Darwin (Armando Muñoz) is a mutant character in the Marvel Comics Universe. He first appeared in X-Men: Deadly Genesis #2, and was created by writer Ed Brubaker and artist Pete Woods. Darwin was one of the "Missing X-Men".
After birth, Darwin's powers of self-protection and continuous circumstantial evolution made his mother hate him. The half-Black, half-Latino Darwin was found by some scientists who experimented on Darwin, bringing him to the attention of the public. He was found by Moira MacTaggert and recruited as one of her "fosters." He was in the first team, along with Kid Vulcan, Petra, and Sway to attempt to rescue the X-Men from Krakoa.
While Petra and Sway were killed by Krakoa, Darwin and Vulcan were swallowed in the earth by a combination of Sway and Petra's dying powers. Darwin absorbed the remains of the two girls and then converted himself into energy to fuse together with Vulcan. This gave Vulcan the powers of Darwin, Petra, and Sway. Rachel Summers managed to expel Darwin's presence from Vulcan, who then took off for space. While dealing with the shocking revelations of the truth about Krakoa and Vulcan, Beast found out that Darwin was still in fact alive. He was brought back to the Institute, where Beast determined Darwin is now a being of pure energy. While not conscious, he was shown to still have brain activity and was still alive, located at the X-Mansion. Once separated from Vulcan, Darwin's abilities caused him to develop a physical form once more.
When the Uncanny X-Men team (including Warpath, Havok, Polaris, Marvel Girl, Nightcrawler, and Professor Xavier) left to go hunt down Vulcan and stop him from destroying the Shi'ar, it was revealed that the Professor brought Darwin with them with hope that his friendship with Vulcan would help. When Shi'ar agents abducted Professor X, Darwin followed, and secretly jumped onto their spacecraft as it fled.
After successfully rescuing Xavier from his captors, Darwin was well on his way to freedom when D'Ken was revealed to be alive and well. Recaptured by the Imperium guards, Darwin failed in his attempt of rescuing his mentor and reluctantly accepted the Vulcan's offer of becoming Best Man at his and Deathbird's wedding.
Though obviously against the union, Darwin attended the wedding - albeit in shackles - and was caught in the crossfire when the X-Men and Starjammers attacked. Fearing his great day to be completely ruined by the interference, Vulcan trapped Xavier within the M'Kraan Crystal. Naturally fearing for his mentor's safety, Darwin followed Xavier into the depths of the crystal, and rescued him. He was taken to the X-Men's space ship with Professor X and Lilandra Neramani sent the ship on its way back to Earth.
Meanwhile, Darwin's father hires X-Factor Investigations to help him find Darwin because he feels bad for walking out on him and his mother when he was younger.
A possible reason for Darwin's skin changing color is given in X-Factor #33 by Monet. She thinks it might have something to do with the fact he is constantly in a state of evolution and his surroundings usually reflect the climate of the Europeans and to better adapt to the environment, has pale white skin.
After facing an intense wave of solar energy, Darwin once again has light brown skin. X-Factor #34