These are the definitions of the Drake Equation: R* = the average rate of star formation in our galaxy fp = the fraction of those stars that have planets

These are the definitions of the Drake Equation: R* = the average rate of star formation in our galaxy fp = the fraction of those stars that have planets ne = the average number of planets that can potentially support life per star that has planets fl = the fraction of planets that could support life that actually develop life at some point fi = the fraction of planets with life that actually go on to develop intelligent life (civilizations) fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space L = the length of time for which such civilizations release detectable signals into space[8][9] I think the most interesting thing is as a sort of a map of human knowledge. Fill in the blanks with your best answer at this point. We know some stuff about some of these, but very little about others. I think we can make sensible guesses at the first three, and the last two and Drake's Equation allows us a large margin of error. The likelihood of life developing and the likelihood of intelligence developing however… we don't have much. A weird thing about both these things is that we are the only example we know of. Even earth, which has demonstrated an ability to develop both, seems to have done both only once. All life on earth shares an ancestry. Intelligence is debatable, but by a definition that carries the potential to build technology proving its intelligence to extra terrestrials we are the only example. We can be reasonably certain that if we start from Eukaryotic life, eyes will evolve. Technology building and intergenerational knowledge accumulation is less certain. Even if you start with humans, it's not obvious that technology will evolve. Homo existed for quite a while, even with individuals very similar to us before getting on this technology curve. Thousands of generations (or tends of thousands, depending on your definitions) of being smart, social bipedal apes anatomically similar to us with no apparent evidence that the invention of pornography-capable smartphones are forthcoming. We have similarly little evidence about life's chances of emerging. Some sort of replication process that has evolutionary potential would be a decent definition in this context. How likely is that? Do we actually need the "ingredients" common to Europa and Earth? Is Earth's "ingredient list" even ideal? Is organic chemistry the only way to do things? I think our ongoing invention of complex machines is, perhaps, a counterexample. Back to the Drake equation, I think any time we can fill in one of the variables, tighten up our margins of error or otherwise add knowledge to this knowledge map, we are making interesting progress. TLDR: At this point in time the existence of both life and intelligence must be assumed to involve ancient, god-like extraterrestrials.