Alexandra Zachwieja

ALEXANDRA J. ZACHWIEJA, then a graduate student at University of Illinois, Urbana, Illinois, was granted funding in April 2018 to aid research on “Climate, Environment, and Competition Shaped Human Movement During the Initial Peopling of Australia,” supervised by Dr. Laura Shackleford. Ecological niche models (ENM) are a relatively new method in paleoanthropology. Predictions of hominin niches in Europe and Central Asia have shown that key predictor variables are temperature, precipitation, and access to fresh water. However, recent work has called for including biotic (species-interaction) data to construct more comprehensive models. Here, for the first time, researchers included estimates of human-carnivore competition from Late Pleistocene sites in ENM. Traditional environmental predictors were applied to Australasian landscapes during the Last Glacial Maximum (LGM) and validated using known fossil human occupation sites (n = 20) to construct human land preference maps in Maxent. Sources of assumptions and error became apparent in applying ENM to this long-standing temperate region. Only “distance to freshwater” remains an important traditional variable in this temperate context, followed by “slope.” Though competition across test sites was high, biotic data produced vague models, suggesting the need for additional species interaction data across the region. Despite well-fitting models (AUC = 0.891, AUC = 0.924), overall land preference estimates remain too broad for disentangling human dispersal routes in this region. Future analysis should focus on additional variables that may disproportionally affect human movement in temperate spaces (e.g., vegetation type and cover, sea-crossings, etc.)