Bibliografia reciente sobre morfometría

Morphological evolution in Tropidurinae squamates: an integrated view along a continuum of ecological settings

2009-11-06T12:14:00Z

Variation in squamate foot morphology is likely relevant during evolutionary processes of habitat colonization because distinct surfaces differ in energetic and functional demands for locomotion. We combined new foot morphological data with published information of limb and tail lengths to investigate evolutionary changes possibly associated with the differential usage of ecological settings by Tropidurinae species. Several traits exhibited significant phylogenetic signal, and we performed conventional and phylogenetic regressions of PC scores...

Contrasting patterns of phenotypic variation linked to chromosomal inversions in native and colonizing populations of Drosophila subobscura

2009-11-03T10:41:00Z

In fewer than two decades after invading the Americas, the fly Drosophila subobscura evolved latitudinal clines for chromosomal inversion frequencies and wing size that are parallel to the long-standing ones in native Palearctic populations. By sharp contrast, wing shape clines also evolved in the New World, but the relationship with latitude was opposite to that in the Old World. Previous work has suggested that wing trait differences among individuals are partially due to the association between chromosomal inversions and particular alleles...

Angry Faces: Facial Structure Linked To Aggressive Tendencies, Study Suggests

2009-11-02T07:00:00Z

Angry words and gestures are not the only way to get a sense of how temperamental a person is. According to new findings, a quick glance at someone's facial structure may be enough for us to predict their tendency towards aggression.

Phylogeography and counter-intuitive inferences in island biogeography: evidence from morphometric markers in the mobile butterfly Maniola jurtina (Linnaeus) (Lepidoptera, Nymphalidae)

2009-10-30T18:31:41Z

Ecological and evolutionary factors in the morphological diversification of South American spiny rats

2009-10-30T18:31:27Z

Differing evolutionary patterns underlie convergence on elongate morphology in endemic fishes of Lake Waccamaw, North Carolina

2009-10-30T18:31:15Z

Changes in ventral head width, a discriminating shape factor among African cichlids, can be induced by chronic hypoxia

2009-10-30T18:30:55Z

Testing subspecies hypothesis with molecular markers and morphometrics in the Pacific white tern complex

2009-10-30T18:30:40Z

Correction of a bootstrap approach to testing for evolution along lines of least resistance

2009-10-30T06:16:00Z

Testing for an association between the leading vectors of multivariate trait (co)variation within populations (the 'line of least resistance') and among populations is an important tool for exploring variational bias in evolution. In a recent study of stickleback fish populations, a bootstrap-based test was introduced that takes into account estimation error in both vectors and hence improves the previously available bootstrap method. Because this test was implemented incorrectly, however, I here describe the correct test protocol and provide...

The endangered cyprinodont Aphanius ginaonis (Holly, 1929) from southern Iran is a valid species: evidence from otolith morphology

2009-10-27T18:24:43Z

Abstract Aphanius Nardo, 1827 (Actinopterygii, Cyprinodontidae) is a widely distributed genus in the Mediterranean and Persian Gulf area and includes several endangered species. The otolith morphology in Aphanius is known to represent a valuable tool for the taxonomy, and is also indicative for the genetic diversity of a particular population. The present study focuses on the otoliths of the endangered A. ginaonis (Holly, 1929), which is endemic to the Geno hot spring in southern Iran. The taxonomic status of A. ginaonis has repeatedly...

Phenotypic Plasticity of Leaf Shape along a Temperature Gradient in <italic>Acer rubrum</italic>

2009-10-29T07:00:00Z

Both phenotypic plasticity and genetic determination can be important for understanding how plants respond to environmental change. However, little is known about the plastic response of leaf teeth and leaf dissection to temperature. This gap is critical because these leaf traits are commonly used to reconstruct paleoclimate from fossils, and such studies tacitly assume that traits measured from fossils reflect the environment at the time of their deposition, even during periods of rapid climate change. We measured leaf size and shape in Acer...

Vertebrae in compression: Mechanical behavior of arches and centra in the gray smooth-hound shark (Mustelus californicus)

2009-10-27T14:41:00Z

In swimming sharks, vertebrae are subjected, in part, to compressive loads as axial muscles contract. We currently have no information about which vertebral elements, centra, arch cartilages, or both, actually bear compressive loads in cartilaginous vertebrae. To address this issue, the goal of this experiment was to determine the load-bearing ability of arch and centrum cartilages in compression, to determine the material properties of shark vertebrae, and to document fracture patterns in the centra with and without the arches. Intact...

Ontogenetic change in skull morphology and mechanical advantage in the spotted hyena (Crocuta crocuta)

2009-10-27T14:41:00Z

Weaning represents a challenging transition for young mammals, one particularly difficult for species coping with extreme conditions during feeding. Spotted hyenas (Crocuta crocuta) experience such extreme conditions imposed by intense feeding competition during which the ability to consume large quantities of food quickly is highly advantageous. As adult spotted hyenas have massive skulls specialized for durophagy and can feed very rapidly, young individuals are likely at a competitive disadvantage until that specialized morphology is...

Extreme Cranial Ontogeny in the Upper Cretaceous Dinosaur <italic>Pachycephalosaurus</italic>

2009-10-27T07:00:00Z

Background Extended neoteny and late stage allometric growth increase morphological disparity between growth stages in at least some dinosaurs. Coupled with relatively low dinosaur density in the Upper Cretaceous of North America, ontogenetic transformational representatives are often difficult to distinguish. For example, many hadrosaurids previously reported to represent relatively small lambeosaurine species were demonstrated to be juveniles of the larger taxa. Marginocephalians (pachycephalosaurids + ceratopsids) undergo comparable and...

Dynamics of sexual and parthenogenetic populations of Eucypris virens (Crustacea: Ostracoda) in three temporary ponds

2009-10-20T15:23:06Z

Abstract Eucypris virens is a freshwater ostracod in which both sexual reproduction and parthenogenesis occur. Sympatric coexistence of both reproductive modes is known in zones of overlap. This renders the species a potentially valuable model organism to study the ‘queen of evolutionary problems’, i.e. why sex is so successful despite its costs (paradox of sex). In order to maximally exploit this potential, a broad knowledge of the species’ ecology is essential, including an understanding of its life history and population dynamics....

A TEST FOR COPE'S RULE

2009-09-09T23:42:00Z

Cope's Rule refers to the tendency of body size to increase along an evolutionary lineage. This rule is commonly tested by comparing size differences in pairs of taxa, one of which is assumed to be ancestral to the other. It has recently been pointed out that this approach fails to account for the unknown number of speciation events separating each pair. Here, a test that does account for this degree of separation is described and applied to some published data for dinosaurs. A by-product of the analysis is an estimate of the origination rate...

Congruent Climate‐Related Genecological Responses from Molecular Markers and Quantitative Traits for Western White Pine (Pinus monticola)

2009-10-16T15:38:54Z

International Journal of Plant Sciences, Volume 170, Issue 9, Page 1120-1131, November/December 2009. Analyses of molecular and quantitative genetic data demonstrate the existence of congruent climate‐related patterns in western white pine (Pinus monticola). Two independent studies allowed comparisons of amplified fragment length polymorphism (AFLP) markers with quantitative variation in adaptive traits. Principal component analyses were conducted on seedling traits in common gardens collected from 58 sites; principal coordinate...

[Report] Tyrannosaurid Skeletal Design First Evolved at Small Body Size

2009-10-16T19:04:18Z

The distinct features of Tyrannosaurs, such as their large skull and tiny arms, appear in an earlier small-bodied species. Authors: Paul C. Sereno, Lin Tan, Stephen L. Brusatte, Henry J. Kriegstein, Xijin Zhao, Karen Cloward

Adapting generalized frequency coding to use colour spectra in the determination of phylogenetic relationships: an example with hummingbirds

2009-10-12T15:12:34Z

An evaluation of the systematic value of skull morphology in the Trimeresurus radiation (Serpentes: Viperidae: Crotalinae) of Asian pitvipers

2009-10-12T15:12:12Z