Animals do not change. Only, humans change. I exist now and I existed 10 years ago. I am the same being. But I am a different being now than I was 10 years ago. No animal has ever said such a thing. The author did not express it this way. The author simply noted the sense observation that, for example, humans used to live in caves and now they live in skyscrapers.
Saying humans are embodied spirits is just another way of saying humans are indefinabilities that become conscious of their own existence. We can comprehend what a human is because we know everything that we do and everything that happens to us. But we can’t define or explicate what a human being is.
The word "level” implies a hierarchy or cardinal system: level 1, level 2, level 3. The human mind has four such levels: observation, inquiry, reflective judgment, deciding what to do with our bodies. The human mind either observes things or asks questions. The human mind does not have a function that lies between observing and asking questions.
The metaphysical definition of self-awareness is that it is the ability to turn in on yourself and catch yourself in the act of your own existence. Defining self-awareness as being able to recognize your self in the mirror is the scientific definition of self-awareness.