A soup to nuts history of life, humanity and consciousness.
LeDoux rightly roots his account of life in the territory of complexity. He points out that the increasing complexity of organisms gave rise to the problem of control. If an organism can do many different things, how are those things or behaviours prioritised and/or coordinated? Nervous systems are the answer. Complexity continues to increase until another new evolutionary step pops up. This is the ability to form mental representations, based on memories, that guide behaviour. When one of these connects with the relevant stimulus, the result emerges in consciousness. Thus, his theory is a variation of the higher-order theory of consciousness.
You might also like to browse other evolution posts: https://www.thesentientrobot.com/category/evolution/