Sometimes I wonder how so much complexity and co-dependency has evolved on earth in such little time. Most estimates I've read say that we're likely within an order of magnitude of 100 trillion generations deep from the universal common ancestor at this point. That sounds like a lot, but not really. If you took 30 four sided die, you'd have to roll them a million trillion times to have a good shot at getting any specific permutation.

How many 'die rolls' does it take to get a selective feature to emerge in an organism? If you do a google image search for 'camouflage bugs', you'll find some brain-bending examples. There's clearly a selective advantage for some of those 'configurations', but how many generations would it take for each genetic mutation required to make a lichen katydid or an orchid mantis to converge?