In a way this explanation sort of makes sense. I can see that Natural Selection would tend to direct life into forms that in one way or another are energy efficient. Being energy efficient means that the life form can live, and have children, with as little food intake as possible. So a life form that is less energy efficient would tend to have fewer offspring. Therefore low energy efficiency would tend to be selected out. The result would be that most life forms would evolve to be as energy efficient as possible. There would have to be a balance between energy efficiency and the activities that gather the energy. I could see that there might be a sort of a balance point there that would turn out to be the same for all life forms.
It does seem to me that if a life form develops some characteristic that is less energy efficient, but confers some other positive benefit it may still be selected. I'm not sure just what that would entail. It's possible that this would produce a brief surge in the species which would then be worked out to restore the 'normal' energy efficiency.
Bill, How the tiger loses the excess heat isn't really what they are talking about. They are addressing the overall energy balance of whatever life form they study.
Bill Gill
