How is the theme of evolution approached in Ubik?

A major theme in the novel, Ubik, is evolution. Joe Chip addresses evolution in the early chapters when he explains to Pat why people have developed anti-telepathy. He says one insect learns to fly and another insect learns to build a web to catch them, and these relationships are everywhere in life to counteract potential problems. So when telepaths evolved, anti-telepaths evolved soon after.

With this in mind, Jory attempts to go against evolution by regressing the world back to 1939. Suddenly the characters find themselves completely at odds with their environment. Dick highlights this when Joe is talking to Mr Bliss about the upcoming second world war. Mr. Bliss talks about what he calls the nigger problem and how not all of what Hitler says is wrong. Joe had never heard such attitudes before and feels uncomfortable. He thinks to himself that he could have coped with the world going back 10 or 20 years, but to go back this far is likely to cause him and the others major problems psychologically. This theory proved correct by the way Jory takes advantage of the character's confusion. In particular, Pat's delusions of grandeur are out of place. However, Joe's earlier statement that humans evolve in order to survive, proves correct when he increasingly adapts to his surroundings until he is no longer in fear for his life.