That doesn't seem to be what the fossil record suggests. Gradual evolution is seldom seen in the fossil record.It's mind blowing how evolution explodes across a species all at once in unison to create a new species.
That's because is doesn't ... it starts with a single mutation in a single individual ... only this individual's offspring will carry the improved genetic material ... IF this mutation improves reproductive capacity, THEN the mutation will eventually spread throughout the population ... and this takes many many generations ...