型可塑性,而局域适应的作用相对较小. 相似文献
5.
Lukas Widmer Adrian Indermaur Bernd Egger Walter Salzburger 《Ecology and evolution》2020,10(17):9410-9418
Food resource specialization within novel environments is considered a common axis of diversification in adaptive radiations. Feeding specializations are often coupled with striking morphological adaptations and exemplify the relation between morphology and diet (phenotype–environment correlations), as seen in, for example, Darwin finches, Hawaiian spiders, and the cichlid fish radiations in East African lakes. The cichlids' potential to rapidly exploit and occupy a variety of different habitats has previously been attributed to the variability and adaptability of their trophic structures including the pharyngeal jaw apparatus. Here we report a reciprocal transplant experiment designed to explore the adaptability of the trophic structures in highly specialized cichlid fish species. More specifically, we forced two common but ecologically distinct cichlid species from Lake Tanganyika, Tropheus moorii (rock‐dweller), and Xenotilapia boulengeri (sand‐dweller), to live on their preferred as well as on an unpreferred habitat (sand and rock, respectively). We measured their overall performance on the different habitat types and explored whether adaptive phenotypic plasticity is involved in adaptation. We found that, while habitat had no effect on the performance of X. boulengeri, T. moorii performed significantly better in its preferred habitat. Despite an experimental duration of several months, we did not find a shift in the morphology of the lower pharyngeal jaw bone that would be indicative of adaptive phenotypic plasticity in this trait. 相似文献
6.
Ecotype differentiation and coexistence of two parapatric tetraploid subspecies of cocksfoot (Dactylis glomerata) in the Alps 总被引：2，自引：0，他引：2
Two tetraploid subspecies of Dactylis glomerata L., subsp. reichenbachii (Hausm.) Stebbins et Zohary and subsp. glomerata , occur in the French Alps. The former is confined to dolomitic, south-facing, alpine lawns above 2000 m, whereas the latter occurs in non-dolomitic habitats in subalpine meadows mainly below 1900 m. Previous studies of allozyme variation have shown that genetic introgression between the two subspecies occurs over large areas. By contrast, morphologically intermediate individuals only occur in an extremely narrow area, suggesting that the morphological and physiological differences between the two subspecies is of adaptive significance. A reciprocal clone transplant experiment was set up to examine (1) any genetic differences between subspecies indicative of ecotypic differentiation in relation to habitat characteristics and (2) the level of phenotypic plasticity in the two subspecies. Genetic differentiation was confirmed by a statistically significant taxon × site interaction effect in anova for all traits studied. The glomerata populations produced more tillers, longer leaves and higher culms in all sites, especially in their home environment. However, reichenbachii populations produced more seeds than the glomerata populations in the original reichenbachii environment, suggesting ecotypic differentiation between the two subspecies. This result might also explain why the glomerata subspecies is unable to colonize dolomitic habitats occupied by the reichenbachii subspecies. The reichenbachii populations showed less plasticity than the glomerata populations for leaf length and floriferous tiller number, a result which is discussed in the context of the response of plants from productive and non-productive habitats to environmental variation. 相似文献
7.
Genetic variation and phenotypic plasticity in a trophically polymorphic population of pumpkinseed sunfish (Lepomis gibbosus) 总被引：5，自引：0，他引：5
Summary Adaptive variation can exist at a variety of scales in biological systems, including among species, among local populations of a single species and among individuals within a single population. Trophic or resource polymorphisms in fishes are a good example of the lowest level of this hierarchy. In lakes without bluegill sunfish (Lepomis macrochirus), pumpkinseed sunfish (Lepomis gibbosus) can be trophically polymorphic, including a planktivorous limnetic form found in the pelagic habitat, in addition to the usual benthic form found in the littoral zone. In this paper we examine the degree to which morphological differences between the two forms are caused by genetic differences versus phenotypic plasticity. Adults from pelagic and littoral sites in Paradox Lake, NY, were bred separately and their progeny were raised in cages both in the open water and shallow water habitats of an artificial pond. The experimental design permitted two tests of genetic differences between the breeding stocks (in open and shallow water cages, respectively) and two tests of phenotypic plasticity (in the limnetic and benthic offspring, respectively). Limnetic progeny were more fusiform than benthic progeny raised in the same habitat. In addition, progeny of both stocks displayed limnetic-type characteristics when raised in the open water and benthic-type characteristics in the shallow water. Thus, genetic differences and phenotypic plasticity both contributed to the trophic polymorphism. Phenotypic plasticity and genetic differentiation accounted for 53 and 14%, respectively, of the variation in morphology. This study addresses the nature of subtle phenotypic differences among individuals from a single population that is embedded within a complex community, a condition that is likely to be the norm for most natural populations, as opposed to very large differences that have evolved in relatively few populations that reside in species-poor environments. 相似文献
8.
James D. Fry Stefanie L. Heinsohn Trudy F. C. Mackay 《Evolution; international journal of organic evolution》1996,50(6):2316-2327
Many studies have documented the existence of genotype-environment interaction (GEI) for traits closely related to fitness in natural populations. A type of GEI that is commonly observed is changes in the fitness ranking of genetic groups (families, clones, or inbred lines) in different environments. We refer to such changes in ranking as crossing of reaction norms for fitness. A common interpretation of crossing of reaction norms for fitness is that selection favors different alleles in the different environments (i.e., that “trade-offs” exist). If this is the case, selection could maintain genetic variation, and even lead to reproductive isolation between subpopulations using different environments. Even if the same alleles are favored in every environment, however, deleterious mutations that vary in the magnitude of their effect depending on environment could cause reaction norms for fitness to cross. If deleterious mutations with environment-dependent effects are responsible for maintaining much of the variation leading to crossing of reaction norms for fitness in natural populations, it should be possible to observe crossing of reaction norms for fitness among otherwise genetically identical lines bearing newly arisen spontaneous mutations. We examined the contribution of new mutations to GEI for fitness in Drosophila melanogaster. Eighteen lines were derived from a common, highly inbred base stock, and maintained at a population size of 10 pairs for over 200 generations, to allow them to accumulate spontaneous mutations. Because of the small population size of the lines, selection against mildly deleterious mutations should have been relatively ineffective. The lines were tested for productivity (number of surviving adult progeny from a standard number of parents) in five different environmental treatments, comprising different food media, temperatures, and levels of competition. The lines showed highly significant GEI for productivity, owing largely to considerable changes in ranking in the different environments. We conclude that mutations that are deleterious on average, but whose quantitative effects depend on environment, could be responsible for maintaining much of the variation leading to crossing of reaction norms for fitness that has been observed in samples of D. melanogaster from the wild. 相似文献
9.
Byars SG Papst W Hoffmann AA 《Evolution; international journal of organic evolution》2007,61(12):2925-2941
Alpine environments are particularly susceptible to environmental changes associated with global warming but there is potential for alpine plants to adapt to warming if local adaptation occurs and gene flow allows genotypes adapted to low altitudes to colonize higher altitude sites. Here we examine the adaptive potential of a common alpine grass, Poa hiemata, within the restricted alpine habitat of Australian mountains, across a narrow altitudinal gradient replicated in three areas. Grasses at high altitude sites had shorter leaf lengths and larger circumferences than those at lower sites. Transplant experiments with clonal material and plants grown from seed indicated that these differences were partly genetic, with environmental and genetic factors both contributing to the differences between altitudes. Differences in altitudinal forms were also evident in a common garden experiment. Plants showed a home-site advantage in terms of survival. A fitness analysis indicated that at high altitude sites, selection favored plants with short leaves and larger circumferences, whereas these traits were selected in the opposite direction at the low altitude sites. These findings indicate cogradient selection and potential for both plastic and genotypic shifts in response to climate change in P. hiemata. 相似文献
10.
11.
Taylor M. Crow Jenn M. Yost Michelle S. Huang Matthew K. Ritter 《American journal of botany》2019,106(5):704-712
12.
D. J. BARSHIS J. H. STILLMAN R. D. GATES R. J. TOONEN L. W. SMITH C. BIRKELAND 《Molecular ecology》2010,19(8):1705-1720
The degree to which coral reef ecosystems will be impacted by global climate change depends on regional and local differences in corals’ susceptibility and resilience to environmental stressors. Here, we present data from a reciprocal transplant experiment using the common reef building coral Porites lobata between a highly fluctuating back reef environment that reaches stressful daily extremes, and a more stable, neighbouring forereef. Protein biomarker analyses assessing physiological contributions to stress resistance showed evidence for both fixed and environmental influence on biomarker response. Fixed influences were strongest for ubiquitin‐conjugated proteins with consistently higher levels found in back reef source colonies both pre and post‐transplant when compared with their forereef conspecifics. Additionally, genetic comparisons of back reef and forereef populations revealed significant population structure of both the nuclear ribosomal and mitochondrial genomes of the coral host (FST = 0.146 P < 0.0001, FST = 0.335 P < 0.0001 for rDNA and mtDNA, respectively), whereas algal endosymbiont populations were genetically indistinguishable between the two sites. We propose that the genotype of the coral host may drive limitations to the physiological responses of these corals when faced with new environmental conditions. This result is important in understanding genotypic and environmental interactions in the coral algal symbiosis and how corals may respond to future environmental changes. 相似文献
13.
Martin Eriksson Alexandra Kinnby Pierre De Wit Marina Rafajlović 《Evolutionary Applications》2023,16(2):486-503
Adaptive phenotypic plasticity may improve the response of individuals when faced with new environmental conditions. Typically, empirical evidence for plasticity is based on phenotypic reaction norms obtained in reciprocal transplant experiments. In such experiments, individuals from their native environment are transplanted into a different environment, and a number of trait values, potentially implicated in individuals' response to the new environment, are measured. However, the interpretations of reaction norms may differ depending on the nature of the assessed traits, which may not be known beforehand. For example, for traits that contribute to local adaptation, adaptive plasticity implies nonzero slopes of reaction norms. By contrast, for traits that are correlated to fitness, high tolerance to different environments (possibly due to adaptive plasticity in traits that contribute to adaptation) may, instead, result in flat reaction norms. Here we investigate reaction norms for adaptive versus fitness-correlated traits and how they may affect the conclusions regarding the contribution of plasticity. To this end, we first simulate range expansion along an environmental gradient where plasticity evolves to different values locally and then perform reciprocal transplant experiments in silico. We show that reaction norms alone cannot inform us whether the assessed trait exhibits locally adaptive, maladaptive, neutral, or no plasticity, without any additional knowledge of the traits assessed and species' biology. We use the insights from the model to analyse and interpret empirical data from reciprocal transplant experiments involving the marine isopod Idotea balthica sampled from two geographical locations with different salinities, concluding that the low-salinity population likely has reduced adaptive plasticity relative to the high-salinity population. Overall, we conclude that, when interpreting results from reciprocal transplant experiments, it is necessary to consider whether traits assessed are locally adaptive with respect to the environmental variable accounted for in the experiments or correlated to fitness. 相似文献
14.
Plant populations may show differentiation in phenotypic plasticity, and theory predicts that greater levels of environmental
heterogeneity should select for higher magnitudes of phenotypic plasticity. We evaluated phenotypic responses to reduced soil
moisture in plants of Convolvulus chilensis grown in a greenhouse from seeds collected in three natural populations that differ in environmental heterogeneity (precipitation
regime). Among several morphological and ecophysiological traits evaluated, only four traits showed differentiation among
populations in plasticity to soil moisture: leaf area, leaf shape, leaf area ratio (LAR), and foliar trichome density. In
all of these traits plasticity to drought was greatest in plants from the population with the highest interannual variation
in precipitation. We further tested the adaptive nature of these plastic responses by evaluating the relationship between
phenotypic traits and total biomass, as a proxy for plant fitness, in the low water environment. Foliar trichome density appears
to be the only trait that shows adaptive patterns of plasticity to drought. Plants from populations showing plasticity had
higher trichome density when growing in soils with reduced moisture, and foliar trichome density was positively associated
with total biomass.
Co-ordinating editor: F. Stuefer 相似文献
15.
FRANCIS STROBBE ROBBY STOKS 《Biological journal of the Linnean Society. Linnean Society of London》2004,83(2):187-196
Optimality models predict that, under a time constraint, organisms should accelerate development, and preferably so by increasing growth rate, to keep size at emergence constant. Unfortunately, most tests did neglect genetic constraints and interchanged mass with body size which may explain mixed support for some of the models' predictions. We imposed time constraints on full sibling larvae of the damselfly Enallagma cyathigerum by manipulating day length regimes. Under a time constraint, larval development and growth rate based on size indeed were faster. This made it possible to keep size at emergence constant, despite the shorter development time. Interestingly, under a time constraint, growth rate based on mass was not increased and larvae had a lower mass at emergence. We see two reasons for this difference between body mass and size. First, size is fixed at emergence, while mass can still increase in many insects. Secondly, genetic constraints may have contributed to different responses for size and mass. In general, our results strongly suggest discriminating between size and mass when testing life history responses. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 83 , 187–196. 相似文献
16.
Karban R 《Ecology letters》2008,11(7):727-739
Plant behaviours are defined as rapid morphological or physiological responses to events, relative to the lifetime of an individual. Since Darwin, biologists have been aware that plants behave but it has been an underappreciated phenomenon. The best studied plant behaviours involve foraging for light, nutrients, and water by placing organs where they can most efficiently harvest these resources. Plants also adjust many reproductive and defensive traits in response to environmental heterogeneity in space and time. Many plant behaviours rely on iterative active meristems that allow plants to rapidly transform into many different forms. Because of this modular construction, many plant responses are localized although the degree of integration within whole plants is not well understood. Plant behaviours have been characterized as simpler than those of animals. Recent findings challenge this notion by revealing high levels of sophistication previously thought to be within the sole domain of animal behaviour. Plants anticipate future conditions by accurately perceiving and responding to reliable environmental cues. Plants exhibit memory, altering their behaviours depending upon their previous experiences or the experiences of their parents. Plants communicate with other plants, herbivores and mutualists. They emit cues that cause predictable reactions in other organisms and respond to such cues themselves. Plants exhibit many of the same behaviours as animals even though they lack central nervous systems. Both plants and animals have faced spatially and temporally heterogeneous environments and both have evolved plastic response systems. 相似文献
17.
18.
Daniel B. Schwab Armin P. Moczek 《Proceedings. Biological sciences / The Royal Society》2014,281(1793)
Resource allocation trade-offs arise when developing organs are in competition for a limited pool of resources to sustain growth and differentiation. Such competition may constrain the maximal size to which structures can grow and may force a situation in which the evolutionary elaboration of one structure may only be possible at the expense of another. However, recent studies have called into question both the consistency and evolutionary importance of resource allocation trade-offs. This study focuses on a well-described trade-off between the horns and eyes of Onthophagus beetles and assesses the degree to which it is influenced by genetic, developmental and ecological conditions. Contrary to expectations, we observed that trade-off signatures (i) were mostly absent within natural populations, (ii) mostly failed to match naturally evolved divergences in horn investment among populations, (iii) were subject to differential changes in F1 populations derived from divergent field populations and (iv) remained largely unaffected by developmental genetic manipulations of horn investment. Collectively, our results demonstrate that populations subject to different ecological conditions exhibit different patterns of, and differential plasticity in, resource allocation. Further, variation in ecological conditions, rather than canalized developmental mechanisms, may determine whether and to what degree morphological structures engage in resource allocation trade-offs. 相似文献
19.
Weinig C 《Evolution; international journal of organic evolution》2000,54(1):124-136
Under competitive conditions, stem elongation in plants is thought to enhance fitness by increasing light interception. However, the onset of competition should vary with the species of competitor due to interspecific differences in timing of emergence and plant growth form. The fitness benefits of elongation may therefore depend on the timing of this plastic response. Phenotypic selection analyses and path analysis were used to evaluate selection acting on stem elongation at early and late life-history stages and the combination of germination timing and elongation in an annual plant. Velvetleaf (Abutilon theophrasti) were raised in one of three environments experienced by natural populations (cornfields; soybean fields; and disturbed, weedy sites). Due to the rapid growth rate and high density of plants in disturbed areas, selection to increase seedling-stage elongation was expected in weedy sites. Due to the wide spacing of crop plants, competition for light is initially low in cultivated fields, but intensifies as the season progresses. Selection for increased elongation at later nodes was expected in soybean fields because velvetleaf can often overtop soy and thereby increase leaf exposure. In contrast, selection against late elongation was expected in cornfields because velvetleaf are incapable of overtopping corn. Individuals that elongate would experience the carbon cost of allocating to structural tissue, but fail to experience a carbon return through increased light interception. The phenotypic selection analyses were consistent with these predictions and therefore support the role of stem elongation as an adaptation to interspecific competition. Selection also acted on the combination of germination timing and elongation. In the weedy environment, early emergence in conjunction with enhanced stem elongation conveyed the highest fitness. Reduced elongation was favored among individuals that emerged late, potentially because these individuals were unable to overtop neighbors. The results of this study demonstrate that the timing of stem elongation strongly affects competitive success. Environments that differ in the timing of competition for light select for elongation at different life-history stages, and this selection depends on the timing of emergence. 相似文献
20.
Lorenzon P Clobert J Massot M 《Evolution; international journal of organic evolution》2001,55(2):392-404
Correlation between intraspecific phenotypic variability and variation of environmental conditions could reflect adaptation. Different phenotypes may result from differential expression of a genotype in different environments (phenotypic plasticity) or from expression of different genotypes (genetic diversity). Populations of Lacerta vivipara exhibit larger adult body length, lower age at maturity, higher fecundity, and smaller neonatal size in humid habitats compared to dry habitats. We conducted reciprocal transplants of juvenile L. vivipara to test for the genetic or plastic origin of this variation. We captured gravid females from four populations that differed in the relative humidity of their habitats, and during the last 2 to 4 weeks of gestation, we manipulated heat and water availability under laboratory conditions. Juveniles were released into the different populations and families were divided to compare growth rate and survival of half-sibs in two environments. Growth rate and survival were assessed using capture-recapture techniques. Growth rate was plastic in response to postnatal conditions and did not differ between populations of origin. Survival differed between populations of origin, partially because of differences in neonatal body length. The response of juvenile body length and body condition to selection in the different habitats was affected by the population of origin. This result cannot be simply interpreted in terms of adaptation; however, phenotypic plasticity of fecundity or juvenile size most probably resulted in adaptive reproductive strategies. Adaptation to the habitat by means of genetic specialization was not detected. Further investigation is needed to discriminate between genetic and long-term maternal effects. 相似文献