Yesterday, I argued that we should be thankful for flies, in part because we could have ended up with worse things like flying, carnivorous spiders. Überblogger Tim Eisele commented,
The thing I'm grateful for is that something like starlings haven't evolved into aerial piranha. It would be a real bummer to be walking down the street, minding your own business, and then suddenly have a flock of piranha-starlings descend on you and skeletonize you in five minutes flat.In the office, this led to a lively discussion about such things. Could piranha-starlings prevent Mankind from developing an advanced civilization? More generally, what would happen if the dominant carnivore was fast and omnipresent?
First off, in the case of avius pisces chainsawus, you'd never be able to cross an open field unless you had armor or guns. (Even the guns would be of dubious value.) If you couldn't cross open fields, how would you ever get to the point where you made armor in the first place? Human colonies would have to be mostly underground or in places where there was shelter from the Flying Death. Yes, you could start underground and then move aboveground with buildings, like the malls in Toronto that have covered walkways for Winter use, but that comes with it's own dangers like the easy spread of diseases. In effect, the flying piranhas would channel you into an enclosed spaced where microbes could wipe you out, just like the Cliff Dwellers of the American Southwest.
Chalk up another lucky break for us that God decided to lay off making winged Makita sawsalls.