You may have your own opinions on the between the lines meaning of zombies movies. That they may reflect the consumerist nature of our society and that the spread of the zombie virus is similar to the effects of viral marketing. This post is not about that... in fact it is about the evolution of the zombies in zombie movies that I have noticed since... well, the day I started watching zombie movies.
Here is what I have noticed:
1) Zombies were the dead brought to life by Magic or Voodoo, once upon a time
This was of course based on the West African legend that a corpse can be brought back to life by a witch doctor or sorcerer. Apparently even the word Zombie came from the word Nzambi which means 'god'. Stating that the corpse was more like a Evil vampire god rather than a mindless automaton of flesh.
And the Movie the Evil Dead was the movie based on my recollection that stayed true to this mythological portrayal of the Undead.
2)Zombies then evolved to the product of a virus
The ever popular mode of resurrection. It's so easy to say some secret experiment had caused the world to become mindless eating machines because we know how viruses can evolve and that there is so much still yet to be discovered in the world of viruses. Making the perfect believable cliche´.
This concept apparently started off in such movies as Night of the living dead, Dawn of the dead and other zombie movies of the 80's. So from mythological magic to contagious viruses.
Oh yeah Hollywood also borrowed the contagious bite from Vampires and Werewolves. So it's triumvirate now of contagious evil,because it is so much cooler to know that you too can be evil willingly... or unwillingly.
3)Zombies are smarter
A concept explored a bit in Dawn of the Dead was that zombies retained memories from their living past. Thus making them a more cunning enemy. As well Zombies no longer attack at random but do so in groups proving that two heads (or a million heads) are better than one.
4) Zombies can run!!!!
That's right Zombies are not only smarter but they can run! No longer are they limited to lumbering slowly towards you in hopes that you will be dumb enough not to notice a rotting corpse walk towards wanting to slurp on some brain matter. They not only run but because they feel no pain they run like an Olympic 100 meter dash runner all day long!!
This concept was first introduced based on my movie knowledge in 28 Days Later. Where the zombies were not only hungry... but pissed off!! Excuse my American lingo.
This variant of the zombie, the fast running,cunning and amazingly angry Zombie is so popular that even the Resident Evil Franchise which was based on a video game (also known as Biohazard in Japan) which originally had the slow zombie turned their zombies into the fast ones. I mean do remember just running through the Zombies when you ran out of Ammo? or at least saving your machine gun and shotgun rounds for the final boss? Yup those were the original resident evil zombies. The fastest it ever moved was when i was less that an inch away from you and it toppled over like Old Man river slipping on a rock trying to grab you.
In conclusion, (really? does this post need one?) I think in terms of filming time and for creating Drama sake, The fast moving Zombie has become the final incarnation of Zombies so far. Thus making everything seem on a daggers edge and that the heroes just barely survived. If you ask me which one I like? Of course the fast Zombies!! It makes playing Left 4 Dead a heck of a lot cooler :D Although if a Zombiocolypse ever happens... I'd like the slower dumb ones...and a shotgun.