Search publications of the members of the Royal Belgian institute of natural Sciences
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Incised Pleistocene valleys in the Western Belgium coatsal plain: Age, origins and implications for the evolution of the Southern North Sea basin
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Drapetis bruscellensis (Diptera: Hybotidae) a new species for science from the outskirts of Brussels, a not so cryptic species supported by COI barcoding
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Late Stone Age human remains from Ishango (Democratic Republic of Congo): New insights on Late Pleistocene modern human diversity in Africa
- Although questions of modern human origins and dispersal are subject to intense research within and outside Africa, the processes of modern human diversification during the Late Pleistocene are most often discussed within the context of recent human genetic data. This situation is due largely to the dearth of human fossil remains dating to the final Pleistocene in Africa and their almost total absence from West and Central Africa, thus limiting our perception of modern human diversification within Africa before the Holocene. Here, we present a morphometric comparative analysis of the earliest Late Pleistocene modern human remains from the Central African site of Ishango in the Democratic Republic of Congo. The early Late Stone Age layer (eLSA) of this site, dated to the Last Glacial Maximum (25–20 Ky), contains more than one hundred fragmentary human remains. The exceptional associated archaeological context suggests these remains derived from a community of hunter-fisher-gatherers exhibiting complex social and cognitive behaviors including substantial reliance on aquatic resources, development of fishing technology, possible mathematical notations and repetitive use of space, likely on a seasonal basis. Comparisons with large samples of Late Pleistocene and early Holocene modern human fossils from Africa and Eurasia show that the Ishango human remains exhibit distinctive characteristics and a higher phenotypic diversity in contrast to recent African populations. In many aspects, as is true for the inner ear conformation, these eLSA human remains have more affinities with Middle to early Late Pleistocene fossils worldwide than with extant local African populations. In addition, cross-sectional geometric properties of the long bones are consistent with archaeological evidence suggesting reduced terrestrial mobility resulting from greater investment in and use of aquatic resources. Our results on the Ishango human remains provide insights into past African modern human diversity and adaptation that are consistent with genetic theories about the deep sub-structure of Late Pleistocene African populations and their complex evolutionary history of isolation and diversification.
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Species limits, interspecific hybridization and phylogeny in the cryptic land snail complex Pyramidula: The power of RADseq data
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A revision of the Thyropygus allevatus group. Part V: Nine new species of the extended opinatus subgroup, based on morphological and DNA sequence data (Diplopoda: Spirostreptida: Harpagophoridae)
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DNA analyses reveal abundant homoplasy in taxonomically important morphological characters of Eusiroidea (Crustacea, Amphipoda)
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Description of a new species of Chicoreus {Triplex) (Gastropoda: Muricidae) from the northern Red Sea, Egypt
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Lanceolaria bogani (Bivalvia: Unionidae), a new species from Vietnam
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Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species
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Impacts of Climate Change on the Global Invasion Potential of the African Clawed Frog Xenopus laevis
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Looking beneath the tip of the iceberg: diversification of the genus Epimeria on the Antarctic shelf (Crustacea, Amphipoda)
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Patterns of neutral and adaptive genetic diversity across the natural range of Sugar pine (Pinus lambertiana).
- Demographic and environmental forces shape geographical patterns of genetic diversity. Knowledge thereof is not only important for evolutionary ecologists but, in light of future climate change, will be of interest to conservation biologists as well. Sugar pine (Pinus lambertiana Dougl.) is an ecologically important species found in mixed conifer forests across western North America. We applied a candidate-genebased environmental study to infer spatial patterns in neutral genetic variation and to identify genetic variants associated with local adaptation to drought. Using a panel of 186 candidate gene single nucleotide polymorphisms (SNP), we genotyped 313 individual trees sampled across the entire state of California, USA. We found evidence for a large-scale subdivision into two genetic clusters along the latitudinal axis and increased genetic similarity among sugar pines within a 200– 300-km boundary. Associating allelic to environmental variation indicated nine putative SNPs related to local adaptation to drought. These results provide insights into neutral population structure across the natural range of sugar pine and further substantiated a key role of the mitochondrial import inner membrane machinery in enhanced tolerance to drought and constitute important steps into unravelling the eco-evolutionary dynamics in sugar pine.
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Field Method for testing Repellency of an Icaridin-Containing Skin Lotion against Vespid Wasps
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On a collection of Odonata from Cambodia, with the first record of Sinictionogomphus clavatus and a description of the female of Zyxomma breviventre
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Inter- and intraspecific variation in the surface pattern of the dermal bones of two sturgeon species
- Archaeological bone remains of sturgeon (Acipenser sturio/Acipenser oxyrinchus) from northwestern Europe are often identified to species on the basis of their surface morphology and then used to reconstruct the spatial distribution of the two species through time. The dermal bones of A. sturio are said to have an exterior surface pattern consisting of tubercles, while those of A. oxyrinchus are said to display alveoli. In the present paper, the validity of the surface pattern as a species-specific characteristic is critically assessed. To this purpose, dermal plates from modern, genetically identified museum specimens were studied and the surface morphology observed in a series of archaeological remains was compared with the genetic identifications obtained on these same remains. The analyses show that the surface pattern of dermal bones is related to the size of the individual, with the pattern of small A. oxyrinchus being similar to that of A. sturio. In addition, variations in the surface pattern among the bones of a single individual and within the same bone have been observed. These findings explain previous conflicting results between morphological and genetic identifications and allow the formulation of some recommendations for more accurate morphological identification of isolated archaeological sturgeon dermal bones.
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Mitogenomics reveals high synteny and long evolutionary histories of sympatric cryptic nematode species
- Species with seemingly identical morphology but with distinct genetic differences are abundant in the marine environment and frequently co-occur in the same habitat. Such cryptic species are typically delineated using a limited number of mitochondrial and/or nuclear marker genes, which do not yield information on gene order and gene content of the genomes under consideration. We used next-generation sequencing to study the composition of the mitochondrial genomes of four sympatrically distributed cryptic species of the Litoditis marina species complex (PmI, PmII, PmIII, and PmIV). The ecology, biology, and natural occurrence of these four species are well known, but the evolutionary processes behind this cryptic speciation remain largely unknown. The gene order of the mitochondrial genomes of the four species was conserved, but differences in genome length, gene length, and codon usage were observed. The atp8 gene was lacking in all four species. Phylogenetic analyses confirm that PmI and PmIV are sister species and that PmIII diverged earliest. The most recent common ancestor of the four cryptic species was estimated to have diverged 16 MYA. Synonymous mutations outnumbered nonsynonymous changes in all protein-encoding genes, with the Complex IV genes (coxI-III) experiencing the strongest purifying selection. Our mitogenomic results show that morphologically similar species can have long evolutionary histories and that PmIII has several differences in genetic makeup compared to the three other species, which may explain why it is better adapted to higher temperatures than the other species.
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Spatiotemporal variation and sediment retention effects on nematode communities associated with Halimeda opuntia (Linnaeus) Lamouroux (1816) and Sargassum polyceratium Montagne (1837) seaweeds in a tropical phytal ecosystem
- Nematodes play an important role in ecological processes and are one of the most abundant meiofaunal organisms associated with seaweeds. Yet, knowledge on seaweed bed ecosystems is limited. Nematodes associated with Sargassum polyceratium and Halimeda opuntia were compared in two transects, 80 m apart and parallel to the beach line in Cupe Beach, Brazil. The temporal variation during the dry and rainy seasons and the effect of sediment retention by the seaweed on nematode density and composition were investigated. The differences in nematode communities between the two seasons were mainly caused by the increase in density of the most abundant genera in the rainy season. A significant difference was observed between the nematode communities of the two transects for H. opuntia. The nematode communities of both seaweed species did not differ significantly in the same transect. The genus Euchromadora was dominant in both seaweed species. The amount of sediment retained by the seaweeds did not affect the overall nematode density. However, it was positively correlated with the density of Draconema and Euchromadora in both seaweeds, and both genera were exclusively found associated with seaweeds. This result opposes the idea that the more sediment retained by the seaweed, the higher the nematode overall density and the higher the number of nematodes originally coming from the sediment.
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Coexisting cryptic species of the Litoditis marina complex (Nematoda) show differential resource use and have distinct microbiomes with high intraspecific variability
- Differences in resource use or in tolerances to abiotic conditions are often invoked as potential mechanisms underlying the sympatric distribution of cryptic species. Additionally, the microbiome can provide physiological adaptations of the host to environmental conditions. We determined the intra- and interspecific variability of the microbiomes of three cryptic nematode species of the Litoditis marina species complex that co-occur, but show differences in abiotic tolerances. Roche 454 pyrosequencing of the microbial 16S rRNA gene revealed distinct bacterial communities characterized by a substantial diversity (85-513 OTUs) and many rare OTUs. The core microbiome of each species contained only very few OTUs (2-6), and four OTUs were identified as potentially generating tolerance to abiotic conditions. A controlled experiment in which nematodes from two cryptic species (Pm1 and Pm3) were fed with either an E. coli suspension or a bacterial mix was performed, and the 16S rRNA gene was sequenced using the MiSeq technology. OTU richness was 10-fold higher compared to the 454 data set and ranged between 1118 and 7864. This experiment confirmed the existence of species-specific microbiomes, a core microbiome with few OTUs, and high interindividual variability. The offered food source affected the bacterial community and illustrated different feeding behaviour between the cryptic species, with Pm3 exhibiting a higher degree of selective feeding than Pm1. Morphologically similar species belonging to the same feeding guild (bacterivores) can thus have substantial differences in their associated microbiomes and feeding strategy, which in turn may have important ramifications for biodiversity-ecosystem functioning relationships.
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Let the dead speak…comments on Dibble et al.'s reply to “Evidence supporting an intentional burial at La Chapelle-aux-Saints”
- In a reply to our paper presenting new evidence supporting an intentional Neanderthal burial at La Chapelle-aux-Saints (Corrèze, France), Dibble et al. (2014) reviewed our data in relation to the original Bouyssonie publications. They conclude that alternative hypotheses can account for the preservation of the human remains within a pit. Here we present new data from our recent excavations and highlight several misinterpretations of the Bouyssonie publications, which, when taken together refute most of their arguments. Moreover, we show that the different hypotheses proposed by Dibble et al. cannot work together and fail to provide a credible explanation for the deposit, reinforcing our demonstration that the burial hypothesis remains the most parsimonious explanation for the preservation of the Neanderthal skeletal material at La Chapelle-aux-Saints.
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Change in Historical Range of the Ural Owl in Europe
- A carpometacarpus recovered during archaeological excavations in the town of Quaregnon is the westernmost find ever reported in Europe of a Ural Owl (Strix uralensis), and the first occurrence for Belgium. Both the morphology of the skeletal element and its measurements rule out an identification as any of the other Strigiformes from the Western Palearctic. The provenance of this specimen, that dates to the medieval period (10th-12th centuries AD), is discussed. It is hypothesized that the bird was a wild animal, but the available evidence does not unequivocally determine whether it belonged to a local, breeding population that went extinct or if it came from a more distant population. However, a survey of other zooarchaeological finds of Ural Owl in Europe shows that the species occurred farther west in the past, outside the present natural breeding range. This suggests that Ural Owl may have found suitable nesting biotopes in Belgium and northern France during the medieval period.
