A man and his family arrive on Mars to escape the wars on Earth. Slowly, things begin to change which causes Harry to be fearful. It takes him much longer than the others to embrace the change and feel safe in his new home.
Technology and progress could lead to the end of human cicilization
"The wind blew as if to flake away their identities"
"Dark They Were and Golden-Eyed"
"Cora, these blossoms!"She handled them."Do you see? The're different. They've changed! They're not peach blossoms any more!"
The earth people do not realize they are losing their humanity
"Doesn't it scare you?""Can't recall that it did much, Harry."
What matters most is that the people weren't scared of the change.
This shows us that Harry is afraid of the changes.
This shows us that Harry's neighbors didn't really care about the change.