The Marvel Universe has long utilized a sliding timeline to allow for heroes created over half a century ago -- like Spider-Man and the Fantastic Four -- to still feel young and fresh today. However, in some parts of the Marvel multiverse, these heroes actually aged realistically.
"In the Best of Families" and Spider-Man: Life Story present two realities where the Marvel heroes actually get older, from the beginning of the Marvel era into the modern-day.
Earth 1961
While walking through Reed's lab in Fantastic Four Annual 1998 by Karl Kesel and Stuart Immonen, the Earth-616 Thing is teleported to Earth-98. Here, the Fantastic Four formed in 1961 in a bid to win the space race -- and have aged realistically.
By 1998, the original Fantastic Four have split apart, but remain close. Reed and Sue travel the galaxy in search of ancient mysteries and the Thing retires to Arizona with Alicia Masters. In their stead, Human Torch and Franklin Richards -- now going by the name Zero Man -- lead the team alongside Johnny's wife, Crystal, and their eldest child, Cosmic Ray. Ray can shape-shift and has embraced his heroic legacy. However, his rebellious sister Luna -- with controllable hair similar to Medusa and going by Spike -- lashes out at her family, including Ben.
Exploring the reality, Ben ends up at Avengers Mansion during an annual poker game between three other nigh-immortal heroes: Wolverine, Thor and Doctor Strange. Along with Thing, they don't age while the rest of their friends and loved ones do.
Through them, Thing learns the fate of many other heroes on Earth-98: Daredevil eventually retired from heroics and became Mayor of New York City. Bruce Banner died from a heart attack mid-transformation into the Hulk. Captain America sacrificed his life to prevent a terrorist attack, implied to be the Oklahoma City Bombings. Finally, Spider-Man is revealed to have been missing since 1973, disappearing from the public eye following the deaths of Gwen Stacy and the Green Goblin.
Returning to the rest of the FF, Ben is caught by surprise by Spike, who uses an anti-gravity disc to stall Ben. Both are shocked when Spike's boyfriend turns out to be a disguise of the Wizard. Leading the Frightful Five into an attack on the Fantastic Four, the Wizard is stopped when Spike is able to free Ben and allow him to join the battle. The conflict ends when Zero Man's powers are thrown out of control and the Fearsome Five are sucked into the Negative Zone.
Following the battle, Franklin's wife, Zawadi -- implied to be the daughter of Black Panther -- gives birth to their daughter, the future heir to Wakanda, N'Yami. Franklin decides to leave the Fantastic Four so they can raise the young girl (named N'Yami Richards) in her ancestral homeland and Thing is returned to his proper reality.
Spider-Man: Life Story
Spider-Man: Life Story by Chip Zdarsky and Mark Bagley features a world where many heroes began their careers in the early 1960s. Peter Parker was bitten by a radioactive spider in 1962 and quickly became Spider-Man. By 1966, this world's political theatre is far more complicated by the presence of superheroes in the Vietnam War: While Iron Man and Giant-Man provide assistance to the US Army, Captain America is so horrified by what he sees overseas that he becomes a "traitor" and starts fighting to protect the civilians caught up in the crosshairs.
After spending years working for Reed Richards -- who has become consumed with the Future Foundation that Sue left for Namor -- Peter is crushed by the death of Gwen Stacy in 1973 during a failed revenge by Harry Osborn for the arrest of his father years earlier.
The surviving clones of Peter and Gwen (now known as Ben and Helen) leave New York and Peter finds new love with Harry's ex, Mary-Jane. The pair have twins in 1984 -- Benjy and Claire -- but a series of trying events leads Mary-Jane to leave Peter. By 1995, Peter reunites with Ben, who's been serving as a hero in Chicago.
Doctor Octopus attacks both and tries to trick them into thinking Ben is the original Peter Parker -- secretly at the behest of Norman Osborn, as part of one last revenge against Spider-Man. Harry sacrifices his life to save Ben during this revelation. Peter confronts Norman and the Green Goblin has a fatal heart attack. Ben agrees to take over Peter's life and identity as Spider-Man, so Peter can step away from the responsibility and reunite with Mary-Jane and their children.
In 2001, following the 9/11 attacks (during which a visiting Peter Parker does his best to save lives), Secretary of Defense Tony Stark helps pass the Superhero Registration Act to fight in the War on Terror. His Avengers (War Machine, Black Widow, Iron Fist, Captain Marvel and She-Hulk) arrest most unregistered heroes, but face opposition from Captain America's rogue Avengers (Hawkeye, Luke Cage, Cloak, Dagger and Amadeus Cho).
When Morlun kills Ben in 2006, Peter is forced to reveal his identity and confront Tony once again. However, the on-going Civil War distracts Peter from Morlun, who instead targets Peter's family. Benjy is injured, but Claire is able to save his life -- albeit at the cost of Morlun's, who is accidentally impaled through the chest by a tree branch in the fight.
By 2019, the superhero Civil War leaves an opening for Doctor Doom to conquer Earth. Many of the heroes of Peter's generation -- including Captain America, Iron Man, Mister Fantastic and Jessica Jones -- are killed by Doom. As one of the last heroes of his era, Spider-Man guides other young heroes like Miles Morales, Kamala Khan and even Claire in resistance to Doom's rule.
Aboard a satellite base of Doom's, Peter and Miles are confronted by a Venom/Kraven hybrid. Peter eventually turns on Miles -- revealing he knows Doctor Octopus replaced the mind of the hero. The two battle but Peter -- along with the spirit of May Parker -- convince Otto to return Miles' body, while Peter and the symbiote sacrifice themselves to destroy the satellite and help end Doom's rule once and for all.