The answer lies in their chromosomal makeup.

Warning: This article does contain spoilers for The Flash (2023). If you are in any way interested in superheroes or movies in general you'll no doubt be aware that a new comic book film is being released this week concentrating on the DC character The Flash. It's the first time the scarlet speedster has ever been given a solo movie and despite the controversy surrounding the film's lead star, Ezra Miller, Warner Bros have invested a lot into making this a thrilling experience for fans. The premise of the film is a loose adaptation of the 2011 comic Flashpoint, where The Flash travels back in time to prevent the untimely death of his mother but inadvertently changes the future, as is often the case with time travel movies. As a result, Michael Keaton will be reprising his iconic performance as Batman, a character he hasn't played since 1992 with the likes of Michael Shannon also returning as General Zod and Sasha Calle also delivering a new take on Supergirl. However, people who have already seen the film have noted that several other iconic iterations of these famous characters also make appearances despite some of the actors having already passed away. Many of these are included in the film's climax and feature CGI incarnations of beloved actors like Christopher Reeve as Superman and Adam West as Batman. Other cameos include George Reeves as the Superman from the 1950s, Helen Slater from the 1984 Supergirl movie, Nicolas Cage playing Superman from the unreleased 1990s film and George Clooney reprising Batman from the much maligned 1997 Batman and Robin movie. While The Flash isn't the first movie to use this type of technology (numerous Star Wars titles have already recreated the likes of Carrie Fisher and a younger Mark Hamill for new stories) the use of Reeve's Superman has struck a particularly sour note due to both the messaging and the apparent ugly aesthetic. While Warner Bros is likey to have gotten permission from Reeve's estate to include his likeliness in the film many fans feel that it sets the wrong precedent given that the actor was left paralysed in 1995 before passing away in 2004. Fans of the Superman TV show Smallville have pointed to Reeve's cameo in the show in a 2003 episode which didn't hide his paralysis but respectfully recognised his contribution to the character's legacy and also allowed him to promote his paralysis charity. George Reeves inclusion has also sparked controversy given that the actor ultimately blamed playing Superman for the downfall of his career. His death in 1959 also remains with debates raging over whether he was murdered or took his own life. Given that Reeves is perhaps the least known of all the cameos, fans who have dug into his backstory were shocked that he was included. Ultimately, Warner Bros' owns the rights to Superman and essentially can do whatever they want to with the character but with the growing popularity of multiverses and an over reliance on nostalgia this type of thing will only become more and more common. One thing that we can hope for is that if the technology continues to be used then the tributes will be more tasteful and considered than this time around. Have your say in our news democracy. Click the upvote icon at the top of the page to help raise this article through the indy100 rankings.

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