Could an alien underground macroscopic ecosystem including human sized plant-like organisms evolve around lava as an energy source? These organisms could use heat and/or light from the lava to synthesize organic molecules. Would these organisms favor a particular shape? Would they be more likely to hang from ceilings than to grow from the ground? Could the presence of anything in the environment encourage this, such as reflective elements? Assume life could have evolved on the planet's surface originally or simultaneously.
It seems like this would encounter a number of problems such as:
- As calculated in this post, lava gives off very strong light, and humans at least have to be no closer than around 8 or 10 meters and at a sharp angle from the surface of the lava.
- Lava needing to have a constant relatively unchanged presence that could reasonably be adapted to across evolutionary time spans. What could prevent the lava from cooling that would also keep it in the same place and allow organisms to thrive?
- How quickly energy could attenuate from the lava source, this could force life into tighter spaces than other cave environments?
- The organisms might need a heat potential across which to do work. This could maybe take the form of cool hollow shafts in the rock to expel heat with, or the plants prefer to grow around corners or towards the energy source so that further back parts of the organism are cooler?