Written By: François-Noël Vanasse
Escape from the Planet of the Apes (1971)
“Good evening. This is Bill Bonds reporting from Los Angeles… where the biggest story since the moon landing broke this morning when two apes talked.”
In 1973, a helicopter rushes out over the ocean towards a downed U.S. spacecraft. The craft is attached to a tow line and reeled to the shore where military men and generals are eagerly awaiting it. The door is opened and the three astronauts who emerge are proudly welcomed and saluted. To the astonishment of everyone, the three astronauts are apes. Cornelius and Zira are joined by Dr. Milo (Sal Mineo). What follows is a montage of the world reacting to the news which settles on a meeting in the Oval Office where the President of the United States (William Windom) authorizes a presidential investigatory commission and sends his scientific advisor Dr. Otto Hasslein (Eric Braeden) to assist the commission.
Escape introduces quite a lot of new information to the franchise and the timeline. This sort of thing is often called a “retroactive continuity” or “retcon” which occurs when new information contradicts and overwrites previous facts in a serialized work of collaborative fiction like television, video games, or graphic novels. In the previous films, Taylor and Brent both mentioned the theories of a scientist named Hasslein when discussing the principles of time dilation. When approaching the speed of light, time would pass normally from the point of view of the traveler, but as a result of the traveler’s incredible speed, time would actually be passing more slowly for the traveler compared to people moving at normal speeds. This is a simple extension of Einstein’s theories on relativity thus making Hasslein a stand-in for the famous physicist. In Escape, however, he becomes the primary antagonist, very close to the character of Dr. Zaius in the novel, all the while being an authority on the physics of time.
In order to account for the three apes being able to travel back in time, a disturbance in time is created, attributed vaguely to the energy released in the destruction of Earth in the 40th Century, which is similar to the “Hasslein Curve” that Brent maintained he must have passed through on his way to the Planet of the Apes. The ship carrying the escapees is revealed to have been Taylor’s ship salvaged and refurbished by Dr. Milo. Zira and Cornelius are now married and Zira eventually reveals that she’s pregnant. Furthermore, Cornelius claims to have had access to secret archaeological data hidden from the public, which, in accordance with what is written in The Sacred Scrolls, tells the complete story of how the civilization of men was replaced with the civilization of intelligent apes.
Escape is a bit of a return to form for the series which nicely inverts Boulle’s original story while retaining most of its themes and commentary. For example, in the novel, Dr. Zaius conducts a breeding experiment with Ulysse and Nova but becomes terrified that their son, who is just as intelligent as his father, will one day beget a race of men capable of overthrowing the apes. Hasslein fears the same but with the roles of ape and man reversed. There are also several discussions on the ethics of medical research conducted on animals with most characters taking the surprisingly enlightened stance that we can hardly expect the apes of the future to treat their humans any better than we treat other animals today. Of course, the implicit fear of anyone looking at losing power and privilege is that the tables will be turned on them. It’s why anti-feminist attacks accuse women of hating men or of seeking to install dystopian societies where men will be treated unfairly. The same line of thought occurs with baseless fears about white slavery and racism against white people as a result of demographic shifts and successful Civil Rights movements.
The story of Escape acts on a smaller scale than its predecessors. There are only a handful of apes and the majority of the scenes take place in and around Los Angeles. The three ape-tronauts are taken to the zoo where their 20th Century counterparts Dr. Lewis Dixon (Bradford Dillman) and Dr. Stephanie Branton (Natalie Trundy) perform simple exercises to test their memorization and problem-solving skills. The apes are kept in holding cages in the zoo’s infirmary and share a wall of their cage with one containing a gorilla, much to their disgust. Zira cannot help herself and ends up revealing their ability to speak and reason to the humans after acing the tests. While the humans are collecting themselves in the next room, taken aback by the revelation, the gorilla in the adjacent cage reaches through the bars and crushes Dr. Milo, killing him. After briefly mourning offscreen the apes are presented at the public investigation hearing where they answer direct questions. Zira and Cornelius win over the crowd and become overnight sensations. What follows is a great deal of easy fun. The apes are moved to an upscale hotel, they obtain fashionable human clothes, and they are chauffeured around L.A. Zira gets to flex some feminist muscles at a local women’s association and Cornelius is suitably unimpressed by a prize-fight. If it weren’t for Hasslein scurrying around in the background it would all be harmless good fun.
Hasslein gets Zira drunk and questions her some more about the future. Fortunately, this is from a time before the negative link between pregnancy and alcohol had been established or he would really be a villain. He is able to convince the President to have the apes sequestered and interrogated at Area IX, a nearby military base. While the commission overlooks Zira’s dissections, vivisections, and experiments on human animals, and excuses Cornelius from any responsibility for merely being aware of history, they end up agreeing with Hasslein that their unborn child poses a threat. While there are many stories which involve children prophesied to bring about change who are feared by the powers that be, the Biblical story of Jesus is explicitly mentioned. The President specifically compares Hasslein to Herod, the King who supposedly ordered the deaths of all male infants around Bethlehem to prevent the rise of another “king of the Jews”. The movie tries to hide it a little behind the science fiction with discussions about the ethics of killing an infant Adolf Hitler or even Hitler’s remote ancestors, but the child is eventually born in Armando’s Circus (which acts as a substitute for the biblical stable) after Zira and Cornelius successfully escape from Area IX and evade the patrols with help from Drs. Dixon and Branton. A camel is even led through in the background while Armando is harboring the ape family.
The hunt to find the ape takes up the second half of the movie and features a lot of charged imagery of jeeps and trucks rushing in and out of military bases and police and soldiers running through urban environments with their rifles drawn. In the early 1970s, it’s pretty easy to see where these images would have come from. In the rest of the film the allegory doesn’t get spread too thin and there are interesting moments where it defies expectations from the previous films. For example, the religious themes that Beneath doubled down on are sidestepped in Escape. When a priest on the presidential commission stands up in pearl-clutching bewilderment when Cornelius explains that he and Zira are lawfully wedded the priest is summarily ordered to sit back down and not a peep is heard from him again. Similarly, the general public is enamoured with Cornelius and Zira as opposed to the fear and confusion with which Bright Eyes is treated. Women and children fled from Charlton Heston’s Taylor, Julius even calls him a “freak”. No such epithets are hurled at the escapees except “Monkey” which is a slur according to Cornelius and used only by the ignorant and bigoted agents working with Hasslein at Area IX.
Armando is an interesting character. He is a religious man who seems to ardently believe in fate or destiny and exists in opposition to Dr. Hasslein. Armando is also a passionate businessman trying to preserve the dying live-animal travelling circus. Armando knows, and is grateful to, Drs Dixon and Branton through previous veterinary consultations. There is no shortage of ruthless, mean-spirited circus owners in fiction, but Armando is presented as a compassionate and thoughtful man. Hasslein says he struggled with whether or not what he’s doing is right but ultimately succumbs to his ego, perhaps a superiority complex, and goes so far as to directly defy the President’s orders to capture the apes alive. He takes it upon himself to gun down Cornelius and Zira, and shoots the swaddled baby chimp after a wounded Zira drops it. Armando on the other hand is firmly against fighting destiny, considering it God’s will, and apparently gladly welcomes our future ape overlords. He even gives Cornelius and Zira’s child, whom they name Milo, a medal of St. Francis of Assisi (patron saint of animals) to protect him.
The finale is a tense chase and gunfight set on an abandoned oil tanker where Zira, the baby, and Cornelius have been sent to hide out for a week until they can be smuggled away inside Armando’s circus. The movie ends with Hasslein brutally murdering Zira and the baby only to be gunned down by Cornelius who is then killed by the police on shore. The twist is that Zira and a mother chimp in Armando’s circus switched newborns. Zira throws the corpse overboard to hide this fact and crawls over to Cornelius to die by his side. The film ends with baby Milo in a circus cage, medal around his neck, crying “Mama!”
Where Planet of the Apes takes place in a society without separation of Church and State, Escape takes place in our world. The way Dr. Hasslein decides to act unilaterally to protect humans, the way his influence corrupts the others around him, becomes in hindsight eerily prescient and would easily fit into the canon of movies made in the fallout of the Watergate scandal.
Conquest of the Planet of the Apes (1972)
“Because your kind were once our ancestors. Because man was born of apes, and there’s still an ape curled up inside of every man. You’re the beast in us that we have to whip into submission. You’re the savage that we need to shackle in chains. You taint us, Caesar. You poison our guts. When we hate you, we’re hating the dark side of ourselves.”
When Cornelius was brought before the commission in Escape, his testimony included an account of how the world of man fell and the planet of the apes began. According to him, a great plague was going to wipe out domestic cats and dogs at which point they would be replaced by apes. Eventually, the apes were going to become slaves able to do chores such as manual labor, cleaning, and shopping. One day, hundreds of years in the future, an ape named Aldo would become capable of speech, uttering the fateful word “No!” after which he would lead an ape rebellion to freedom. The events described by Cornelius take place in Conquest but, presumably as a result of changes to the timeline created by his traveling back in time with Zira and Dr. Milo, they do not take place over a 500-year period and instead star his son who has been renamed Caesar (Roddy McDowall).
In the year 1991, apes are shuffled through a North American city by armed guards where they are trained by black-uniformed members of Ape Management and Ape Control to shine shoes, set tables, carry parcels, sweep streets, and mop floors. Chimps in green, gorillas in red, and orangutans in yellow jumpsuits. Armando and Caesar arrive in the city via helicopter and it is apparently Caesar’s first time among humans who do not know his secret because Armando is very concerned that others will discover it and then do to Caesar what they did to his parents. Upon their arrival at street level, an illegal gathering of apes is broken up by armed guards who are dressed very much like SS agents.
As Caesar and Armando walk around the city handing out circus fliers we learn that cigarettes are no longer lethal, that ape waiters are tipped in raisins, and that human laborers protest the hiring of ape replacements. We also learn that apes aren’t exactly great at their job. An orangutan in a bookstore collects the wrong book from the shelf, a chimp hairdresser messes up, and a chimp waiter flees from the flambé because he has not been properly conditioned to fire. Caesar also mutually catches the eye of a female chimp named Lisa (Natalie Trundy) as they continuously run into one another throughout the trip. The two new tourists also pass in front of a small monument to deceased pets which were wiped out in 1983 from a virus brought to Earth by astronauts after which they were replaced by increasingly large and intelligent monkeys due to human desperation for pets.
When an ape in chains is spooked by protesters, he is brutally beaten by guards. The violence is stopped by Macdonald (Hari Rhodes), one of the governor’s aides, who is accused of being an ape lover which the other guards seem to believe jibes with his blackness. Governor Breck (Don Murray) is shown to be a brutal man who fears and hates the apes. It’s a full-on science fiction future. North America is a police state apparently divided between “cities” and “provinces” and depends upon ape slavery to function. Unable to control himself, Caesar blurts out “Lousy Human Bastards!” which upsets the guards. Armando takes the blame in order to protect his adopted son and decides to turn himself in. Thus forced to go their separate ways, the pair will never meet again.
Caesar follows Armando’s final orders and sneaks into a shipment of foreign apes destined for slave training. He is clothed, fingerprinted, and escorted through the facility. It’s a madhouse where apes are beaten and tortured so they can be taught to carry serving trays, or conditioned to fire using flamethrowers and bananas. They are strapped to their backs and tortured with some sort of electrical headset while a speaker booms “No!”. Caesar is given a banana and put in a cell with three unfed chimps whom he immediately and quietly brings under his control, and distributes the banana. Armando, meanwhile, deals with very suspicious interrogators and denies any connections to the talking apes Cornelius and Zira.
Caesar and the other conditioned apes are taken through the training seen in the film’s opening where they are taught to wash their hands, pour drinks, and make beds. Afterwards, Caesar is one of the “superior males” selected to inseminate a receptive female, which happens to be Lisa, to which he apparently has some difficulty objecting and appears to resign himself. Caesar is sold at auction to Governor Breck for $1,500 where he is described as being a male in his prime. He overhears conversations about Breck’s distrust and hatred of apes while being taken through his paces by Macdonald and is ordered to do menial tasks to prepare him for life in service to the Governor’s office. Caesar feigns ignorance and stupidity to protect his identity by making a small mess instead of successfully mixing the governor’s scotch and soda. Caesar is allowed to choose his name at random from a book on the Governor’s shelf and flips through it until he finds “Caesar”. While no one is furious at Caesar for failing at mixology, they do deem him unsuited for working as Breck’s personal office slave and they transfer the ape down to the Control Detail instead. The Control room is the underground nerve center of the city where Blinking Light Units flash in the background and electronic doors whoosh open and shut.
Coincidentally, Caesar finds Lisa working at the Control Detail. Here information is gathered from all over the city and broadcasts are made to the citizens. It’s also here that Caesar overhears the news of Armando’s death. After he was forced to undergo a torturous lie-detection procedure called The Authenticator, Armando fought with the guards and fell out of a window. Taking the news understandably poorly, Caesar gets some air, tears streaming down his face, and rubs his finger along Armando’s name on one of the circus fliers hanging in a store window. Caesar’s anger turns to rage at the loss of his surrogate father and he runs through the city bellowing with it.
The montage that follows shows that Caesar has apparently been quite successful in organizing an ape rebellion. Small shows of resistance have been occurring with increasing frequency and his ape followers are shown gathering supplies, including weapons, and delivering them to their underground lair. Unfortunately for his nascent rebellion, the computers at Ape Management finally track Caesar down and the Governor’s men capture him. Caesar is tortured into screaming “Have pity!” and is sentenced to death by electrocution from the torture machine. Macdonald, despite having argued with Caesar over his plans for violent revolution, helps the ape revolutionary to fake his own death and escape.
Caesar immediately leads the apes from their hideout to Ape Management where they strangle the guards with their chains, beat them with their own clubs, and light the flame thrower operator on fire. Caesar even uses the power of speech to send out false commands urging the guards against using lethal force. In response, the governor confines the citizens to their homes and deploys troops. If Escape used imagery of soldiers and police to recall the riots of the late 60s, Conquest confronts audiences directly with the pictures and images of those riots. As Caesar’s apes confront squadrons of armed riot guards they display mastery of fire and successfully make their way to the Control communications bunker and cut through the door with a torch.
Outside the bodies of the soldiers are piled up, bloodied and crumpled, while the apes chant and dance, beating the dead bodies. Breck is chained up and tossed into the center. Macdonald pleads with Caesar, stating that violence will only beget more violence, but Caesar forcefully disagrees and delivers his speech ushering in the inevitable domination and reign of the apes. At this point the two final cuts diverge. In the original ending, the apes beat Breck to death and the city burns. In the edited theatrical cut Lisa stammers out, “No” and Caesar delivers a second speech about being compassionate and humane, sparing Breck.
The balance between violent revenge and merciful peace inherent to the ending of the movie is revisited in the immediate sequel and would become the primary theme of the reboot trilogy centering around another ape revolutionary named Caesar who struggles with the same ideals. Conquest is about fascism, the inevitability of violent revolution, and the ultimate fruitlessness of violence to achieve lasting positive change and so is the final chapter in the original Planet of the Apes series.
Battle for the Planet of the Apes (1973)
“Ah, if only my mother and father, whom I was too young to remember… If only they’d lived, perhaps they would have taught me if it was right to kill evil so that good shall prevail.”
This film is book-ended by a lecture being given by The Lawgiver (John Huston) as he seemingly recites from one of his sacred scrolls. After Caesar’s rebellion, a nuclear war took place between the powers that be and, in the ensuing chaos, Caesar was able to lead the apes and several human followers out of the city, across the wasteland, and successfully founded an Ape City. The story takes place some thirty years later and follows the events that led to the breaking of the simian society’s most sacred law ,“Ape shall never kill ape.”
Ape City is green and bucolic. The apes are all wearing their final costumes from the original film with chimps in green, orangutans in orange, and gorillas in purple. All of the apes can speak now and they live side by side with humans who are mostly seen doing manual labor and wearing very dirty brown outfits. The exceptions are Teacher (Noah Keen), who gives reading and writing classes to the apes, and Macdonald (Austin Stoker) who is the brother of Hari Rhodes’ character from Conquest and acts as some sort of aide or advisor to Caesar. They both have crisp, clean outfits. Everything in Ape City seems pretty idyllic. Caesar has a son with his wife, Lisa, named Cornelius (Bobby Porter). The apes have science and mathematics thanks to the polyvalent orangutan thinker Virgil (Paul Williams). The whole of society is vegetarian by decree of Caesar and survives on fruits and nuts. Violent, evil, things are brewing, however, in the heart of gorilla General Aldo (Claude Akins).
Aldo is a fool. He has very little brains and is humiliated by it whenever he does attend class. His repertoire for social interaction is confrontational and foul tempered. His only motivations are personal glory which he aims to achieve by wiping out all humans and seizing power for himself by smashing Caesar. One of the few things Aldo seems to enjoy is riding horses and he barrels through crowds nearly every time he takes it up. It’s a little hard to believe this creature could ever be appointed general in a society run by someone such as Caesar.
Battle seeks to combine a more hopeful version of the morality play that has consumed the series with the task of crafting and marrying the history of the two timelines. The apes live in a city across a wasteland from The Forbidden City which is burnt, melted, and twisted much like New York City was in the heart of The Forbidden Zone as featured in Beneath (1970). The humans living underground within the city suffer from blemishes as a result of radiation sickness and wear very silly caps reminiscent of the hoods worn by their psychic descendants in the latter film. They also possess an alpha omega nuclear missile. These humans are led by another madman named Governor Kolp (Stephen Darden). Although Kolp protects and maintains the nuclear bomb, he is defined primarily by a deep hatred of the apes. Kolp is the human mirror of Aldo, and he is similarly bored by peace, craving instead violence, war, and the potential for glory. Kolp rules disinterestedly and the apes intruding on the ruins of the city is the most interesting that has happened to him in a while. Kolp pushes for war despite the misgivings of his loyal followers .
The attack itself is supposedly in retaliation for Caesar, Virgil, and Macdonald sneaking into the old city archives in search of recordings from the Presidential Commission featured in Escape. Friction remains between the apes and the humans living together. The two communities work together but live under ape law. Teacher is admonished for saying “No” because it is illegal now for humans to say this word to apes as a result of the torturous conditioning the apes underwent. Having to juggle the interests of apes and humans weighed strangely on Caesar; Macdonald, a supporter of Caesar but also a firm believer in human equality, suggested that the recorded revelation from his parents might help Caesar decide to change the current path of ape dominance. Caesar was especially taken with the idea of seeing and hearing his parents for perhaps the first time and agreed to the mission. The group succeeded in listening to the tapes, with Caesar proclaiming that he knows what he wants to change, but barely managed to escape from Kolp’s men who chase them through the underground tunnels.
Upon returning from the forbidden city, an Ape Council is summoned in which Caesar declares his intention to begin preparing for war with the mutant humans. To Aldo’s outrage a handful of humans have been invited to the Council as fellow counselors. The meeting is spied upon by some of Kolp’s scouts who report back that Caesar held a war council. The gulf of misunderstanding between the two tribes is widening and war seems increasingly inevitable. In a secret meeting with the other gorillas, Aldo declared his intentions to raid the armory and overthrow Caesar. The whole thing is overheard, as Aldo repeats himself often, by Cornelius who is out looking for his pet squirrel. Cornelius is chased up a tree by Aldo and his branch is chopped down by Aldo’s sword. The fall fatally wounds Cornelius who succumbs to his injuries a few days later.
Caesar becomes unable to leave his slowly dying son’s bedside while outside Aldo declares Martial Law, locks up humans in the corral, breaks into the armory, and confines the apes to their homes. Eventually, Virgil sneaks into Caesar’s hut and reveals what Aldo has been doing shortly before Cornelius dies. A combination of Virgil, Macdonald, and Cornelius’ testimony is able to show that Aldo murdered Caesar’s son, but not before the titular Battle takes place.
Near the closing of the film, one of the Governor’s assistants, Mendez (Paul Stephens) who has pleaded with the Governor to leave the apes alone in peace throughout the film begs Kolp’s other aides to disregard the Governor’s orders to launch the missile. Rather than launching it, Mendez wishes for respect, veneration, and worship of the bomb. Mendez and his descendants and successors would presumably go on to found the religion of the mutants from Beneath living under the ruins of irradiated cities. Before launching the attack on Ape City, he leaves behind orders to launch the missile, thus destroying the planet, should he fail.
The humans arrive in Ape City in jeeps and a school bus where they firebomb the barricade and blow up the tree-houses. The apes are eventually forced to retreat and the human trucks drive through the burning barricade. Kolp walks through the city, apparently about to fulfill his own orders to leave behind nothing but rubble when he comes across a wounded Caesar. Holding Caesar at gunpoint, Kolp prattles on, but is distracted by a grieving Lisa after which most of the dead apes spring to life and ambush the humans. The retreat to the city was a ruse to trap Kolp’s soldiers and take them prisoner. Kolp and a few men make it back to the bus, but Caesar lets them go displaying similar magnanimity as in the edited ending of Conquest.
Aldo’s gorilla cavalry finally shows up again and attacks the bus, killing Kolp and the last of his army. Aldo basks in the praise and chanting from his soldiers. Upon returning to the city, however, Aldo’s attempts to prevent Caesar from freeing the corralled humans are thwarted by the public revelation that Aldo has broken their most sacred law by killing Cornelius. Aldo is chased up a tree by Caesar and plummets to his death. The freed humans then plead with Caesar for equal rights under ape law and Caesar finally relents when he is reminded by Virgil that Aldo has demonstrated that violence, betrayal, and murder are not only the province of humans.
The twist ending to Battle is that, 600 years later in the year 2670, Lawgiver has been teaching to a class made up of ape and human children. This is in stark contrast to the writings of The Sacred Scrolls in the original timeline and suggests a newer and better future for the planet than its violent destruction in year “3950 something”. The happy ending is left open to interpretation, however, as the camera settles upon a statue of Caesar which, upon close-up of his face, sheds a single tear.
For the better half of a decade, Roddy McDowall played an intelligent chimpanzee from the future. Playing off Kim Hunter’s Zira he was forced to invent all kinds of facial expressions and body language that could play through the thick prosthetic makeup. As Caesar, the son of his character Cornelius, McDowall carried an entire film as the only speaking ape. In the final film, a limited budget and a lack of experience showed, as Caesar is just about the only believable ape of the bunch. McDowall would also go on to portray Galen in the spin-off television series. It’s been half-joked that this series is some of McDowall’s best work and that it’s the role he was born to play. In many respects, the series owed much of its success to the will and skill of its performers.
Producer Arthur P. Jacobs’ five original Planet of the Apes films brought science fiction to the big screen on the backs of the incredible performances by its ape actors. It popularized the genre by showcasing its ability to explore contemporary social and political themes. The series discussed civil rights through the topsy-turvy world of the apes, the devastation and finality of nuclear war through the wasteland of The Forbidden Zone and the apocalyptic worship of the mutants. It further covered religious themes with Dr. Zaius, The Sacred Scrolls, and the relationship between science and dogma. Characters frequently try to understand the will of God and act to fulfill it. The zealotry and trumped-up holiness of the series’ villains showcase the corrupting influence of power, and the thirst for power, in characters like Zaius, Ursus, Hasslein, Breck, Aldo, and Kolp. In this way, the whole series acts as a clever allegory for the self-supporting nature of the status quo.
When you’re on top, the status quo seems fine and the more dependent you are on things staying the way they are, the more resistant to progressive change you become. When you’re on the bottom, however, as Taylor and the other astronauts found themselves, the whole world suddenly seems like an upside-down madhouse. No one in the audience could possible support the captivity, experimental brain surgery, forced breeding, and castration that Taylor is threatened with and yet the apes in charge do so easily. The series made these themes explicit when Caesar is thrust into ape slavery. It is difficult not to sympathize with his plight and his ultimate call for violent revolution. Thus the series’ most important theme is the senseless, reciprocal, and cyclical nature of violence. The slave-master fears their freedom because his ultimate fear is that he will be treated as poorly as he once treated his slaves. There are few ways out of this cycle of violence but one of them seems to be great men and women who struggle for peace and lead non-violent revolutions to victory. Planet of the Apes gave us a leader in Caesar who managed to install at least 600 years of peace in his community of apes and humans living together even though the timeline’s ultimate fate remains purposefully ambiguous.
APPENDIX (PART TWO):
**WARNING: SCIENCE CONTENT**
Beneath The Planet of the Apes seems intended to have ended the series since it features the destruction of planet Earth. To dig the series out of this obvious corner the rest of the films take place in the past, closer to our present. Confronted by the authorities Cornelius and Zira explain that Dr. Milo, an apparently unparalleled mechanical genius, successfully refurbished Taylor’s spacecraft (which has been humorously nicknamed Icarus by fans) and that the three apes escaped together just in time. They even describe watching the Earth crack in two.
Setting aside the absurdity of someone with the film-version apes’ apparent pre-industrial understanding of physics and engineering putting a spacecraft back in working order, let alone piloting it, the Earth cracking in two is a bit of problem. The real-world but theoretical cobalt bomb doomsday weapon is not designed to be a dramatically more powerful explosive device than traditional thermonuclear weapons. The goal is instead to produce and spread excessive amounts of radioactive isotopes of cobalt (Co-60) and thus increase the levels of deadly fallout radiation.
The final three films in the original series also provide us with a time-travel tale and all of its associated paradoxes. While the first film featured present-day humans traveling to the distant future, it was intended to be the theoretically plausible kind of time-travel where humans approaching or exceeding the speed of light experience relative slower time than humans traveling at traditional speeds. Escape has to invent an explanation whole cloth for how the apes could have traveled back in time resulting in some silliness about the destructive energy released by the bomb creating a rupture in space-time that is meant to account for how Taylor and Brent became stranded in the future as well.
Regardless of how it happened the effects time travel itself are fraught with possibilities. Dr. Hasslein describes time as a freeway with infinite lanes and suggests that it might be possible to change lanes and therefore change one’s future. It is unclear, however, whether the future has been changed in the series or whether it is self-fulfilling. In the original timeline (Films 1 & 2) the apes took over the world and humans became wild and mute. No explanation is given for how this occurred except scripture from The Sacred Scrolls which, according to Zaius, blames humans for killing themselves and wrecking the land which is corroborated by the matte-painting devastation of ruined NYC. Film 3 provides a fuller explanation courtesy of Cornelius’ testimony which mostly mirrors the description from Boulle’s original novel. The question becomes, however, if and how Cornelius and Zira traveling into the past will affect the future events we have already witnessed.
Because Film 4 doesn’t concord exactly with Cornelius’ account it’s possible then that the past has been changed. Instead of Aldo hundreds of years in the future leading to apes to freedom it was Caesar decades in the future. However the series has a habit of changing little details and forgetting things in between films. These were the days before home video and online databases. It was difficult to be a nerd with an encyclopedic knowledge of your favorite properties. Fans obsessed with continuity had not yet grown up to become artists obsessed with continuity. Debate nowadays rages as to whether or not Caesar’s birth in the 20th Century changed the future (perhaps creating a second and parallel timeline), or is what always resulted in the Planet of the Apes continuity in a kind of circular, cyclical, paradox. Film 5 ends with humans and apes living in harmony but leaves the door open for sectarian tensions. The graphic novels based on these films have gone through great lengths to bridge the gaps between Battle and Planet but these, along with the cartoon and live-action television show, can safely be considered non-canon.