Manuel is experiencing a mental disorder which is called the major depressive disorder. It has the capability of disrupting the activity of a person in terms of doing activities, disinterest in certain things that they used to live and even sleeping or the way they eat. It could be seen above as Manuel has less interest of the things he used to like and it also disrupts in his daily activities because of his moody character. The reason why it led him to experience it is because of his grand father's upcoming death.
If you mean germans, they shut down all jewish businesses and also made them wear stars of david on their chests to identify that they were jewish
Natural selection is the change of a species traits and characteristics over time to adapt to its environment. Over a period of time, the species will change and evolve because of its changing traits to adapt.
