This stems from the " energy conservation" theory, which suggests that our ancestors might have preserved their energy for essential tasks like hunting and gathering food, rather than spending it on unnecessary activities.

这源于“能量守恒”理论，该理论表明，我们的祖先可能会为狩猎和采集食物等基本任务保存能量，而不是将其花费在不必要的活动上。