When I taught physical, lo these many years ago, I started by showing the class the casts of modern human, Australopithecus and chimp innominates (one half of the pelvis). I asked students to divide the three specimens into two groups and state why they made the choice they did. All grouped human and Australopithecus together, with chimp as different, and based their choices on shape (morphology). Human and Australopithecus differ mainly in size, while both differ considerably from chimp in shape.
A simple but powerful lesson in how paleontologists and physical anthropologists work.
That's just microevolution