From about 4 mya to about 2.5 mya the fossil record contains evidence of at least two different types of confirmed hominins: the Gracile Group (Australopithecus afarensis in Central East Africa, Austrlopithecus africanus in South Africa and Australopithecus sediba in South Africa) and the Robust Group (Paranthropus aethiopicus in Central East Africa, Paranthropus boisei in Central East Africa and Paranthropus robustus in South Africa). In spite of their physical differences, these two groups appear to have shared the same regions for millions of years.
What are the physical characteristics of each group? How did these two different types of hominins manage to inhabit the same general areas? Discuss habitat adaptations, food sources, habitat overlaps, climate fluctuations, group size, physical size and anything else that you think might help explain the evidence in the fossil record.