Humans, water, and the colonization of Australia.
The Pleistocene global dispersal of modern humans required the transit of arid and semiarid regions where the distribution of potable water provided a primary constraint on dispersal pathways. Here, we provide a spatially explicit continental-scale assessment of the opportunities for Pleistocene human occupation of Australia, the driest inhabited continent on Earth. We establish the location and connectedness of persistent water in the landscape using the Australian Water Observations from Space dataset combined with the distribution of small permanent water bodies (springs, gnammas, native wells, waterholes, and rockholes). Results demonstrate a high degree of directed landscape connectivity during wet periods and a high density of permanent water points widely but unevenly distributed across the continental interior. A connected network representing the least-cost distance between water bodies and graded according to terrain cost shows that 84% of archaeological sites >30,000 y old are within 20 km of modern permanent water. We further show that multiple, well-watered routes into the semiarid and arid continental interior were available throughout the period of early human occupation. Depletion of high-ranked resources over time in these paleohydrological corridors potentially drove a wave of dispersal farther along well-watered routes to patches with higher foraging returns.
College of Science and Engineering, James Cook University, Cairns, QLD 4870, Australia; Centre for Tropical Environmental and Sustainability Science, James Cook University, Cairns, QLD 4870, Australia; michael.bird@jcu.edu.au.
Michael I
0000-0003-1801-8703
MI
Bird
Astron Environmental Services, Perth, WA 6004, Australia; Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University, Cairns, QLD 4870, Australia.
Damien
D
O'Grady
Centre for Tropical Environmental and Sustainability Science, James Cook University, Cairns, QLD 4870, Australia; College of Arts, Society and Education, James Cook University, Cairns, QLD 4870, Australia.
Sean
0000-0001-6653-9963
S
Ulm
D001106:Archaeology; D001315:Australia; D005843:Geography; D063426:Human Migration; D006801:Humans; D008962:Models, Theoretical; D014867:Water; D062066:Water Resources
D014867:Water
Pleistocene colonization; Sahul; human dispersal; paleohydrological corridor; radiocarbon
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