– The desert tortoise (Gopherus agassizii) has traditionally been viewed as an archetypal desert-adapted vertebrate. However, evidence from historical ecology, phylogenetics, anatomy, physiology, and biogeography qualifies this view significantly. Ancestors of G. agassizii stabilized as an essentially modern morph some 17-19 million yrs ago ago, perhaps 12 million yrs before the formation of ma...

Heterothermy plays an important role in lowering the costs of thermoregulation in endotherms by reducing water and energy requirements. We tested predictions that birds in arid habitats should express fine-scale variation in their thermoregulatory patterns as a function of prevailing climatic conditions. We assessed effects of air temperature (Tair) and water vapor pressure deficit (D) on body ...

We have recently discovered a variety of unrelated phototrophic microorganisms (two microalgae and one cyanobacteria) in specialized terrestrial habitats at The Coastal Range of the Atacama Desert. Interestingly, morphological and molecular evidence suggest that these three species are all recent colonists that came from aquatic habitats. The first case is Cyanidiales inhabiting coastal caves. ...

Recently, in several areas of the Middle East, a sharp increase of cutaneous leishmaniasis was observed in suburbs of larger towns including Jerusalem. In some of these areas, poor housing conditions and unsuitable waste management was suspected to provide ideal conditions for sand fly breeding, but hard data on diurnal resting sites and breeding habitats of most sand fly species are scant. In ...

Maintaining the integrity of the cuticular transpiration barrier even at elevated temperatures is of vital importance especially for hot-desert plants. Currently, the temperature dependence of the leaf cuticular water permeability and its relationship with the chemistry of the cuticles are not known for a single desert plant. This study investigates whether (i) the cuticular permeability of a d...

Current theories regarding colonization of South America by mammals are divided between those supported by fossil evidence, which suggest the original mammal fauna of the isolated continent was augmented by early immigrants (primates, caviomorph rodents, and later, procyonids) with a final large influx of northern mammals occurring with the formation of the Panama land bridge, and an opposing v...

Rainfall events can be characterized as "pulses", which are discrete and variable episodes that can significantly influence the structure and function of desert ecosystems, including shifts in aboveground net primary productivity (ANPP). To determine the threshold and hierarchical response of rainfall event size on the Normalized Difference Vegetation Index (NDVI, a proxy for ANPP) and the diff...