In a world witnessing ever-increasing cultural change, a major challenge for ethnoastronomers is to document the dynamics of indigenous astronomical systems before the last custodians of this information die without passing on their knowledge to younger generations. This is a major global issue for astronomy. Yet such studies merely pinpoint one moment in time and present static views of astronomical systems. They take no account of the fact that, like the cultures of which they are a component, these astronomical systems are dynamic and change with time. In this paper we present case studies from South and SE Asia and from Oceania that demonstrate the close linkages between human ecology and indigenous astronomical systems. We then outline our attempts to use multidisciplinary data drawn from anthropology, astronomy, genetics, geology, hominid paleontology, paleoclimatology and prehistory in order to delineate changes that must have taken place in astronomical systems over the past 40,000 years in response to environmental, phylogenetic and religious changes. Within the international astronomical community, we refer to this new research methodology as ‘Multidisciplinary Ethnoastronomy’.