Thanks and +1 on Kelnet and Bucko....smart people.....and others too of course. Yes, we've been to the brink and back a few times...most often, I'm afraid, thanks to me probably. It's wild the shifting directions things take in a thread that lasts awhile. I was hoping for a bit of an interesting tussle of ideas but I would never have predicted all this. The mods have shown some amazing restraint and patience that has lead to it's life span and I'd like to acknowledge that. Yeah, lots of factors. In biology they have a concept called 'requisite variety'. One way to express what it means is the organism that has the greatest variety of behaviours will dominate it's environment. I think that observation goes a long way to explaining how we're still here. It also explains how one small child can be in charge of two parents.