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)

On some views, the brain may be a particularly complex organisation, localisation, or exemplar of consciousness, rather than its ultimate origin. That would include any brains here on earth.

It is extremely unlikely that there is something else involved.

Well, that's clearly a view to be expected of a hardcore physicalist like Carroll but the quoted text seems somewhat circular as it insists on a framework that seems not to really get to grips with the Hard Problem.

This kind of intellectual arrogance and blindness is exactly how people believed that the earth is the center of the universe, and that only human beings have souls. There is nothing new to be learned from their dogmatic opinions.