I've always wondered what the earth would like to do with the skyscraper thickets we build--if it had its way. Today's mega-flora of glass and steel begs the question, 'Where are the mega-fauna to go with?'
We've consumed the earth's surface with a lunatic building spree. Nature has not quite caught up yet. The pigeons, rats, cockroaches, and doppelgangers have already moved in. They aren't picky sorts, willing to pick through scraps and garbage heaps to make the best of things. The coyotes and hawks are moving in, though. We built this jungle with the idea that we, humans, would be its apex predator. King of the concrete hill. Perhaps that was true, and will be true for a while longer. The arrival of zombie dogs in our habitat should perhaps be viewed as a harbinger of things to come, however. (Do a google search of the term if the link doesn't work for you and you don't believe me.) We may not remain at the top of the pyramid much longer.
Rogue biologists may soon seek to re-inject biodiversity into our cities. If they don't do it, the earth itself has a few evolutionary tricks up its sleeves. And I do look forward to it.
I look forward to the days when Parking-spotted beasts wait patiently on the macadam to devour the unwary Intrepid, when feral sidewalk gnomes harvest the flesh of muggers, and a variety of flying beasties hunt snatch the occasional CEO from his penthouse balcony. I think of balances restored, and humanity returned to its natural place as just one of many diverse dangerous creatures to walk the earth.