Rick, I love your posts in this thread! So true about the inter-dependence, and we're (that is, the human race, not us ATPers in particular) only scratching the surface in understanding all the dependencies and interactions in a system as complex yet commonplace as soil or natural waters.
Since you mentioned rock, ice, and toxic waste... there are microbial communities in all of them! Concrete is the only one you listed I'm not sure about, but I know people who study and culture microbes from all of those other places, and some that are even less hospitable to life as we know it. Hydrothermal vents, for example, have temperature (3x the boiling point of water), pressure (50x what would kill a human), energy (no sun to fuel things), and chemical (toxic sulfides, heavy metals) conditions that would make it impossible for most organisms to survive a moment - but they're teeming with life! It was recently discovered that there are fungi in the solid bedrock under the deep ocean, previously thought to be inhabitable only by Bacteria and their less-well-known cousins Archaea. Polar ice can contain large amounts of algae - tiny plants that photosynthesize from inside their chilly prisons. Life really is amazing.
Arlene, not sure if you know this or not, but there are two icons at the bottom each post - a star and a thumbs-up. If you click either of them on your favorite post with lots of good info, you'll get a link in your profile so you can find it again easily. I'm not entirely clear on the difference between the two - I think perhaps only you can see your stars, whereas the thumbs-ups have a little number by them to let other people know you like a post.
