Species are commonly delimited on the basis of gaps in patterns of morphological variation, but there seems to be little recent work on methods to objectively assess such gaps. Here, we introduce a statistical approach that uses measurements of continuous morphological characters and geographic variation in those characters to (i) measure the strength of the evidence for the existence of a gap ...

The threespine stickleback (Gasterosteus aculeatus) is rapidly emerging as a new model genetic system to study questions at the interface of evolution and development. The relatively rapid and recent diversification of this small teleost fish, combined with the development of genetic and genomic tools for this fish, provides an unprecedented opportunity to identify the genetic and molecular bas...

1 This paper was presented at the session “Exploring the Nature of Human Biological Diversity: Myth v. Reality” at the American Anthropological Association (AAA) 2003 Annual Meeting on November 21, 2003 in Chicago, Illinois. The session was sponsored by the AAA Understanding Race and Human Variation project, organized by AAA’s Society for Medical Anthropology and Committee on Minority Affairs, ...

Method and result: The aim of this study was to describe the common Carotid Artery Bifurcation (CB). Measurements were performed on 100 cadavers by the direct inspection method. The vertebra level of CB was differently distributed in distance of the whole neck measured along the vertebral column between upper borders of C1-C2 to lower border of C5. 54% of the level of CB was asymmetrical betwee...

Morphometrics of 23 United States populations of Xiphinema americanum sensu lato, sharing the characteristics of an offset lip region and conoid tail, were examined and analyzed statistically by canonical discriminant analysis (CDA). Specimens were collected from Arkansas, Georgia, Tennessee, Mississippi, Florida, Oklahoma, California, and North Dakota. Eleven measurements and body ratios obtai...

the barn owl, tyto alba (scopoli, 1769), occurs worldwide and shows a considerable amount of morphological and geographical variation, leading to the recognition of many subspecies around the world. yet comprehensive study on this species needs to be done. data from mitochondrial gene (cytb) with 620bp length is analyzed for 30 individuals around the world. maximum likelihood (ml), maximum pars...

The morphological specifications play a substantial role in classification and breeding programs of various plant taxa. In the current study, some macro- and micro-morphological features of Salvia nemorosa, Salvia syriaca, Salvia frigida and Salvia virgata (three accessions), were investigated using scanning electron microscopy and image analysis program. The completely randomized design (CRD) ...

Having knowledge about genetic relationships among accessions is necessary for developing breeding strategies to produce improved cultivars. In present study, genetic diversity and inter-relationship among 29 genotypes of citrus were comparatively analyzed using morphological and RAPD markers. Significant variability was observed among citrus genotypes for 61 quantitative and qualitative morpho...