“…The detailed process of this population movement is unclear (Sheppard, 2011), as are likely reasons for it. Different explanations have been proposed, summarised as push and pull factors (Lilley, 2000), such as demographic pressures (Bellwood, 2011), environmental disasters (Grattan and Torrence, 2007), and the search for pristine environments with abundant food resources (Lilley, 2019). Each of these reasons might have played a part at some stage in the process, but the archaeological record is unlikely to preserve clear evidence for them (Kirch, 1997: 253; see also Anthony, 1990).…”