I’m curious about the evolution of cold-bloodedness (or warm-bloodedness, whichever evolved from the other).
Does science have any idea when the evolutionary split occurred? What was the evolutionary advantage that gave it survivability? How many changes would be required for a modern animal to evolve to the other (for example, for a lizard to evolve warm-bloodedness)?
Like a lot of things, there’s a trade-off with “warm-bloodedness.” Sustaining a constant internal temperature means keeping all of your chemistry at its optimum performance levels, but the energy needed to do it requires more oxygen and fuel than the alternative.