"My understanding of zombie biology is that if you manage to decapitate a zombie then it's dead forever. So perhaps they are being a little over-pessimistic when they conclude that zombies might take over a city in three or four days" - Professor Neil Ferguson, Imperial College London
Science ponders "Zombie attacks" (BBC). It sounds wacky but apparently it can help scientists understanding virus pandemics. I knew my good friend M. (an international expert on infectious diseases) would eventually come up with a really good explanation for his zombie film collection.