Final answer:
Australopithecus afarensis split into two groups: the gracile and the robust australopithecines. The gracile group includes species such as A. anamensis, A. afarensis, A. africanus, and A. garhi, while the robust group consists of the genus Paranthropus, including P. robustus, P. boisei, and P. aethiopicus.
Step-by-step explanation:
Australopithecus afarensis Evolutionary Divergence:
The species Australopithecus afarensis is an early hominin that lived approximately 3.9 to 2.9 million years ago. In the course of human evolution, A. afarensis is believed to have split into two groups: the gracile australopithecines and the robust australopithecines. Among the gracile species, which include Australopithecus anamensis, Afarensis, A. africanus, and A. garhi, A. afarensis is particularly notable for its bipedal locomotion, despite having some ape-like features such as long arms and curved fingers and toes. The robust australopithecines, classified under the genus Paranthropus, include species such as Paranthropus robustus, P. boisei, and P. aethiopicus. These two branches represent a significant divergence in early hominin evolution, with differences in both their physical characteristics and their possible ecological niches.