Retracing the dispersal of rainforest food trees by east Australian Indigenous Peoples with genomic data

Over millennia, Indigenous peoples have dispersed the propagules of non-crop plants intentionally or accidentally via trade, seasonal migration or attending ceremonies. This has potentially increased the geographic range or abundance of many “wild” edible plant species around the world. However few phylogeographic studies have investigated anthropogenic dispersal as a factor of the distribution and demographic history of plant populations. It remains a challenge to separate the signal of anthropogenic versus non-anthropogenic dispersal with genomic data alone. This thesis showcases multidisciplinary research that incorporates plant genomics, historical research, and collaboration with Indigenous Biocultural Knowledge (IBK) holders to retrace the dispersal of culturally significant and edible rainforest trees by Indigenous Peoples in eastern Australia.

Chapter 1 outlines the development of an ethical and culturally appropriate research protocol for collaboration with First Nations peoples. Chapter 2 outlines a genomic screening method that can be used to identify non-crop plant species with edible fruit that show putative signals of dispersal by ancient Indigenous peoples. Chapter 3 revealed genomic patterns within Araucaria bidwillii (Bunya Pine) consistent with IBCK evidence that pre-colonial and colonial First Nations peoples translocated the species in its southern range. Chapter 4 demonstrated genomic evidence that First Nations peoples facilitated an upland expansion of Castanospermum australe (Black Bean) in its southern range. These findings illustrate that plant genomics can be deployed as a tool to rediscover Indigenous histories disrupted by colonial dispossession. It also yields insights to the long-term demographic and evolutionary impacts of plant translocations and raises questions about restoration goals and values.