> ie. The brain is not necessarily a pre-requisite for consciousness.

I'm not saying brains are the only way to produce consciousness, just that the evidence shows that they are the way animals do here on Earth.

It is extremely unlikely that there is something else involved.

> There is certainly much of physics remaining to be discovered, but in the specific regime covering the particles and forces that make up human beings and their environments, we have good reason to think that all of the ingredients and their dynamics are understood to extremely high precision (Carroll 2021a). Modern physics, in other words, provides evidence for what philosophers call “causal closure of the physical”: physical events have purely physical causes (Loewer 1995, Papineau 1995), at least in the regime relevant to human life. Without dramatically upending our understanding of quantum field theory, there is no room for any new influences that could bear on the problem of consciousness.

https://philpapers.org/archive/CARCAT-33.pdf

(author is now Homewood Professor of Natural Philosophy at Johns Hopkins)