Figure 5
Migration pathways that best explain genetic affinity between modern Caucasians and ancient humans, showing least-cost paths from Eurasian and African ancient populations (shown in the main map, see Table 2 for details) to the current Caucasian populations (identified in the inset map, see Table 1 for details). The least-cost paths imply that (1) human movement is impeded by terrain ruggedness (TRI), (2) the Bosporus-Dardanelles and the English Channel do not act as barriers, (3) swamps, glaciers and desert are not full barriers, but permeable at the highest of the cost grid values, and (4) riversides in desert are permeable at TRI values. It is assumed that most human movements occurred during climate warming events when the earth’s surface was not dramatically different from that of today, and hence the current data of the geographic features are used in the calculation of the least-cost paths. The map is generated using QGIS Desktop 3.10.6-A Coruña (https://qgis.org).
