Lake Malawi 1.2 Million Year Ostracod and Geochemical Lake Level Data Ivory, S.J.; Blome, M.W.; King, J.W.; McGlue, M.M.; Cole, J.E.; Cohen, A.S. Ivory, S.J. Blome, M.W. King, J.W. McGlue, M.M. Cole, J.E. Cohen, A.S. Other Hydroclimate Reconstruction earth science/paleoclimate/paleolimnology (ostracod index,sediment,null,count per gram,null,paleolimnology,null,microscopy,N,broken ostracod valves) earth science/paleoclimate/paleolimnology (ostracod index,sediment,null,count per gram,null,paleolimnology,null,microscopy,N,carbonate coated ostracode valves) earth science/paleoclimate/paleolimnology (identified chlorophyte,sediment,null,count per gram,null,paleolimnology,log-transformed,microscopy,N,botryococcus) earth science/paleoclimate/paleolimnology (quartz,sediment,null,count per gram,null,paleolimnology,null,microscopy,N,null) earth science/paleoclimate/paleolimnology (siderite,sediment,null,count per gram,null,paleolimnology,null,microscopy,N,null) earth science/paleoclimate/paleolimnology (total ostracods,sediment,null,count per gram,null,paleolimnology,log-transformed,microscopy,N,null) earth science/paleoclimate/paleolimnology (lake level,null,null,dimensionless,null,paleolimnology,null,microscopy,N,reconstruction based on PCA of above fossils; low values are high lake levels) earth science/paleoclimate/paleolimnology (identified ostracod,null,null,count per gram,null,paleolimnology,null,microscopy,N,Candonopsis) earth science/paleoclimate/paleolimnology (ostracod index,sediment,null,count per gram,null,paleolimnology,null,microscopy,N,whole ostracod valves) earth science/paleoclimate/paleolimnology (charcoal,sediment,null,count per gram,null,paleolimnology,log-transformed,microscopy,N,null) earth science/paleoclimate/paleolimnology (pyrite,sediment,null,count per gram,null,paleolimnology,null,microscopy,N,null) earth science/paleoclimate/paleolimnology (vivianite,sediment,null,count per gram,null,paleolimnology,null,microscopy,N,null) earth science/paleoclimate/paleolimnology (ostracod index,sediment,null,count per gram,null,paleolimnology,null,microscopy,N,adult ostracods) earth science/paleoclimate/paleolimnology (identified ostracod,null,null,count per gram,null,paleolimnology,null,microscopy,N,Cypridopsines) earth science/paleoclimate/paleolimnology (identified ostracod,null,null,count per gram,null,paleolimnology,null,microscopy,N,Ilyocypris) earth science/paleoclimate/paleolimnology (depth,null,null,meter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (fish index,sediment,null,count per gram,null,paleolimnology,log-transformed,microscopy,N,fish bones) earth science/paleoclimate/paleolimnology (identified midge,sediment,null,count per gram,null,paleolimnology,log-transformed,microscopy,N,chaobrids) earth science/paleoclimate/paleolimnology (identified ostracod,null,null,count per gram,null,paleolimnology,null,microscopy,N,Sclerocypris) earth science/paleoclimate/paleolimnology (identified ostracod,null,null,count per gram,null,paleolimnology,null,microscopy,N,Gomphocythere) earth science/paleoclimate/paleolimnology (ostracod index,sediment,null,count per gram,null,paleolimnology,null,microscopy,N,oxidation stained ostracode valves) earth science/paleoclimate/paleolimnology (ostracod index,sediment,null,count per gram,null,paleolimnology,null,microscopy,N,reduction stained ostracode valves) earth science/paleoclimate/paleolimnology (mica group,sediment,null,count per gram,null,paleolimnology,null,microscopy,N,null) earth science/paleoclimate/paleolimnology (age,null,null,calendar kiloyear before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (identified ostracod,null,null,count per gram,null,paleolimnology,null,microscopy,N,Limnocythere) earth science/paleoclimate/paleolimnology earth science/paleoclimate/paleolimnology (Lake Malawi, core GLAD7-MAL05-1>LATITUDE -11.29389>LONGITUDE 34.43722) Long paleoecological records are critical for understanding evolutionary responses to environmental forcing and unparalleled tools for elucidating the mechanisms that lead to the development of regions of high biodiversity. We use a 1.2-My record from Lake Malawi, a textbook example of biological diversification, to document how climate and tectonics have driven ecosystem and evolutionary dynamics. Before ~800 ka, Lake Malawi was much shallower than today, with higher frequency but much lower amplitude water-level and oxygenation changes. Since ~800 ka, the lake has experienced much larger environmental fluctuations, best explained by a punctuated, tectonically driven rise in its outlet location and level. Following the reorganization of the basin, a change in the pacing of hydroclimate variability associated with the Mid-Pleistocene Transition resulted in hydrologic change dominated by precession rather than the high-latitude teleconnections recorded elsewhere. During this time, extended, deep lake phases have abruptly alternated with times of extreme aridity and ecosystem variability. Repeated crossings of hydroclimatic thresholds within the lake system were critical for establishing the rhythm of diversification, hybridization, and extinction that dominate the modern system. The chronology of these changes closely matches both the timing and pattern of phylogenetic history inferred independently for the lake's extraordinary array of cichlid fish species, suggesting a direct link between environmental and evolutionary dynamics. STUDY NOTES: Ostracod assemblage and sediment mineralogy data with lake level reconstruction for Lake Malawi, for the past 1.2 million years NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Ivory, S.J. Investigator : Blome, M.W. Investigator : King, J.W. Investigator : McGlue, M.M. Investigator : Cole, J.E. Investigator : Cohen, A.S. 2018-07-18 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/24631 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/malawi2016ost.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/malawi2016ost.txt English https://www.ncdc.noaa.gov/paleo/study/24631 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/malawi2016ost.txt Sarah J. Ivory, Margaret W. Blome, John W. King, Michael M. McGlue, Julia E. Cole, and Andrew S. Cohen2016Environmental change explains cichlid adaptive radiation at Lake Malawi over the past 1.2 million yearsProceedings of the National Academy of Sciences1134211895-1190010.1073/pnas.1611028113http://www.pnas.org/content/113/42/11895 START YEAR: 1219118 cal yr BP * END YEAR: 10475 cal yr BP 34.43722 -11.29389 34.43722 -11.29389