I only have a few minutes before joining with some old friends for a night of teleconferencing and a virtual board game, so this is just a quick post... This evening, Firefox' home page dished up an article which I might not necessarily agree with, but which is an interesting intellectual exercise: Do we share the planet with currently recognizable life forms? Such lifeforms, with a different biochemistry, alien to us, and therefore undetectable using current investigative techniques, would form a sort of 'shadow biosphere'. The concept, which I don't necessarily buy, reminds me of dark matter, for which there is evidence, but little interaction (besides gravitational forces).
Me being a smartass, I was reminded of this oldie:
It's a thought-provoking read, even if I don't necessarily buy it- an interesting intellectual exercise... and, hey, further inquiries could open up biological vistas previously unsuspected. I shall be pondering it even as I engage in contention with my old chums.