The Human Form II

See The Human Form.

There has indeed been artificial adaptation of human beings to diverse planetary environments in the far future of "The Chapter Ends":

"...man had changed; over the thousands of years, natural and controlled adaptation had fitted him to the worlds he had colonized, and most of his many races could not now feel at home [on Earth]."
-Poul Anderson, "The Chapter Ends" IN Anderson, Starship (New York, 1982), pp. 253-281 AT p. 258.

In The Seedling Stars by James Blish, "Adapted Men" colonize thousands of extrasolar planets, thus enormously increasing the possibility that human beings will become masters of the galaxy. At the same time, a basic continuity of form is maintained because total bodily transformation would mean total mental transformation. A man given the form of a cockroach would think like a cockroach. He would be "Adapted" but not a "Man." Jovoid planets are left to other races, reminding us of the Hulduvians in "The Chapter Ends" and the Ymirites in Anderson's Technic History.

In "Watershed," the culminating story of Blish's pantropy future history, a spaceship from a civilized part of the galaxy visits the ancient Earth which has changed so much that it is no longer habitable by the original human form. In "The Chapter Ends," presented as the culmination of Anderson's Psychotechnic History, Galactic psychotechnicians evacuate the peasant population from Earth so that the Hulduvians will have unlimited access to the cosmic forces at the galactic periphery. Thus, there are some parallels between these two stories.

There are problems with regarding "The Chapter Ends" as an instalment of the Psychotechnic History. See Chronological Questions and Fifty Thousand Years. However, I like the idea that the Nomads provided continuity, including some knowledge of psychotechnics, through the Third Dark Ages which could have included interstellar empires.