Final answer:
If Australopithecus africanus didn't collect the bones in the caves, the accumulation might be due to natural processes or scavengers, though Homo naledi's evidence points toward possible deliberate burials, suggesting advanced cognitive abilities in early human ancestors.
Step-by-step explanation:
If Australopithecus africanus did not collect the bones in the caves, then the scattering of the bones could have been the result of scavengers or natural death processes similar to those of cave-dwelling baboons. However, in the case of Homo naledi, the bones in the Rising Star cave system show evidence that could point to deliberate burial practices. This conclusion comes from the observation that Homo naledi bones appear to be deposited without gnawing marks from predators and lack sediment layers indicative of flood deposits - signs that often accompany natural accumulation events. Moreover, additional research shows that at another site, Sima de los Huesos, the remains of Neanderthal and Homo heidelbergensis also display patterns that could suggest scavenging mixed with potentially deliberate burial actions.
Fossil sites like the Rising Star cave and the Sima de los Huesos provide crucial insights into the behaviors of extinct hominin species. Scientists, including Lee Berger, continue to investigate such sites to determine if the skeletal deposits are indeed evidence of complex behaviors like intentional burial, which would indicate advanced cognitive abilities not previously attributed to early human ancestors. The answers to these questions may help reshape our understanding of the evolution of human rituals and social behaviors.