Search results for "morphometrics"
showing 10 items of 108 documents
Differentiation in morphology and habitat partitioning of genetically characterized Gammarus fossarum forms (Amphipoda) across a contact zone
2000
Evolutionary processes do not affect all character types equally. Depending on environmental effects, morphological and ecological evolution may be uncoupled from molecular evolution. A natural contact zone between two forms of the amphipod Gammarus fossarum was used to assess the levels of differentiation in genetic, morphological and habitat characters. About 50 individuals per population were analysed for six enzyme loci in 72 populations and four size-standardized morphometric traits in a subset of 32 populations. Nine environmental parameters per population were used to characterize the habitat. All three character sets revealed significant divergences between G. fossarum forms. The ea…
L'ornementation des bracelets de l'âge du Bronze européen : analyse descriptive et perspectives
2013
This paper discusses the ornamental patterns of metal bracelets worn on the arms and legs of people during the European Bronze Age. A method has been specially created to study geometric patterns. Some sets of metal bands (bracelets métalliques) of Bronze Age reach a high level of complexity due to the use of combined patterns in an overall structure. This paper deals with an experimental criterion concerning this phenomenon. The methodology, developed for the purpose i.e. the experimental criterion developed for the purpose of this study, was to extract geometric patterns from the original media. The principle is to release the geometrical compositions of the deformations induced by the mo…
The Human Biodiversity in the Middle of the Mediterranean. Study of native and settlers populations on the Sicilian context
2020
[IT] Negli ultimi 200.000 anni, la specie umana si è diffusa in tutta la Terra, adattando la sua morfologia e fisiologia a un'ampia gamma di habitat. Lo scheletro umano ha quindi registrato i principali effetti ambientali e di conseguenza i reperti scheletrici assumono grande importanza nell'indagine dei processi evolutivi. Oggi le moderne tecniche di indagini quantitative delle principali caratteristiche morfologiche consentono di metterle in relazione con la variabilità genetica. La posizione geografica della Sicilia, l'isolamento e la sua lunga e dinamica storia di colonizzazione (diversi e numerosi contributi culturali e biologici) hanno creato un contesto peculiare che consente uno stu…
Morphological variability in and distributional data on phaleria bimaculata populations from islands of the central mediterranean area
2011
This study aimed to collect new taxonomic and distribution data on Phaleria bimaculata (L.) (Coleoptera Tenebrionidae) from Sicily (southern Italy), the circum-Sicilian islands and the Maltese archipelago. Particular attention was paid to the diagnostic morphological features observed in the populations sampled, focusing on the subspecies Phaleria bimaculata marcuzzii Aliquò. P. bimaculata individuals were collected from 20 different locations, of which 2 were located in the Sicilian mainland, 9 in circum-Sicilian islands and 9 in the Maltese Islands. In addition, four Phaleria acuminata Kuster populations were also recorded along southern Sicilian shores. The two Phaleria species were neve…
Differences in inner ear asymmetry levels between slow-moving and fast-moving primates
2021
International audience; The vestibular system of the inner ear, highly involved in maintaining balance during activities and positional behaviour of animals, has been deeply studied in order to link its morphology with the specific type of locomotion. Previous studies (e.g. Perier et al. 2016, Gonzales et al. 2018) have shown that, in primates, the amount of morphological variation is higher in slow-moving species than in fast-moving ones. These results indicate a lower selective pressure and a reduced functional demand for postural adjustments in the former group, and a higher selective pressure for balance and postural capabilities in the latter. In this study, we assessed if the differen…
Differentiation of
2019
Trichuris trichiura is a nematode considered as the whipworm present in humans and primates. The systematics of the genus Trichuris is complex. Morphological studies of Trichuris isolated from primates and humans conclude that the species infecting these hosts is the same. Furthermore, numerous molecular studies have been carried out so far to discriminate parasite species from humans and Non-Human Primates using molecular techniques, but these studies were not performed in combination with a parallel morphological study. The hypothesised existence of more species of Trichuris in primates opens the possibility to revise the zoonotic potential and host specificity of T. trichiura and other p…
Morphometric diversity of the mussel Brachidontes pharaonis in different coastal environments
2010
In the debate on how and why biodiversity evolves spatially and temporally and in an attempt to assess the further effects of anthropogenic activities, the ability of marine invertebrate to express a large spectrum of phenotypical plasticity can have a central role. The ability of a single genotype to produce more than one alternative form of morphology and/or physiological state should be larger in species living in highly changing waters like shallow habitats. Invertebrates, there, usually experience ample changes of temperature and food availability on annual, seasonal, diurnal and hourly bases which are the two main drivers leading the life histories of these organisms. In such circumst…
3D Geometric morphometrics to investigate Cercopithecini evolution
2014
3D Geometric Morphometrics has been used on a preliminary dataset of 163 crania and 148 mandibles of primates. We sampled 27 species from Cercopithecidae and Hominidae, collected in 7 different museums. Our sampling campaign was carried on with the use of a 3D-digitizer Microscribe G2X and the data were processed through the software Morphologika. The preliminary PCA analyses on crania highlight the presence of two different groups, which distinguish some Chlorocebus and Unknown Cercopithecus samples from all the others. Regarding on mandibular shape analyses, we found a light cluster of Cercopithecus samples. The “Sex” variable does not affect the reliability of the analysis, probably beca…
Wing morphometrics as a possible tool for the diagnosis of the Ceratitis fasciventris, C. anonae, C. rosa complex (Diptera, Tephritidae)
2015
Abstract Previous attempts to resolve the Ceratitis FAR complex (Ceratitis fasciventris, Ceratitis anonae, Ceratitis rosa, Diptera, Tephritidae) showed contrasting results and revealed the occurrence of five microsatellite genotypic clusters (A, F1, F2, R1, R2). In this paper we explore the potential of wing morphometrics for the diagnosis of FAR morphospecies and genotypic clusters. We considered a set of 227 specimens previously morphologically identified and genotyped at 16 microsatellite loci. Seventeen wing landmarks and 6 wing band areas were used for morphometric analyses. Permutational multivariate analysis of variance detected significant differences both across morphospecies and g…
Morphologically similar but not closely related: the long-spored species of Subulicystidium (Trechisporales, Basidiomycota)
2020
AbstractSpecies boundaries and geographic distribution of corticioid fungi (resupinate Basidiomycota) are often poorly known. Our recent study on Subulicystidium showed that species diversity in this genus is at least twice as high as previously recognized. This re-estimation of the species diversity was based on a study of only a part of the genus. The present study sheds light on molecular and morphological diversity of three more species. We generated 27 ITS and 24 28S nuclear ribosomal DNA sequences from 49 specimens labelled as Subulicystidium cochleum, S. longisporum and S. perlongisporum and collected in distant geographic localities. We assessed pairwise dissimilarities and phylogen…