How does a plant grow just on water and sunlight and oxygen?
I contend - that all species, beyond the fundamental atomic building blocks (carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur etc.) need only two of four fuel and energy sources in order to live, grow, sustain ones self, and thrive. They are water, sunlight, oxygen and any saccharide (any sugar molecule - starches etc.).
Aeroponics shows that a soil medium is not necessary but still many practice with a "nutrient spray". If you used twice distilled water and no nutrients it would still work. I've done that.
It is an intriguing idea that something comes from nothing - that one cell or molecule, or protein or amino acids say can begat another of same (or similar?). We know of cell division which doesn't have to make sense yet it happens, but how do mineral components multiply? Or do they?
How does an avocado seed planted in nothing but pure water, sitting in the sun - grow? Yes, the seed has 'stored nutrients' that can or may be distributed - but one, does the seed lose it's mass by dispensing it's nutrients after 6 months or whenever the leaves are a foot or two tall, does the seed itself still have the same amount of whatever nutrients it started with- and two, how did the leaf furthest away from the seed or root, manage to have minerals and vitamins, and proteins and amino acids in it?
One has to assume that the overall weight, mass and volume of the entire organic entity, seed and plant, has increased, possibly doubled even tripled in size (mass, volume, weight etc.).
Did the nutrient components increase in numbers and or amounts or size (of course an amino acid doesn't grow...)? Where did they come from how did they get there on their own without any interaction with anything other than sunlight, oxygen and water - and the forth essential element I mentioned, a sugar component, the sun takes care of that? Can the sun take care of a few other things like D or C - how did Vitamin C get into the top leaf of that avocado plant?