Search results for "evolutionary"
showing 10 items of 4392 documents
Trajectoires ontogénétiques et hétérochronies complexeschez des ammonites (Harpoceratinae) du Jurassique inférieur (Domérien)
1989
Evolutive transformations of ontogeny in the two main groups of Harpoceratinae which colonize the North-West Europe during the lower Domerian — Protogrammoceras (Matteiceras) and Protogrammoceras (Fieldingiceras) — are analyzed. Within P. (Matteiceras) these transformations belong to a strict heterochronical logic (translation of a standard ontogenetic trajectory). Within P. (Fieldingiceras) the alterations of the ontogeny cannot be placed in a same logic. Moreover, the P. (Matteiceras) heterochronical issues are complex: paedomorphic (neoteny) and peramorphic (acceleration) tendencies appear on both sides of critical point (inversion point) for a same feature, the ribs density.
An enhanced memetic differential evolution in filter design for defect detection in paper production.
2008
This article proposes an Enhanced Memetic Differential Evolution (EMDE) for designing digital filters which aim at detecting defects of the paper produced during an industrial process. Defect detection is handled by means of two Gabor filters and their design is performed by the EMDE. The EMDE is a novel adaptive evolutionary algorithm which combines the powerful explorative features of Differential Evolution with the exploitative features of three local search algorithms employing different pivot rules and neighborhood generating functions. These local search algorithms are the Hooke Jeeves Algorithm, a Stochastic Local Search, and Simulated Annealing. The local search algorithms are adap…
Platyzoan paraphyly based on phylogenomic data supports a noncoelomate ancestry of spiralia.
2014
Based on molecular data three major clades have been recognized within Bilateria: Deuterostomia, Ecdysozoa, and Spiralia. Within Spiralia, small-sized and simply organized animals such as flatworms, gastrotrichs, and gnathostomulids have recently been grouped together as Platyzoa. However, the representation of putative platyzoans was low in the respective molecular phylogenetic studies, in terms of both, taxon number and sequence data. Furthermore, increased substitution rates in platyzoan taxa raised the possibility that monophyletic Platyzoa represents an artifact due to long-branch attraction. In order to overcome such problems, we employed a phylogenomic approach, thereby substantially…
Phylogeny of the parasitic wasp subfamily Charipinae (Hymenoptera, Cynipoidea, Figitidae)
2007
The Charipinae are a major group of hyperparasitoids of Hemiptera. Here, we present the first cladistic analysis of this subfamily's internal relationships, based on 96 morphological characters of adults. The data matrix was analysed using uniformly weighted parsimony. The effects of using alternative weighting schemes were explored by performing additional searches employing implied weights criteria. One of the caveats of implied weights analysis is that it lacks an objective criterion for selecting the value of the concavity function. In the present study, differential weighting was used to explore the sensitivity of our results to the alternative assumptions made in the analysis and to s…
The emergence of lobsters: phylogenetic relationships, morphological evolution and divergence time comparisons of an ancient group (decapoda: achelat…
2014
Lobsters are a ubiquitous and economically important group of decapod crustaceans that include the infraorders Polychelida, Glypheidea, Astacidea and Achelata. They include familiar forms such as the spiny, slipper, clawed lobsters and crayfish and unfamiliar forms such as the deep-sea and "living fossil" species. The high degree of morphological diversity among these infraorders has led to a dynamic classification and conflicting hypotheses of evolutionary relationships. In this study, we estimated phylogenetic relationships among the major groups of all lobster families and 94% of the genera using six genes (mitochondrial and nuclear) and 195 morphological characters across 173 species of…
The phylogeny ofPapaver s. l. (Papaveraceae): Polyphyly or monophyly?
1997
An RFLP analysis of the chloroplast genetrnK of 32 species of the generaPapaver, Roemeria, Stylomecon, andMeconopsis leads to the following conclusions: (1) AsianMeconopsis consists of two distinct clades and is paraphyletic in relation toPapaver, Roemeria, Stylomecon, and the W EuropeanMeconopsis cambrica. (2) Sister group relationships ofRoemeria toPapaver sect.Argemonidium and ofStylomecon toPapaver californicum are well-supported. (3)Meconopsis cambrica is nested withinPapaver (incl.Roemeria andStylomecon). The consideration of morphology, geographical distribution and ecology leads to the conclusion thatM. cambrica is best regarded as a member ofMeconopsis, and thatPapaver arose polyph…
New articulated protospongiid sponges from the early Cambrian Chengjiang biota
2015
Sponges are among the earliest diverging crown-group animals and widely regarded as the earliest biomineralizing animals. Indeed, unambiguous hexactine sponge spicules first occur in the lowermost Cambrian strata of the Fortunian Stage. Articulated sponge skeletons interpreted as hexactinellids and demosponges have been reported from Cambrian Stage 2–3 strata at multiple localities. Articulated sponge skeletons in the Chengjiang biota (Cambrian Stage 3), however, are dominated by forms interpreted as demosponges, despite the exceptional preservation in this biota. Here, we report new articulated sponge skeletons from the Chengjiang biota, including Paradiagoniella magna n. gen. n. sp. and P…
Surrogate-assisted evolutionary biobjective optimization for objectives with non-uniform latencies
2018
We consider multiobjective optimization problems where objective functions have different (or heterogeneous) evaluation times or latencies. This is of great relevance for (computationally) expensive multiobjective optimization as there is no reason to assume that all objective functions should take an equal amount of time to be evaluated (particularly when objectives are evaluated separately). To cope with such problems, we propose a variation of the Kriging-assisted reference vector guided evolutionary algorithm (K-RVEA) called heterogeneous K-RVEA (short HK-RVEA). This algorithm is a merger of two main concepts designed to account for different latencies: A single-objective evolutionary a…
A New Hybrid Mutation Operator for Multiobjective Optimization with Differential Evolution
2011
Differential evolution has become one of the most widely used evolution- ary algorithms in multiobjective optimization. Its linear mutation operator is a sim- ple and powerful mechanism to generate trial vectors. However, the performance of the mutation operator can be improved by including a nonlinear part. In this pa- per, we propose a new hybrid mutation operator consisting of a polynomial based operator with nonlinear curve tracking capabilities and the differential evolution’s original mutation operator, to be efficiently able to handle various interdependencies between decision variables. The resulting hybrid operator is straightforward to implement and can be used within most evoluti…
A Surrogate-assisted Reference Vector Guided Evolutionary Algorithm for Computationally Expensive Many-objective Optimization
2018
We propose a surrogate-assisted reference vector guided evolutionary algorithm for computationally expensive optimization problems with more than three objectives. The proposed algorithm is based on a recently developed evolutionary algorithm for many-objective optimization that relies on a set of adaptive reference vectors for selection. The proposed surrogateassisted evolutionary algorithm uses Kriging to approximate each objective function to reduce the computational cost. In managing the Kriging models, the algorithm focuses on the balance of diversity and convergence by making use of the uncertainty information in the approximated objective values given by the Kriging models, the distr…