Man is the result of a purposeless and materialistic process that did not have him in mind. He was not planned.
Recognition of this kinship with the rest of the universe is necessary for understanding him, but his essential nature is defined by qualities found nowhere else, not by those he has in common with apes, fishes, trees, fire, or anything other than himself.
Now we do have many examples of transitional sequences.
Almost all paleontologists recognize that the discovery of a complete transition is in any case unlikely.
Certainly paleontologists have found samples of an extremely small fraction, only, of the earth's extinct species, and even for groups that are most readily preserved and found as fossils they can never expect to find more than a fraction.