Suppose twenty million years from now there are very large flying insects inhabiting Earth.What is the most likely atmospheric change that has occurred?

Question

Quizplus · Accepted Answer

Insects are limited in size by their respiratory system, as they breathe through tiny tubes called tracheae. The higher the oxygen concentration in the air, the easier it is for insects to breathe and grow larger. Therefore, an increase in the oxygen concentration would be the most likely atmospheric change to enable the evolution of very large flying insects.

Suppose Twenty Million Years from Now There Are Very Large