Search results for "morphometric"
showing 10 items of 149 documents
Microevolution in the sicilian shrew crocidura sicula (mammalia, soricidae) tested by rapd-pcr fingerprinting
1997
Genetic variation in samples of the endemic Crocidura sicula living in Sicily and in two surrounding small islands, Marettimo and Ustica, was analysed by Random Amplified Polymorphic DNA fingerprinting (RAPD) and compared to morphometrics and external phenotypes. Molecular variation in the random sample of 99 DNA fragments of the Ustica shrews, showing.a melanic fur and a size-shape variation in skull morphometrics, is of comparable size to that of the of northwestern and northeastern samples Sicily (Tufanio and Madonie). In the Marettimo shrews, bicoloured (grey and white) animals like those coming from Sicily and presenting a significant reduction in body-size and skull morphometrics, mol…
The role of post-natal ontogeny in the evolution of phenotypic diversity in Podarcis lizards
2011
Understanding the role of the developmental pathways in shaping phenotypic diversity allows appreciating in full the processes influencing and constraining morphological change. Podarcis lizards demonstrate extraordinary morphological variability that likely originated in short evolutionary time. Using geometric morphometrics and a broad suite of statistical tests, we explored the role of developmental mechanisms such as growth rate change, ontogenetic divergence ⁄ convergence ⁄ parallelism as well as morphological expression of heterochronic processes in mediating the formation of their phenotypic diversity during the post-natal ontogeny. We identified hypermorphosis – the prolongation of …
Differentiation of Trichuris species using a morphometric approach
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…
The Sicilian (Crocidura sicula) and the Canary (C. canariensis) shrew (Mammalia, Soricidae): Peripheral isolate formation and geographic variation
1995
Abstract The skull and mandible morphometrics of two insular and endemic taxa (C. sicula and C. canariensis) from the Sicilian and Canary archipelagos, both having exactly the same karyotype were analysed by principal component and canonical variate analyses and related multivariate techniques. Information available in the literature was also employed to obtain a better approach to the systematics relationships in this taxon. Specimens of C. suaveolens, C. leucodon, C. whitakeri and C. russula from the Mediterranean, and C. esuae from the Pleistocene of Spinagallo (Sicily) were used as references. The results of multivariate analyses of the metric and non‐metric characters of the skull and …
Phenotypes of intermediate forms of Fasciola hepatica and F. gigantica in buffaloes from Central Punjab, Pakistan.
2013
AbstractFascioliasis is an important food-borne parasitic disease caused by the two trematode species, Fasciola hepatica and Fasciola gigantica. The phenotypic features of fasciolid adults and eggs infecting buffaloes inhabiting the Central Punjab area, Pakistan, have been studied to characterize fasciolid populations involved. Morphometric analyses were made with a computer image analysis system (CIAS) applied on the basis of standardized measurements. Since it is the first study of this kind undertaken in Pakistan, the results are compared to pure fasciolid populations: (a) F. hepatica from the European Mediterranean area; and (b) F. gigantica from Burkina Faso; i.e. geographical areas wh…
Degree of terrestrial activity of the elusive sun-tailed monkey (Cercopithecus solatus) in Gabon: Comparative study of behavior and postcranial morph…
2015
We carried out a multidisciplinary study linking behavioral and morphological data from a little-known guenon species, Cercopithecus solatus, endemic to Gabon. Over a period of 9 months, we documented the pattern of stratum use associated with postural and locomotor behavior by direct observation (650 hrs) of a semi-free-ranging breeding colony. We also conducted a morphometric analysis of the humerus and limb proportions of 90 adult specimens from 16 guenon species, including C. solatus. Field observations indicated that C. solatus monkeys spent a third of their time on the ground, similar to semi-terrestrial guenon species. We detected two patterns of stratum use: at ground level, and in …
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…