The "idea" of an organism isn't ambiguous. It is analogous to the word "life".
I don't think so. A virus is a form of life, but it is not a living organism. Living organisms must be able to reproduce without invading and corrupting the DNA/RNA of other living organisms to get the job done.
Regarding the Gaia hypothesis: It is more literary spin than scientific fact. My F-150 might qualify as a "living organism" using Gaia criteria.
"Life" doesn't exist as a single organism within the context it is being looked at by most - therefore it cannot be defined by single metric. The concept that "life" is actually a single organism, that which is contained within the closed system upon this planet, is a far easier perspective to define the word "life" within. That is probably the only way you will get the simple word to actually fit what it is trying to define. For everything else, we will have to look at them for their specifics; i.e. is it a single-cell organism, multi-cellular organism, virus, or simply chemical element such as oxygen, iron, manganese, etc etc.... FWIW, look at the diversity of interaction an oxygen atom can experience on this planet - it could be argued that even the simple atom itself is alive - it certainly behaves in predictable as well as unpredictable ways dependent on circumstance, so, wouldn't it be just as alive as anything else?
I don't follow this very well. Life is what's alive, isn't it? Can you crush the life out of an ant? And when you look at the smudge on the sidewalk is their still an organism there? Yes, there is; a dead one.
One way to describe "life" is the extant function of genetic code. Without it, an organism would be a blob of uninformed chemicals. And not only does it inform living organisms but it also jumps into their offspring for trans-generational survival. Genes can do that because they're digital.
Even the suggestion that there was some extra-terrestrial influence on the early earth which led to what we have agreed on is "living" would still conform to the concept of a "universe" - afterall, how can it be called a "universe" if it isn't universal? Better stated, how can an exception be made? We all agree that probability is equally distributed troughout the universe, right?
This statement seems to verge toward panspermiaâ€”the idea that life originated extraterrestrially and was contagious enough to contaminate Earth (although panspermia would also allow for the extraterrestrial spread of Earth-first life). I happen to prefer panspermia over Earth-first life as a way of explaining life's appearance on Earth. Panspermia does not explain life's origin, of course; it just defers it to the possibility that somewhere else besides Earth was the host of nascent life.
For us to expect that life originated first on Earth is a huge and precarious assumption. It reminds me of the old geocentric-universe model. Humans have a history of being arrogated snobs in that department.
But you are asking good questions. I doubt that either of us will live long to see the definitive answer to the question: How did nature originally turn abiotic matter into the first biotic material? Or, put a simpler way, what where the physicochemical steps to abiogenesis and why were they exclusive to Earth?
It doesn't appear to me that all of this just happened either - for this one particular observation of what the universe has been doing all this time.
It is the "just happened" part of your statement that bothers me. I think you are assuming that things that "just happen" are somehow planned by a Cosmic Designer, let us say. This is the core fallacy of the ID movementâ€”that since we don't always understand how nature proceeds from moment to moment then sometimes things "just happen." And, of course, that is attributed to the Cosmic Designer's purpose, whatever It may be.
Once upon a time humans didn't understand nature well enough to know about the galaxy they lived in, and so they reasoned to the best of their ability that some god up there poured milk across the sky.
I Can't speak for if life exists anywhere else in the universe though - it is likely not to be structured with the same DNA construct as here - the universe is just too diverse.
One thing that has always interested me is the fact that there is only one kind of life on Earthâ€”DNA/RNA life. Some people say that DNA/RNA life might have eaten any other nascent kinds into extinction, so that's why there is only one kind left for us to observe. I disagree with that notion because planet Earth seems (to me, at least) to offer a rich enough and diverse enough biosphere that it should have nooks and crannies somewhere to support non-DNA/RNA life. But there is none. This leads me to doubt that "life" in other places of the universe will be anything other than DNA/RNA life.
But it's a great question, and clues are not yet very helpful.
Perhaps my observation of the structure of the universe moving towards more diverse structures is entropy itself? The definition of entropy doesn't have explicit context when it comes to how entropy affects diversity - it only speaks in terms of order vs. disorder. So, is the movement towards greater diversity a movement towards more or less order? Or, more specifically, is "order" equivalent to less diversity while "disorder" is equivalent to more diversity?
It's hard to avoid the term "complexity" when discussing these matters. But let me suggest that thermodynamic equilibrium may not rule the universe. There are such things as "dissipative structures," according to Ilya Prigogine, that organize and complexify under conditions "far from equilibrium." And they do this with some heightened state of entropy production. For a clumsy example, take the hula hoop. At thermodynamic equilibrium the hula hoop lays motionless around your feet and produces no kinetic order or entropy dissipation. But if you were to rotate it around your waist it would achieve kinetic order in the form of an oscillating orbit. It takes energy input and entropy production to make that dissipative structure do its orbiting thing. (But there is a flaw in my example: living dissipative structures are not suppose to be reversible back and forth between ordered kinetics and thermodynamic equilibrium. In living organisms that would invoke "death."
I am only working from the diction-definitions of words we are using to have this conversation. It is just difficult to think that the rise of self-awareness we humans possess is actually a result of increased "disorder" within the universe. Was "awareness" actually the next "step" in cosmological diversity? Taking the next step from there, are our abilities to change the universe as said "aware" beings the current step the universe is perched upon? Kindof hard to say "no" to those questions, isn't it? Isn't that exactly what is happening?
It's hard to understand how we have become aware of our awareness. We call it "consciousness," and yet we don't really know what that means. My own worry is that human arrogance clouds the issue. "If you're a hammer the world looks like a nail." Something is too recursive for us manage when we examine the meaning of awareness. It is befuddled partly by the anthropic principle or some other paradox that leaves you reasoning with yourself in the mirror.