I would argue that the main element of comparison in regard to survival between the novel and the 1950s is the way in which the novel presents us with a very clear suggestion of what man must do to survive: adapt. The title of this excellent novel points towards a state of change or of transformation which mankind is undergoing. The way in which the Sealanders are shown to be replacing "normal" men and women in the world and evolving into a different species, and the majority of what the Sealander woman says to David and Rosalind indicates that Wyndham believed humanity had to be open to adapting and evolving itself in order to survive. Note the following example:
The living form defies evolution at its peril; if it does not adapt, it will be broken. The idea of completed man is the supreme vanity: the finished image is a sacrilegious myth.
Arguably this is just as true for the humans in the novel as it is for humans in the context in which he was writing.
I think the second way you can compare survival in the novel and in the 1950s would be looking at the threat of a nuclear holocaust in the 1950s and how the novel presents us with one possible future scenario of what the world could look like after a nuclear war. In a sense, both contexts are about survival, as David and his group of telepaths fight bigotry and narrow-mindedness, and the people in the 1950s are hoping that there will not be a nuclear war that will kill them all.