An example of this would be the current trend regarding obesity.
a model to test the industrial flight hypothesis
As scientists know with mammals, although , it comes with a great energetic cost. As with plants, an animal can spend its on consumption (metabolism) or investment (growth). An intriguing hypothesis is that growing large was part of an energy strategy, as the benefits of size (reduced risk of predation, ease of conserving body heat and consequently less need for a high metabolism, ability to access new food sources, such as foliage high above the ground) outweighed their costs (energy devoted to growth instead of metabolism, the need to constantly feed). Their size and the warm climate meant that large dinosaurs did not need as intense internal energy generation as mammals do, for instance, and dinosaurs may have been , with internal energy regulation greater than , but not as great as (mammals and birds).
Trade and The Industrial Flight Hypothesis.
The issue of avian and dinosaurian air sacs and when they evolved has been the focus of a rancorous dispute that was only recently resolved and hinged on the hollow parts of bones, which is a phenomenon called . The controversy involved dinosaur bone pneumaticity and how it may have been related to birds. In a , it was shown that birds have their most important air sacs where nobody thought they were, near a bird’s tail, not its head. Not only that, pneumatic bones are all related to the air sac system, and birds have the same pneumatic bones as saurischian dinosaurs did. The obvious implication is that the air sac system evolved in theropods and sauropods, when dinosaurs first appeared. If the air sac system appeared with the first dinosaurs, it is one more big reason why dinosaurs prevailed over the less respiratorily gifted therapsids. Such a highly effective respiration system evolving in a low-oxygen environment is a tantalizing hypothesis.