Austronesian together with East Africans arrived in Madagascar around 500 C.E. and dramatically changed the island's ecology, among other things, causing megafauna extinction. There is solid evidence of much more marginal human occupation that had only modest ecological impact about 2500 years before then (i.e. about 2000 BCE).
A new study argues that a couple of isolated elephant bird bones showing signs of cuts that look like they were butchered from ca. 8500 BCE, constitute evidence of a much earlier, if potentially even more marginal, early human occupation.
But, in the absence of corroboration in the form of stone tools or human remains or other more definitive evidence of a human presence, this find merely provides a plausible reason to look for more evidence rather than truly establishing a human presence. In my view, it is too easy for a rare outlier non-human caused event to look like a butchered bone for this thin evidence pushing back the earliest potential human occupation of the island by 6500 years, for this evidence alone to establish what it is trying to prove.
Previous research suggests that people first arrived on Madagascar by ~2500 years before present (years B.P.). This hypothesis is consistent with butchery marks on extinct lemur bones from ~2400 years B.P. and perhaps with archaeological evidence of human presence from ~4000 years B.P. We report >10,500-year-old human-modified bones for the extinct elephant birds Aepyornis and Mullerornis, which show perimortem chop marks, cut marks, and depression fractures consistent with immobilization and dismemberment. Our evidence for anthropogenic perimortem modification of directly dated bones represents the earliest indication of humans in Madagascar, predating all other archaeological and genetic evidence by >6000 years and changing our understanding of the history of human colonization of Madagascar. This revision of Madagascar’s prehistory suggests prolonged human-faunal coexistence with limited biodiversity loss.
J. Hansford et al. Early Holocene human presence in Madagascar evidenced by exploitation of avian megafauna. Science Advances. (September 12, 2018). doi:10.1126/sciadv.aat6925.