Body Size and Tracheal Function in Insects

虽然大气成分通常被认为是一个常数，但最近的研究表明，大气中的氧和二氧化碳浓度有很大的变化。特别是，地质研究表明，古生代晚期的巨型昆虫恰好与大气中的氧气含量超过今天的水平至少50%相吻合，这使得人们认为，巨大的昆虫可能是由于更充足的氧气而产生的。这在逻辑上导致了这样一个命题，即当今昆虫的体型受到大气中氧气供应的限制。这项研究将检验这一假设的预测。具体来说，将测试昆虫体内供氧安全边际随着体型增大而减小的可能性。实验将以美洲蝗虫为模型进行，因为这种昆虫：(1)成年后的体型很大，(2)在发育过程中体型变化很大，(3)呼吸生理学研究得很好。

9728444 Harrison While atmospheric composition has often been considered to be a constant, recent studies have demonstrated that atmospheric oxygen and carbon dioxide concentrations have varied substantially. In particular, geologic studies have suggested that the giant insects of the late Paleozoic coincided with atmospheric oxygen levels which exceed today's levels by at least 50%, leading to the suggestion that giant insects may have been made possible by this greater availability of oxygen. This leads logically to the proposition that the body size of today's insects are limited by atmospheric oxygen availability. This research will test predictions from this hypothesis. Specifically, the possibility that the safety margin for oxygen delivery decreases with increasing body size in insects will be tested. The experiments will be conducted using the American locust as models, because this insect: (1) reaches a large adult size, (2) varies widely in body size during development, and (3) has a well-studied respiratory physiology.