The Songs of Distant Earth is a 1986 science fiction novel by Arthur C. Clarke.
In the 3800s a faraway oceanic planet of Thalassa has a small human population sent there by embryonic seed pods to continue the human race before the Earth was destroyed. Thalassans are quiet, stable, and free from religion, supernatural influence, monogamy and sexual possessiveness. This is all disrupted with the arrival of the Magellan, an interstellar spaceship from Earth containing one million colonists who have been put into cryonic suspension. The arrival of the visitors from Earth is a monumental event for the easygoing Thalassans, who never expected to see or hear from any other human beings.
The visitors explain that scientists in the 1960s discover that the neutrino emissions from the Sun will cause it to become nova around the year AD 3600. So humanity had to develop advanced technologies to send out seeding ships containing human and other mammalian embryos and stored DNA sequences, along with robot parents, to habitable planets. One such ship was sent to Thalassa and successfully established a human colony in the year 3109. A quantum drive (propelled by ZPE) allowed a fleet of manned interstellar vehicles, including the Magellan which escaped the Earth three years before the Sun exploded, taking off from a space elevator.
The rest of the story is about the relationship between the visitors and the Thalassans, and sea scorpions in the Thalassan oceans that may have the potential for developing into a future intelligent species.