I want to see your naturalistic explanation, how it could happen.
So much of it all, everything really, is based on simple positive and negative charges and the amounts of elements available - and time. It all happened on it's own, step by step. (Each step 1 million years)
ATP -
http://simple.wikipedia.org/wiki/Adenosine_triphosphate
- notice how ATP is only oxygen, hydrogen, phosphorus, nitrogen ( the little NH2 - 1 less H than ammonia - sorry, I originally typed alcohol

). The bends in the chain are always carbon, sort of like glue.
Energy in the form of ATP is a requirement for all cellular activities. ATP is produced in the light reactions of photosynthesis.
Photosynthesis can be summarized in the equation:
6H2O (water) + 6CO2(carbon dioxide)------->(using light energy)
-------> 6O2 (oxygen) + C6H12O6 (glucose)
This shows why plants take in carbon dioxide and give off oxygen, also using water and giving off sugars. The little engine of life.
I liked this summary of possible early evolving photosthesis:
The Theme of Evolution in Photosynthesis
Many believe that, early in the Earth's history, microorganisms consumed organic molecules in much the same way that most animals and microorganisms do today. As you might imagine, these ancient organisms ran into a little problem: they were eating away all of the available food but not producing any of their own. (Sounds a little bit familiar, doesn't it? Looks like humans still have a lot in common with microorganisms.) Even though ancient organisms hadn’t even seen a cake yet, they were still trying to have it and eat it, too.
Estimates suggest that photosynthetic organisms appeared on Earth about 3.5 billion years ago.4 The original photosynthetic organisms may have actually used hydrogen sulfide (H2S) as their electron source. Scientists then speculated that cyanobacteria (named for their color) evolved the ability to split a water molecule (H2O), which made the super-strong reducing agents needed for fixing carbon dioxide (CO2) and producing the carbohydrates required for life as we know it. The evolution to water-driven photosynthesis must have required a lot of changes in how organisms at the time conducted photosynthesis. The main reason for the needed changes is that H2O holds onto its electrons a lot better than H2S does. Once organisms figured out how to pull H2O into the reaction, a lot of oxygen (O2) was pumped into the atmosphere, and organic materials began to accumulate on the young Earth.
It's important to point out what is always referred to here - we and everything else are the way we are because these primitive chemical reactions led to this type of reality. We (humans) were not set up, and then these chemical reactions put together by a creator for us. If it happened differently, life would be different. It's interesting how silicone is higher on the amount list from star stuff, and one would predict more silicone involvement in other existences. If you stop and think about stars, sunlight, and the energy systems stars drive and stars use, along with the elements that make up the universe, it is easily possible that the universe is teeming with life. Not humans, but probably mostly amoebas, protozoa, algae type stuff, types of plants, etc. Of course teeming means , I don't know, one planet at the right place every 100 solar systems. Plus, the timing has to be right on the evolutionary path. If you follow space news the amount of known goldilocks zones is increasing quickly.
http://carolguze.com/text/102-8-energymetabolism.shtmlhttp://www.shmoop.com/photosynthesis/evolution.htmledit: alcohol