Dan Janzen on a future DNA reader

Dan Janzen imagines a handheld DNA reader in the near future which when inputted with any part of an animal (leg, scat, saliva) could tell you the species from whence it came.

For instance, dip it in a river and see what kinds of frogs and fish live upstream. Or give it a feather and see what bird has been flying by. Or lick it and see if you're coughing on account of the common cold or Ebola.