Akatosh is the dragon god of time and they are the children of Akatosh, each with a soul lasting beyond the body. They are as they ever were. They're part of time. Akatosh is time, Alduin the firstborn they all followed once, who had mortals trembling or reaching up in worship was time laid out in a line, a time that begins and ends. There's no space to breed as a lesser thing does. They came from a god. A true god.