Commensals/Domesticates on Rapa Nui: What Can Their Phylogeographic Patterns Tell Us About the Discovery and Settlement of the Island?

Rapa Nui is one of the smallest, most remote, and isolated landmasses in the world to have already been settled when European explorers arrived in the eighteenth century. The first people to arrive on Rapa Nui were Polynesians thought to have island-hopped from east Asia (mitochondrial origin in southern China, Ko et al. 2014; Bellwood et al. 2017; language origin in Taiwan, Gray et al. 2009, Klamer 2019; nuclear genome origin in southern China, Yang et al. 2020) over many generations across Oceania to arrive on Rapa Nui approximately 750 years ago (Wilmshurst et al. 2011). The navigational achievements of the Polynesians simply to reach Rapa Nui, let alone persist on it, were extraordinary. Whether or not further eastward exploration included contact with pre-European South America, with accompanying gene flow between the Rapa Nuians and South Americans or only the trade of goods, is still up for debate. Either way, the transportation of animal and plant species undoubtedly proved essential to early Polynesian survival in both Near Oceania (defined as a region of the Pacific that includes New Guinea, the Bismarck archipelago, and the Solomon Islands that was settled 35,000 years ago) and Remote Oceania (defined as the islands east of the Solomon Islands that were settled from 3000 to 3500 years ago).