  I show that exoplanets can be used to test origins scenarios. Origins
scenarios start with certain initial conditions, proceed via a network of
chemical reactions and, if successful, result in a chemistry that is closer to
a living system than the initial conditions. Exoplanet environments can be
applied to test each of these three aspects of origins scenarios. I show what
tests can be applied to the UV-driven cyanosulfidic scenario and how the
application of some of these tests has already falsified certain versions of
this scenario. Testing initial conditions has replaced certain reactants with
others and has affected the overall chemical network underlying the
cyanosulfidic scenario. The sequence of reactions the scenario invokes provide
a predicted upper limit on the ubiquity of life in the universe that has ample
room for improvement. The outcome of the experiments in different environments
is part of a predicted distribution of biosignature detections that can be
compared to future observed distributions.
