<span>This would be called an aura. An aura is simply some sort of disturbance that is experienced by people who have migraines or seizures. It is something they sense, see or smell prior to the headache or seizure beginning. Sometimes it is a strange light or a foul odor, sometimes it can even be confusing thoughts. Generally, those who experience auras will have the same aura each time.</span>
Species change over time. -The mechanism that produces the change is natural selection: the differential survival and reproduction of individuals based on variation in their traits. Natural selection acts on individuals but individuals do not evolve; their descendants do.