Regarding the 1963 novel Planet of the Apes by Pierre Boulle and the 1968 film adaptation with the same name and loosely based on the book, how do the aesthetic sensibilities required by the film differ from those required by the original source (the novel)? Is the difference important?

Planet of the Apes (French: La Planète des singes) is a 1963 science fiction novel written by French novelist Pierre Boulle. Because of its success in France, the novel was published in English the same year, in the United States, under the all familiar title Planet of the Apes; and in England, in 1964, under the title Monkey Planet.
The novel received several adaptations: a media franchise of nine films, two TV shows (one animated), and several comic books; all of which received mixed-to-positive reviews, especially the 1968 homonymous film adaptation of the novel, directed by American film director Franklin J. Schaffner, and written and adapted by American screenwriters Michael Wilson and Rod Serling. The film received tremendous commercial success and even critical acclaim, with critics branding it a classic and calling it the best science fiction film produced in the 60’s and 70’s.
Both the novel and the film follow the story of a group of human explorers and astronauts who crash land their spaceship on a planet in which intelligent, technologically advanced, and human-like apes are the dominant species of the society, and the humans are the ones who are considered savages and uncivilized animal-like beings, and are treated as pets and slaves. Interestingly enough, the plot and the general apocalyptic aesthetic are probably the only two things that are similar between the novel and the film.
For instance, in the novel, the planet on which the space traveling group (Ulysse Mérou, Professor Antelle and Arthur Levain) lands is called Soror; in the film, the three astronauts (Taylor, Landon, and Dodge) crash land their spaceship by sinking it into the sea on an unknown planet, which is later revealed to be Earth. There is an interesting scene in which the main protagonist—Taylor (played by Charlton Heston) discovers that the Statue of Liberty has been blown up and is buried in the sand.
Unlike Boulle, who made his protagonists human explorers who visit other planets in order to find new species and/or colonize the newly-discovered worlds, Schaffner wanted to portray his vision of a futuristic, post-apocalyptic society which might have been a result of a fatal nuclear or environmental war. Essentially, this pivotal moment is what differentiates Boulle 1963 sci-fi satire from Schaffner’s personal analysis on humanity’s greed, arrogance, and its inclination to self-destruct.
Another obvious difference is the language barrier. In the novel, Ulysse does not speak the Simian language, and therefore must learn it in order to communicate; the film, however, omits this whole language-learning process, and the apes speak English. The apes also have a religion based on the "Simian Sacred Scrolls," while in the novel they are a non-religious species. There are also several minor characters from the novel that have been cut or transformed in the film. For instance, instead of Sirius—Ulysse’s son—in the film we have Lucius, Zira’s nephew. All of these changes have been made to preserve the stability, consistency, accessibility, and simplicity of the plot.
The most notable difference, however, is the ending. In the novel, the group manages to escape Soror, only to discover upon landing that there are now civilized monkeys on Earth as well. In the film, the fate of Earth and humankind is already doomed as a result of humanity’s vanity, which is, essentially, the main characteristic that separates us from other animals.
In conclusion, Planet of the Apes, in both written and visual media, presents an extremely appealing, thought-provoking, and counter-cultural concept. What makes the difference between the novel and the film important, is the fact that it raises numerous sociological and biological questions, making the audience wonder what separates an animal from a conscious, intelligent, and reasonable being; what divides a species, or a race for that matter; what is the limit of humanity’s sense of superiority; and are all humans really entitled to be the “good ones,” if they are personally responsible for their own downfall.