http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2812825/pdf/ijms-10-03420.pdf
"Abstract: A number of small RNA sequences, located in different non-coding sequences
and highly preserved across the tree of life, have been suggested to be molecular fossils, of
ancient (and possibly primordial) origin."
So they assume since this RNA are highly preserved across the tree then it must be ancient , thus in the beginning. This reasoning also applies to other highly preserved part of life, for example ATP Synthase. There is no physical life known to man that doesn't require ATP Synthase (which scientist are learning more all the time just how complex this machine is).
Living cells without ATP Synthase is like a gasoline engine car with no gas. So even if you had all the part ot build a cell they would be totally worthless without fuel. The only known way for nature to produce ATP is by ATP Synthase which happen to only be produced by living cells.
Conclusion: there has to be life outside the known realm of science, some put their faith in a nature god (mini-god) while some put faith in a spiritual one.
