We know essentially nothing about life beyond Earth. Because we are ignorant of other biological systems, we have no context for understanding Earth life, for knowing to what extent the life we see around us is, on the cosmic scale, relatively ordinary or totally freakish. We don't know, for example, if Earthlike planets are common. We look around our own solar system, and what appears to be common are planets that have no life whatsoever. We also see signs that Venus and Mars were once more hospitable to life and over many hundreds of millions of years became inhospitable.
Bad stuff happens to good planets.
It'd be nice to know more about that trend. The debate in Kansas over the teaching of evolution misses the real debates within the field. There are those who argue passionately that life originated with a single replicated molecule. Another camp favors the notion that it began with a kind of garbage bag of molecules that more or less eased its way from nonlife to life. And the biggest question may be to what extent evolution is divergent or convergent.