why somes species don’t have their own body heat (like reptiles) and rely on the environment’s temperature when the combustion of sugar in the blood releases energy and heat (and allows us to have our own body temperature)?

Question

why somes species don’t have their own body heat (like reptiles) and rely on the environment’s temperature when the combustion of sugar in the blood releases energy and heat (and allows us to have our own body temperature)?

In: Biology

Answer 1

This is basically asking why some animals are more evolved/specialized than others. It’s just how we developed over time.

Cold blooded animals live in environments that they thrive in, and having to regulate their own temperature would cost way too much energy that wouldn’t be as “fit” in that environment. For example a reptile living in the desert would not benefit from being forced to ingest copious amounts of water + food to regulate their own temperature. That amount of food and water doesn’t exist in that environment, and so it would be disadvantageous to develop those traits.