Extinction Y
All the pollutants and chemicals in the air released everywhere strengthened the X chromosome to the point where men didn't need women to reproduce with anymore. The pollutants and chemicals in the air everywhere also negatively impacted women across the world to where in the year 3037 women went extinct and so did the need for the Y chromosome. Men via other men get pregnant due to the new and improved Xxxxx chromosomes making it all possible. Men gave birth through the rectum and had not as much pain through the process.