Richard Matheson dies, aged 87
bbc.co.uk
bbc.co.uk
For those that only know I Am Legend via the film, I definitely recommend reading the book. They don't have much in common apart from zombies and the title.
According to the BBC, the book doesn't even have zombies: "Richard Matheson, who wrote the 1954 vampire novel I Am Legend"
I haven't read the book, so I might be making an unfair judgment here, but I was fairly sure it was about zombies as well.
The book is pretty explicit about them being vampires including distinctly vampiric traits (nocturnal, traditional vampire weaknesses, killing them with stakes through the heart.
The film of the same title, however, rides the line pretty close, coming closer to vampires with the original ending. Their weakness to sunlight and their intelligence are clearly more vampiric, but it doesn't really do much more than that.
Either way, though, Matheson's influence on zombie fiction certainly makes the vampires look more zombie-ish from a modern perspective and can probably be uncontroversially explained at least as a stepping stone from between vampires and zombies.
As for _I am Legend_, _The Last Man on Earth_ was debatably the closest adaptation.