"Consciousness is the biggest problem for materialism. How is it possible that a bunch of particles that are devoid of consciousness get together and cause consciousness?"

Consciousness is an "emergent property" of the brain, meaning it arises from the complex interactions of its components (neurons) but is not reducible to those individual components or their properties. It's not a single thing that resides in a specific area, but rather a property that emerges from the coordinated activity of the entire brain.

A classic example is water, which is wet, but its constituent elements, hydrogen and oxygen, are not.

Though personally I prefer the example of Life itself. Which seems to an emergent property of other emergent systems and of the universe itself.

I don't think the universe was "tuned" but we are the natural outcome of the of the laws and rules of evolution of this universe. Which is most likely one of an infinite number of possible universes.

If it was "tuned" somehow then right there is your God of the gaps. The final gap. It's much more likely though that we are just one of many possible universes. As our consciousness expands out into this universe we have become aware of how big space and time really is and the possibilities of more universes and dimensions we cannot see (yet) get bigger. And the Gods get smaller.

Throughout history, our understanding of the universe has evolved dramatically, moving from a perception of a flat Earth at the center to our current understanding of an expanding cosmos filled with galaxies beyond measure.

I don't expect it to stop here. Unless we enter another dark age.

"some theories propose that consciousness might be fundamental, with the physical world potentially being a manifestation of consciousness."

Define "some". Regardless I don't disagree. It's a matter of perception. Depending on how you define consciousness.

But the "consciousness" of a rock is not the same as the consciousness achievable in a brain. And the brain is the result of evolution. The evolution of the universe. And that evolution is still ongoing.

As for whether consciousness is fundamental again it's perception ... what do to mean by that? So do you mean you think consciousness always existed? It pervades all matter at the quantum level?

With that I'd have to disagree. Without the emergent property of Life the emergent property of consciousness was not possible. Just as the emergent property of water was not possible until hydrogen could combine with oxygen. And at one point during the evolution of the universe oxygen did not exist and water was not possible.

Just as at one point Life did not exist and consciousness was not possible.

Understanding the quantum nature of the universe is not for the weak minded.

I recommend anything by professor Sean Carol or Brian Greene. Sean Carol can go as deep into the math as you can handle or he can keep it light and go over the fundamentals of quantum mechanics to give you an over view. Brian has a great way of explaining things.

A word of warning tho.. It's been said (by Richard Feynman), "I think I can safely say that nobody understands quantum mechanics."

And I think that is still true. Which means nobody really understands the fundamental nature of the Universe. (Yet)

But I do know this to be true from personal experience(which I also admit is not infallible). Nothing Matters. A lot!

"Consciousness is defined as self awareness."

Where does consciousness exist? Can you point to it? I always point to my brain. Because you can't point to it without a brain. Some actually point to their hearts or whatever it is they are currently looking at. The Greeks believed it was in your heart or whatever they called "thumus".

Does our consciousness only exist in our brains or does it go out and "touch" things? It's my understanding that we recreate the world inside our brains. It doesn't really look like how we recreate it at all. Because our senses are like filters. They filter out the things we don't need for the immediate survival of our genes. There is an inside world that is a recreation of the outside world. But not an exact copy. Which is why some concepts (like the earth spinning and revolving around the sun) have been difficult for us as humans because we create an illusion so that we can deal with the universe on the macro level that we exist in. We live in an illusion our brains create. Some live in illusions that are stronger that others. Obviously.

If Something (Matter/Energy) can come from Nothing. (Whether by a God or the Natural Evolution of Universes or whatever you choose to call it)

Then Nothing definitely Matters.

A lot!