Here is how I see the very base of evolution. It starts with a female who is a member of a species or a large group from a species that is not satisfied with their existence in their environment.
She is at one of the first of those moments during which she can become pregnant, and her body, knowing it is the optimal time to carry and deliver, is broadcasting to all of the males it can reach not only that she is ready, but that it wants particular genes that will give her progeny a more satisfying existence then she has had.
When her body finds the male that best fits it’s requirements it accepts the male for his sperm. If there are other needs a male must fulfill in order for the progeny to succeed, the female will accept the male’s further presence.
Over thousands of generations the physical structures of females use the available male genetic structures to eventually develop progeny satisfied with their existence in their environment. It can involve millions of years and result in severely different structures, which is what I call evolution, or it could involve things like beak changes back and forth during drought and wet times, which I call inherent traits rising and falling, as opposed to evolution which always results in greater complexity.