what does tattersall mean by saying that the australopiths“had hit upon a unique solution to the challenges of living and moving” in a new environment? That they presented an anatomical”configuration unlike anything else we know?

1.what does tattersall mean by saying that the australopiths“had hit upon a unique solution to the challenges of living and moving” in a new environment? That they presented an anatomical”configuration unlike anything else we know?2. What does tattersall mean by saying that the emergence of our species was a singular event?