How did a group of animals completely reorganize its physiology to go from mesothermic to endothermic?

一群动物如何完全重组其生理机能，从温热状态转变为吸热状态？

Animals like this, that control their body temperature in a variety of ways, are mesothermic, and today they're pretty rare.

像这样以多种方式控制体温的动物是恒温动物，如今它们非常罕见。

Which makes sense, because many large sharks today are mesothermic – they can keep their bodies a little warmer than the surrounding water temperature, which helps them stay active even in colder waters.

这很有道理，因为今天许多大型鲨鱼都是中温性的——它们能够保持身体的温度比周围水温略高，这帮助它们即使在冷水中也能保持活跃。