If vampires were real, what would you say is the scientific explanation for their biology?
For example, what if the reason vampires don't have heartbeats is that their heart-muscles take up an oscillation wave rhythm?
Y'see, get vampires drink blood to sustain themselves, but if they have no pulse it means that the blood they did have in their body will clot. A heart that "waves" instead of "beats" means there is still blood flow but without a detectible rhythm.
Either that or the reason vampires don't have heartbeats is becuse their veins and arteries have no blood to circulate.
Another interesting theory my own mother proposed about vampires is vampires are made of dust. Like being a vampire means you've already decomposed which explains the dry-pastey complexion, but some magic is holding your dust particles in their former place and that that's the reason vampires "turn to dust" when staked or sunlight.
I like to think that being a vampire is a state of "negative life".
+1 Alive