Code associated to the paper "Environmental conditions shaped the patterns of initial expansion by anatomically modern humans" by Frédérik Saltré, Joël Chadœuf, Thomas Higham, Monty Ochocki, Sebastián Block, Ellyse Bunney, Bastien Llamas, and Corey J. A. Bradshaw
This code and these data reproduce the results in the paper
The ability of our ancestors to switch food sources and to migrate to more favourable environments quickly enabled the rapid global expansion of anatomically modern humans beyond Africa as early as 120,000 years ago1. Whether this versatility was largely the result of environmentally determined processes1-4 or was instead dominated by cultural drivers, social structures, and interactions among different groups5 is unclear6. We developed a new statistical approach that combines both archaeological and genetic data to infer the most-likely initial expansion routes in Eurasia and the Americas. We then quantified the main differences in past environmental conditions between the most-likely routes and other potential (less-likely) routes of expansion. We established that, even though cultural drivers remain plausible at a finer scales, the migration corridors are predominantly constrained by a combination of particular regional environmental conditions, including the presence of a forest-grassland ecotone, changes in temperature and precipitation, and proximity to rivers.
Models: provides the (R and Matlab) code and data to infer the regional timing of initial human arrival and human movement pathways between seven sets of two locations each (i.e., a source and destination that represented the extremes of movement pathways across a continent)
Environmental_Variables: provide Matlab code and data to generate the distance to the nearest river, distance to cost and ruggedness layers used in the manuscript to run the statitical analyses.
Genetic_data: includes a total of 67,643 human mitochondrial control region sequences from Genebank (last accessed 28 May 2017, the last available update in the regions of interest)
IceSheet&River_data: provides the dataset (shapefiles) usedto genertae the layer of river and icesheet extent
Source_data: provides raw data and R/Matlab code to generate: Figures 1 & 2, FigS2 and S7, and Table S2
Statistical_analysis: provides the R/Matlab code to reproduce the Gloabl and Regional Ranomisation test
Contact: Dr Frederik Saltre, Research Fellow in Ecology College of Science and Engineering Flinders University Adelaide, South Australia e-mail: frederik.saltre@flinders.edu.au URL: http://GlobalEcologyFlinders.com
