The gradual establishment of the 100,000-year pattern of glacial cycles in the mid-Pleistocene created a long interval of instability in Africa's climate that posed new selective pressures for hominin societies. Integrated technological, social, neurological, and genetic changes effectively broadened the range of habitats in which Homo erectus and its descendants lived, with many of these developments taking place in response to the variability of mid-Pleistocene climates. The archaeological record in particular shows the application of technological solutions by H. erectus and, later, by Homo heidelbergensis to challenges of mobility linked to shifting resource distributions. These patterns of integrated behavioural and biological change provide a framework for assessing the impact of climate change on hominin evolution to the end of the mid-Pleistocene and through the start of the late Pleistocene (~430–70 kya, MIS 12-MIS 5a). This relatively short period encompasses significant changes in technology and other behaviours, as well as the evolution of the anatomically modern human form. The innovation of composite tool technologies (Mode 3) took place ~300 kya, and before the evolution of Homo sapiens ~200 kya, though for some a correspondence may exist between the appearance of Mode 3 and the evolution of Homo helmei, a putative ancestor of H. sapiens. Regardless of the species involved, Mode 3 makers developed the first distinctive regional artefact styles in the form of bifacial points, and the earliest archaeological indicators of symbolic expression.