Steven Spielberg only uses two direct quotes from H.G. Wells' novel, one from the opening and one from the closing. I was surprised to see that he kept the story in the movie pretty much consistent with that of the novel; it suggests that the scientific paradigm dominant in H.G. Wells' day (the novel was first published in 1898) is still pretty much intact, at least with regards to biology.
Here the opening paragraph of H.G. Wells' The War of the Worlds:
No one would have believed in the last years of the nineteenth century that this world was being watched keenly and closely by intelligences greater than man's and yet as mortal as his own; that as men busied themselves about their various concerns they were scrutinised and studied, perhaps almost as narrowly as a man with a microscope might scrutinise the transient creatures that swarm and multiply in a drop of water. With infinite complacency men went to and fro over this globe about their little affairs, serene in their assurance of their empire over matter. It is possible that the infusoria under the microscope do the same. No one gave a thought to the older worlds of space as sources of human danger, or thought of them only to dismiss the idea of life upon them as impossible or improbable. It is curious to recall some of the mental habits of those departed days. At most terrestrial men fancied there might be other men upon Mars, perhaps inferior to themselves and ready to welcome a missionary enterprise. Yet across the gulf of space, minds that are to our minds as ours are to those of the beasts that perish, intellects vast and cool and unsympathetic, regarded this earth with envious eyes, and slowly and surely drew their plans against us. And early in the twentieth century came the great disillusionment.
And here is the paragraph quoted from the end of the novel:
For so it had come about, as indeed I and many men might have foreseen had not terror and disaster blinded our minds. These germs of disease have taken toll of humanity since the beginning of things--taken toll of our prehuman ancestors since life began here. But by virtue of this natural selection of our kind we have developed resisting power; to no germs do we succumb without a struggle, and to many--those that cause putrefaction in dead matter, for instance--our living frames are altogether immune. But there are no bacteria in Mars, and directly these invaders arrived, directly they drank and fed, our microscopic allies began to work their overthrow. Already when I watched them they were irrevocably doomed, dying and rotting even as they went to and fro. It was inevitable. By the toll of a billion deaths man has bought his birthright of the earth, and it is his against all comers; it would still be his were the Martians ten times as mighty as they are. For neither do men live nor die in vain.
Judging from Spielberg's approach to the ending of the movie, evolution and antibodies are still generally interesting biological concepts.
Then again, I overheard a number of people walking out of the theater confused about what exactly killed the aliens -- so maybe many people still don't really get the idea of resistance to bacteria. And quite a number of other people seem to think the ending to the film "sucks." So maybe Wells' concepts are either so obvious that they're no longer interesting... or people still don't get the basic concepts of biology.
The full text of The War of the Worlds is available as an etext at Project Gutenberg here.