Evolution, development and complexity in Pere Alberch (1954–1998)

1999

Crowding effect on adult growth, pre-patent period and egg shedding of Fasciola hepatica

2006

Fascioliasis pathogenesis depends on fluke burden. In human hyperendemic zones, individual infection intensities reach very high levels and the majority of infected subjects should be in the advanced chronic phase. The rat model offers a useful approach for pathological research in the advanced chronic period. The influence of infection intensity per rat on fluke development, pre-patent period and egg shedding (eggs/g faeces/worm) was analysed in 3 groups (I: 1–3 worms/rat; II: 4–6; III: 7–9). Ontogenetic trajectories of fluke body measures followed a logistic model. Results showed that when the burden increases, the maximum values of fluke measures decrease. The crowding effect is manifest…

Comments on "Dental lessons from past to present: Ultrastructure and composition of teeth from plesiosaurs, dinosaurs, extinct and recent sharks" by …

2016

The paper mentioned in the title suggests that several groups of extinct vertebrates used fluoroapatite as a tooth mineral in dentine and enamel when alive; its authors posit that this tooth mineralization drastically changed in all these lineages at some point during their evolution, leading to the use of hydroxyapatite as an alternative primary tooth mineral, because of hitherto unconsidered environmental changes. These conclusions are based on their finding high fluoride levels (i.e. fluoroapatite) in the dentine of fossilised shark teeth as well as in both the dentine and enamel of plesiosaurs, mosasaurs, and dinosaurs, which is in sharp contrast to recent teeth (which contain almost no…

Incorporación de elementos traza en conchas de melanopsis durante el crecimiento : posibilidades de aplicación en paleoecología

1988

El objetivo del presente trabajo está encaminado al estudio de las variaciones de oligoelementos en la concha de un gasterópodo de agua dulce del género Melanopsis (U dufouri (FERUSSAC), con dos morfotipos) y si éstas tienen que ver, o no, con la fluctuación de una serie de parámetros ambientales. La importancia del trabajo radica en la posibilidad de la aplicación paleoecológica de sus resultados, ya que el género MelanopsÍs tiene un abundante registro fósil durante todo el Cenozoico. La incorporación de oligoelementos se efectúa a medida que la concha va creciendo por acreción; lo ideal sería que tal crecimiento fuera circadiano, ya que se podría seguir día a día, sobre la concha, la fluc…