The Human Form

The psychotechnician Jorun says that his ancestors had lived on the planet Fulkhis for ages and had changed to meet its conditions, further that not a single atom in his own body had originated on Earth before he landed on it. The Terrestrial peasant Kormt replies that it is the form, not the atoms, that matter and that Jorun's form came from Earth. (In fact, Aristotle thought that the soul was the form of the body. See here.)

However, surely changing to meet conditions on Fulkhis involves changing the human form? This will happen even if people are not artificially adapted to other planetary environments as happens in works by Olaf Stapledon and James Blish.

"'...what price the old arguments about sovereignty of form?'"
-James Blish, The Seedling Stars (London, 1972), Book Four, "Watershed," p. 185.

"'...it was also a very old idea on the Earth that basic humanity inheres in the mind, not in the form.'"
-op. cit., p. 191.

Recently, we have quoted Blish's Cities In Flight here, a story in his "Haertel Scholium" here and now his The Seedling Stars in the current post. These are Blish's three bodies of future historical writing.