Get reliable science

African lakes show considerable dynamism over a range of timescales, underlining the large changes in precipitation-evaporation balance that have characterized Quaternary climates in Africa. On a late-Quaternary timescale, much of tropical Africa is in a relatively arid phase. Lake basins in the Sahara and Sahel region are dry or nearly so, but in the early Holocene they were full and played an important role in a productive landscape that supported Neolithic populations across wide regions that are now arid desert. At the Late Glacial Maximum (LGM), most lake records indicate low stands and heightened aridity. This long-term trend in moisture is partly due to orbital insolation variations driving a much stronger monsoon in the Northern Hemisphere during the early and mid-Holocene, compared with periods before and after. The glacial-interglacial transition was characterized by rising lake levels across much of the continent, but transgressions show marked reversals that appear related to large-scale dynamics such as changes in the thermohaline circulation and fluctuations in sea-surface temperatures. High-resolution lake-level records from the late Holocene in east Africa show a pattern of intense, multidecadal droughts, far more severe than any experienced in the twentieth century. The large fluctuations experienced by African lakes and their associated climatic causes have wide-ranging implications for human cultural evolution and well-being; they have also driven spectacular evolutionary radiations, as exemplified by the endemic Cichlid species flocks of African Great Lakes.