The novel “The Seedling Stars” by James Blish was published for the first time in 1955. It’s the fix-up of previously published stories.
Donald Sweeney is an Adapted Man, born with physiological modifications that allow him to survive in environmental conditions that would kill a normal human being very quickly. He’s a product of pantropy, a controversial experiment that aims to adapt humans to environmental conditions they might find on other planets in order to colonize them.
A group of Adapted Men took refuge on Ganymede thanks to adaptations that allow the members of the group to be comfortable in the conditions existing on Jupiter’s moon. Sweeney is sent to Ganymede by the Earth authorities with the aim of infiltrating the group of fugitives to help get them back to Earth, especially their main scientist. In return, he was promised to be modified to be able to live in the Earth’s conditions.
In 1942 James Blish published the short story “Sunken Universe” in which he hypothesized a type of planetary colonization different from those typical of science fiction. Even today, in this type of story, when humans want to colonize a planet that’s not suitable for human life, they terraform it or build artificial habitats. Instead, Blish introduced the idea to modify humans so that they could live in the conditions of the place to colonize. In 1952, he revised the story to the point of publishing it under the new title “Surface Tension”. The success prompted the author to write three more stories on the same subject, and in 1957 they were fixed-up and published as if they were a novel.
James Blish had a degree in microbiology, and in the stories that form “The Seedling Stars” he includes descriptions of the physiological changes made to the Adapted Men to make them compatible with the environments to be colonized. However, in the 1950s at least some ideas were already challenging scientific plausibility, starting with the first story, in which settlers are adapted to a marine environment among other things by making them microscopic. It seems unlikely to say the least that we can reduce the size of a human being to that level while maintaining the complexity of his body and especially his brain.
Plausibility issues aside, I think “The Seedling Stars” works because the pseudo-scientific element ends up being secondary in stories that go beyond the adventure. James Blish could create interesting characters, even in the short fiction, and that’s true also for the Adapted Men, whose physical characteristics not only make them suitable for certain environments but also lead them to appreciate them whereas normal humans could find them desolate or hellish.
In “Seeding Program”, James Blish recounts the first applications of pantropy with the controversies surrounding it and the fears of some human beings that their descendants are monsters. In the other stories, the settings are different and also the consequences of the colonization of those places. The people who run the colonization missions left messages to the Adapted Men, but it may happen that they’re interpreted religiously and anyone who questions that interpretation is treated as a heretic. In the first story published, the Adapted Men try to develop science and technology in a marine environment with all the ensuing problems. Thousands of years in the future, humanity will be largely made of Adapted Men, a situation that some “natural” humans may struggle to accept.
“The Seedling Stars” suffers a little for the fragmentation in various stories with different characters, even if the different environments enrich it. Today, James Blish could write a series of novels on the subject rather than some short fiction. There’s the remarkable sense-of-wonder given by an idea also well developed within the limits of short fiction, and for this reason, I think it’s still a must-read work.