On the fate of seasonally plastic traits in a rainforest butterfly under relaxed selection
Oostra, V. ; Brakefield, P.M. ; Hiltemann, Y. ; Zwaan, B.J. ; Brattström, O. - \ 2014
Ecology and Evolution 4 (2014)13. - ISSN 2045-7758 - p. 2654 - 2667.
sexual size dimorphism - bicyclus-anynana - phenotypic plasticity - reaction norms - life-history - evolutionary significance - artificial selection - geographic-variation - resource-allocation - thermal plasticity
Many organisms display phenotypic plasticity as adaptation to seasonal environmental fluctuations. Often, such seasonal responses entails plasticity of a whole suite of morphological and life-history traits that together contribute to the adaptive phenotypes in the alternative environments. While phenotypic plasticity in general is a well-studied phenomenon, little is known about the evolutionary fate of plastic responses if natural selection on plasticity is relaxed. Here, we study whether the presumed ancestral seasonal plasticity of the rainforest butterfly Bicyclus sanaos (Fabricius, 1793) is still retained despite the fact that this species inhabits an environmentally stable habitat. Being exposed to an atypical range of temperatures in the laboratory revealed hidden reaction norms for several traits, including wing pattern. In contrast, reproductive body allocation has lost the plastic response. In the savannah butterfly, B. anynana (Butler, 1879), these traits show strong developmental plasticity as an adaptation to the contrasting environments of its seasonal habitat and they are coordinated via a common developmental hormonal system. Our results for B. sanaos indicate that such integration of plastic traits – as a result of past selection on expressing a coordinated environmental response – can be broken when the optimal reaction norms for those traits diverge in a new environment
Spatial variation in growth, maturation schedules and reproductive investment of female sole solea solea in the Northeast AtlanTic
Mollet, F.M. ; Engelhard, G.H. ; Vainikka, A. ; Laugen, A.T. ; Rijnsdorp, A.D. ; Ernande, B. - \ 2013
Journal of Sea Research 84 (2013). - ISSN 1385-1101 - p. 109 - 121.
cod gadus-morhua - plaice pleuronectes-platessa - herring clupea-harengus - long-term changes - countergradient variation - reaction norms - bergmanns rule - rana-temporaria - sea plaice - evolutionary significance
Latitudinal variation in life-history traits is often explained by phenotypically plastic responses or local adaptations to different thermal regimes. We compared growth, maturation schedules and reproductive investment of female sole Solea solea between 8 populations, covering much of the species' distribution in northern Europe, with respect to thermal gradients. An energy allocation model was fitted to size–age data, and probabilistic maturation reaction norms were estimated from size–age–maturity data. We found that northern populations from colder environments had higher rates of energy acquisition and reproductive investment, an intrinsic tendency to mature earlier, and had smaller asymptotic sizes than southern populations from warmer environments. Consequently, growth rate was higher before maturation but lower after maturation in the north compared to the south. This is opposite to Bergmann's rule according to which slower growth, delayed maturation and larger asymptotic sizes are usually observed at lower temperatures. The observed patterns could indicate strong countergradient thermal adaptation for rapid growth and development as well as sustained fecundity in the north, or indicate a response to other selection pressures correlated with the thermal gradient. Potentially higher mortality in northern populations during cold winters might be one of the key drivers of the observed geographical variation in growth and maturation of sole.
Metabolomics: the chemistry between ecology and genetics
Macel, M. ; Dam, N.M. van; Keurentjes, J.J.B. - \ 2010
Molecular Ecology Resources 10 (2010). - ISSN 1755-098X - p. 583 - 593.
plant-herbivore interactions - arabidopsis-thaliana - pyrrolizidine alkaloids - mass-spectrometry - secondary metabolites - functional genomics - evolutionary significance - cynoglossum-officinale - generalist herbivores - quantitative trait
Metabolomics is a fast developing field of comprehensive untargeted chemical analyses. It has many applications and can in principle be used on any organism without prior knowledge of the metabolome or genome. The amount of functional information that is acquired with metabolomics largely depends on whether a metabolome database has been developed for the focal species. Metabolomics is a level downstream from transcriptomics and proteomics and has been widely advertised as a functional genomics and systems biology tool. Indeed, it has been successfully applied to link phenotypes to genotypes in the model plant Arabidopsis thaliana. Metabolomics is also increasingly being used in ecology (ecological metabolomics) and environmental sciences (environmental metabolomics). In ecology, the technique has led to novel insights into the mechanisms of plant resistance to herbivores. Some of the most commonly used analytical metabolomic platforms are briefly discussed in this review, as well as their limitations. We will mainly focus on the application of metabolomics in plant ecology and genetics
Sibling competition, size variation and frequency-dependent outcrossing advantage in Plantago coronopus
Koelewijn, H.P. - \ 2004
Evolutionary Ecology 18 (2004)1. - ISSN 0269-7653 - p. 51 - 74.
restricted gene flow - inbreeding depression - impatiens-capensis - evolutionary significance - sexual reproduction - sib-competition - self-fertilization - mating systems - male-sterility - kin selection
Many plants display limited seed dispersal, thereby creating an opportunity for sibling competition, i.e. fitness-determined interactions between related individuals. Here I investigated the consequences of intra-specific competition, by varying density and genetic composition of neighbors, on the performance of seedlings derived by selfing or outcrossing of the partially self-fertilizing plant Plantago coronopus (L.). Seedlings from eight plants, randomly selected from an area of about 50 m2 in a natural population, were used in (i) a density series with either one, four or eight siblings of each cross type per pot and (ii) a replacement series with eight plants per pot where selfed and outcrossed siblings were grown intermixed in varying frequencies. Density had a pronounced effect on plant performance. But, except for singly grown individuals, no differences were detected between selfed and outcrossed progenies in vegetative and reproductive biomass. When grown intermixed, selfed offspring were always inferior to their outcrossed relatives. The magnitude of reduction in performance was dependent on the number of outcrossed relatives a selfed seedling had to compete with, giving rise to a frequency-dependent fitness advantage to outcrossed seedlings. The major result of this study is (i) that the relative fitness of inbred progeny is strongly affected by the type of competitors (inbred or outbred) and (ii) that inbreeding depression varies according to the density and frequency of outbred plants and could be considered as a density- and frequency-dependent phenomenon. It is argued that sibling competition, due to the small genetic neighborhood of P. coronopus, might be an important selective force in natural populations of this species.