Life originated in anoxia, but many organisms came to depend upon oxygen for survival,
independently evolving diverse respiratory systems for acquiring oxygen from the …

Insects are small relative to vertebrates, possibly owing to limitations or costs associated
with their blind-ended tracheal respiratory system. The giant insects of the late Palaeozoic …

Physiological Systems in Insects discusses the roles of molecular biology,
neuroendocrinology, biochemistry, and genetics in our understanding of insects. All …

Insects are the most ecologically important multicellular heterotrophs in terrestrial systems.
They play critical roles in ecological food webs, remain devastating agricultural and medical …

This review discusses body size and mass as they relate to the Orthoptera (crickets,
katydids, grasshoppers) and the Phasmatodea (walkingsticks). It addresses the expression …

Body size profoundly affects many aspects of animal biology, including metamorphosis,
allometry, size-dependent alternative pathways of gene expression, and the social and …

Insects can experience functional hypoxia, a situation in which O2 supply is inadequate to
meet oxygen demand. Assessing when functional hypoxia occurs is complex, because …

Recent studies have suggested that Paleozoic hyperoxia enabled animal gigantism, and the
subsequent hypoxia drove a reduction in animal size. This evolutionary hypothesis depends …

The developmental regulation of body size is a fundamental life-history characteristic that in
most animals is tied to the transition from juvenile to adult form. In holometabolous insects …

ABSTRACT A mismatch between oxygen availability and metabolic demand may constrain
thermal tolerance. While considerable support for this idea has been found in marine …