Question regarding genetics

I know most of the textbook information as I already finished my genetic course. However, I wonder if mutation is the raw source of evolution, why would one mutant create a whole new population? It's not individuals that survive but the species and populations that do, so let's say if one male raccoon mutates in a specific way that benefits itself, how can it pass on those traits to its offspring? Wouldn't the whole reproduction process with female be incompatible?

Evolution is fueled by three forces; variability, inheritability and differential survivability. Mutations are a very important source of variability. Let's use coat color as an example. The wild type color of mouse fur is a sort of brown. That color is produced by pigments that are coded for in the DNA. If a mutation to that gene occurs, it may cause a big change in the formula for the pigment that causes a white or yellow or black mouse. Any time there is a spelling difference between one individual's gene and another's, that difference came from a mutation sometime in the past. Then we have INHERITABILITY and DIFFERENTIAL SURVIVABILITY. If a yellow mouse is born (because his gamete DNA had a mutation) and that year there is a fungus in the plants where he lives that turns the plants yellow, then he is going to have some really good cammo. Chances are good that he is going to avoid getting eaten by a coyote and have bunches of babies. His genes are going to show up in greater numbers in the next generation because his color is working so well and his "broken" copy of fur pigment is passed on to his offspring. Now, most mice will still be the wild brown color for many generations but, if the environment continues to favor yellow fur generation after generation eventually that will become the common color.

Most mutations either don't cause any appreciable change in the protein that is built. When the change is significant, it is usually bad and the embryo doesn't survive. Sometimes the change is significant but survivable and you have a new variant. Remember, we are talking about a very long time, with many many generations. The odds are small but the numbers are huge.