In the 2009 Star Trek movie from J.J.Abrams, we are introduced to an entirely new timeline which has officially been named the “Kelvin Timeline.” This timeline splits in the year 2233 when a Romulan mining vessel, the Narada, appears out of a singularity leading to the destruction of the USS Kelvin and the death of Captain George Kirk, James T. Kirk’s father. We later learn that this singularity was created in 2387 by Ambassador Spock in an attempt to absorb the energy of a supernova that was going to destroy Romulus. Unfortunately, Romulus was destroyed leading to the captain of the Narada, a Romulan named Nero, forging a vendetta against Ambassador Spock for not saving his home. The timeline at this point splits off from the Prime Timeline (encompassing all previous Star Trek TV shows, movies, the works) and continues on this path as far as we can see.
Something interesting is that although the timeline was wildly altered, a lot of the same large events still happen. For example, Kirk still becomes captain of the Enterprise, Spock and him become friends, and Scotty becomes a member of the crew. So is that because they are fixed points in any timeline? They are so close to the anomaly it should drastically change it, right? Well, Data has an answer for us. In the TNG episode “Parallels,” Data explains quantum physics by saying that “all possibilities that can happen do happen” when dealing with a parallel universe. Essentially, there are certain events in a timeline that are more probable than others, so it is likely that even with changes to the timeline, a lot of the same events may take place.
Due to the death of his father on 2233, Kirk grows up a little differently than he did in the Prime Timeline. In the original series, the anomaly does not occur and Kirk’s father grows old enough to see him become Captain of the USS Enterprise. However, in the new movie Kirk’s father dies and so Kirk is raised by his mother and a stepfather and we see him as a young boy wrecking up the place and very noticeably has a problem with authority. He then grows up a little to get into a bar fight and is recognized by Captain Christopher Pike who convinces Kirk to join the Academy to prove him wrong. Both end with Kirk going to the academy, but for different reasons and under different circumstances.
During command training in both timelines, Kirk confronted the Kobayashi Maru scenario, a simulation used to evaluate a student's reactions to a "no-win" battle and rescue situation. Kirk refused to accept his first two defeats. So before making a third attempt, he secretly reprogrammed the simulation computer, consequently becoming the only cadet in Academy history to beat the "no-win" scenario. In the Prime Timeline, Kirk ends up earning a commendation for original thinking. Whereas, in the Kelvin Timeline, Kirk was nearly tossed out of the Academy for his rule breaking and placed on suspension. The same event occurred, but with different outcomes because of it.
The theory is also supported in “Star Trek: Into Darkness” where they reenacted the scene from “Star Trek II: The Wrath of Khan” where Spock sacrifices himself to save the ship and everyone in it, only to die in one of the most heart-wrenching scenes literally ever. However, in “Star Trek: Into Darkness” it is Kirk who sacrifices himself to save the ship and everyone in it. This is a great example that certain events are more likely to occur despite the changed timeline. Spock "dies" in the Prime Timeline, not Kirk. The changes in the timeline allowed them to be on opposite sides of the glass, but time stated that the event would occur regardless.
There is one other major “timeline altering” anomaly which occurs 25 years after Nero arrived in 2233. He had been waiting for the arrival of Ambassador Spock, of whom he blamed the destruction of Romulus, so that he can capture him and maroon him on Delta Vega, a nearby planet, and watch helplessly as his own homeworld of Vulcan was destroyed at the hands of Nero as an act of vengeance. This destruction of the planet Vulcan set the events of "Star Trek: Into Darkness" in motion, diverging even more from the Prime Timeline. As a result of the destruction of Vulcan in 2258, Starfleet Admiral Alexander Marcus, head of Section 31, starts on his quest to seek out new and innovative ways to militarize and defend the federation. And, although the destruction of Vulcan was not at the hands of the Klingons, he felt that they were the greatest threat and a war was inevitable. Section 31 discovered the SS Botany Bay, a ship full of cryogenically frozen supermen, and awoke the infamous Khan Noonien Singh. He convinced Khan to assume the name "John Harrison" and used him to create new ships and weaponry for Section 31 and Starfleet. Khan ends up resenting Marcus' control over him and attempts to smuggle his remaining crew members in experimental warhead prototypes, but is discovered and must escape alone and leave his crew members behind. Presumably killed by Marcus.
In the Prime Timeline, Kahn is awoken by the crew of the Enterprise after stumbling upon the SS Botany Bay and only after a malfunction with his cryotube did Kahn awake. Although he was not being used as a pawn in Marcus's plan, he still did considerable damage during his time with the crew of the Enterprise. After being defeated by Kirk, Kahn and his team of supermen are marooned on an uninhabited planet, only to reappear in "Star Trek II: The Wrath of Khan." In contrast, the events surrounding Kahn in "Star Trek: Into Darkness" happen in a more contained and slightly easier to handle way than in the Prime Timeline. He is captured by the Enterprise crew who hold him in captivity and keep him separated from his crew which he had hidden within the torpedos, not allowing him to awaken then. This leads the Enterprise crew to handle it more expediently and contain Kahn within a cryogenic tube, less likely that he will awaken to invoke another “Wrath of Khan.”
Now, time travel has always been a little wibbly wobbly within the Star Trek universe and any other science fiction media. There are some moments that state that once something in the past has changed, the previous timeline no longer exists. This theory is similar to the “Back to the Future” thought process where if you kill your father you will cease to exist. However, it is just as likely that all of these timelines can and do exist simultaneously. Prime Spock would no longer exist once the timeline has been altered, as the events leading up to his arrival would not remain the same, effectively causing a paradox. The only way for him to remain is if the new timeline was entirely separate and existed at the same time as Prime. The fact that there are these fixed points within the timeline definitely makes it seem like the other timelines must still exist in some capacity. If that is the case, then what other moments will we see that stand the test of timelines and have that high probability Data talks about? Hopefully, we will be seeing more movies from Abrams in the coming years to give us a little more insight into what the Kelvin Timeline has to offer!