Comparative developmental biologists have proposed models to describe patterns of conserved features in vertebrate ontogeny. The hourglass model suggests evolutionary change is most difficult at an intermediate "phylotypic" stage, the adaptive penetrance model suggests change is easiest at an intermediate stage, and the early conservation model suggests change is easier later in ontogeny. Altho...

Signal ontogeny was examined in green anoles (Anolis carolinensis). From 1,246 head bob displays given by 114 juveniles, it was found that juveniles possessed all 3 display types (A, B, and C) described for adults and that C displays were present at hatching, but A and B displays appeared to emerge gradually from a common precursor. Durations of the head bobs and pauses that make up juvenile di...

IL-17 producers in T cell subsets have been recently identified to play protective roles against bacterial infection by inducing neutrophil infiltrations, organizing granulomas and acquired immunity. During ontogeny, T cells develop, maturate and localize at different tissues depending on V repertoires. V 1+, V 4+ and V 6+ cells are reportedly able to produce IL-17. V 6+ cells, which develop in...

As there is limited knowledge regarding the longitudinal development and early ontogeny of naïve and regulatory CD4(+) T-cell subsets during the first postnatal year, we sought to evaluate the changes in proportion of naïve (thymic and central) and regulatory (resting and activated) CD4(+) T-cell populations during the first postnatal year. Blood samples were collected and analyzed at birth, 6 ...

The erythroid colon-forming technique has been used to study the erythropoietin (Ep) sensitivity of CFU-E during ontogenesis. Evidence is provided which indicates that an age-related decreasing Ep sensitivity of CFU-E occurs as the animal develops. In addition, an intermediate Ep-sensitive CFU-E population represented by the 2-day-old neonate is present during the transition from foetus to adul...

A new specimen attributable to an immature individual of Pachyrhinosaurus perotorum (Dinosauria, Ceratopsidae) from the Kikak-Tegoseak Quarry in northern Alaska preserves a mix of features that provides refinement to the sequence of ontogenetic stages and transformations inferred for the development of the nasal boss in Pachyrhinosaurus. The new specimen consists of an incomplete nasal that inc...

Right This is the peer reviewed version of the following article: Masuda, R. (2011), Ontogeny of swimming speed, schooling behaviour and jellyfish avoidance by Japanese anchovy Engraulis japonicus. Journal of Fish Biology, 78: 1323‒1335, which has been published in final form at http://dx.doi.org/10.1111/j.1095-8649.2011.02936.x; This is not the published version. Please cite only the published...

The concept of ontogenetic niche is used here to interpret how species-typical behaviors develop through active, context-dependent processes. Ontogenetic niches typically include social stimuli, such as those arising from parents, siblings, and others that provide ‘nurturing’ in the form of resources, stimulation, and affordances for development. This approach is a useful alternative to wrestli...

This study examines interpopulation variations in the facial skeleton of 10 modern human populations and places these in an ontogenetic perspective. It aims to establish the extent to which the distinctive features of adult representatives of these populations are present in the early post natal period and to what extent population differences in ontogenetic scaling and allometric trajectories ...