are we alone in the universe?

[Alan Anderson]

Originally Posted by KenWittlief

it becomes a chicken/egg problem. DNA based single cell organisms can take oxygen, carbon, hydrogen... and build its own amino acids, its own protien strands, and create a complete perfect copy of itself

but anything less than that one cell organism cant - cant build any of the molecules needed

Viruses reproduce just fine with only a fraction of the complexity of a full-blown cell. They can't do it without the proper conditions, but given the appropriate environment they manage. Mitochondria are an interesting example as well, as they appear to be genetically distinct from the cells they inhabit.

Amino acids are easily created in the laboratory using chemicals and processes intended to mimic the young Earth's environment. Some of them combine on their own to form peptides, and given enough time there's a nonzero probability that relatively complex molecules will arise just from random mixing. Hundreds of thousands of years of such mixing is going to yield a lot of potential precursors to life as we know it using non-living processes. It's not much of a stretch to imagine a short chain of RNA that spontaneously duplicates in the presence of the right mix of amino acids.

Why don't we see this happening in the laboratory, or the wild, now? In the lab, there arguably hasn't been enough time for it to occur at random. In the wild, the environment is no longer amenable to such processes.