to be honest it'd be something i'd have to think about a little more, but that option makes the most sense to me. i feel it has to do with the brain and not just life. i don't believe plants are 'conscious' even though they're alive. it's more than just physical existence of living cells and organisms. perhaps creatures with more developed brains have a higher level of consciousness too. who knows..
Read up on string theory, you'll never be the same.
I got knocked the fuck out when I was 4, saw some weird shit, when I came to, theory's just gravy
Here comes the math and science...
Something along the lines of 3 dimensions to the 10th dimension, gives you 59049 different states of mind at any given time (at least tangible states, through human cognitivity)
When you go from the 3rd to the 4th, your gonna lose any thought in time, and the 11th dimension is where stupid shit is classified, (the flying spaghetti monster, and his 11 long haired friends...)
So if 4 is to 3 as 11 is to 10, and 11 is fucking stupid, so is 4.
Basically the '4th dimension'(time) is fucking stupid.
metals react to a change in their environment. when they get hot they become pliable, they oxidize and rust, corrode.. just because matter reacts to some sort of external stimulai that doesn't mean that it's self-aware of has any knowledge of it's own existence in the world.
but you go on to say "SENSE a change". do you think plants sense a change, or just react by design? i believe it takes a brain to "sense" these sort of things and it takes a highly developed brain to be self-aware and perhaps have a higher level of consciousness than other creatures.
For example, if you put a dog in front of a mirror, it thinks there's another dog. it doesn't really know that it's actually an image of itself. it just sees another dog. cannot compute. must be a video or something, like seeing a dog on tv. but you take a human or a primate, place them in front of a mirror and they actually see more than just an image. if you were to shine a laser pointer on that primate's head and it saw it in the mirror, it would point to it's own head, indicating that it recognizes that what it sees in the mirror is actually IT. that's not something you can explain. we don't have monkey whisperer's that somehow tell it "hey, that's just you in a reflective glass". it knows. it understands that it exists in this world. that said, i'm sure dogs have some degree of consciousness too. they're alive, they feel, they think, etc etc. but does it really understand and sense it's own existence? that's hard to say. so it must be something about the more highly developed brains that heighten that level of self-awareness.
just my two cents, any way.
"To get high is to forget yourself. And to forget yourself is to see everything else.And to see everything else is to become an understanding molecule in evolution, a conscious tool of the universe" -Jerry Garcia