Continuous 1.3-million-year record of East African hydroclimate, and implications for patterns of evolution and biodiversity

Robert P. Lyons, Christopher A. Scholz, Andrew S. Cohen, John W. King, Erik T. Brown, Sarah J. Ivory, Thomas C. Johnson, Alan L. Deino, Peter N. Reinthal, Michael M. McGlue, Margaret W. Blome

Research output: Contribution to journalArticlepeer-review

47 Scopus citations

Abstract

The transport of moisture in the tropics is a critical process for the global energy budget and on geologic timescales, has markedly influenced continental landscapes, migratory pathways, and biological evolution. Here we present a continuous, first-of-its-kind 1.3-My record of continental hydroclimate and lake-level variability derived from drill core data from Lake Malawi, East Africa (9-15° S). Over the Quaternary, we observe dramatic shifts in effective moisture, resulting in large-scale changes in one of the world's largest lakes and most diverse freshwater ecosystems. Results show evidence for 24 lake level drops of more than 200 m during the Late Quaternary, including 15 lowstands when water levels were more than 400 m lower than modern. A dramatic shift is observed at the Mid-Pleistocene Transition (MPT), consistent with far-field climate forcing, which separates vastly different hydroclimate regimes before and after ∼800,000 years ago. Before 800 ka, lake levels were lower, indicating a climate drier than today, and water levels changed frequently. Following the MPT high-amplitude lake level variations dominate the record. From 800 to 100 ka, a deep, often overfilled lake occupied the basin, indicating a wetter climate, but these highstands were interrupted by prolonged intervals of extreme drought. Periods of high lake level are observed during times of high eccentricity. The extreme hydroclimate variability exerted a profound influence on the Lake Malawi endemic cichlid fish species flock; the geographically extensive habitat reconfiguration provided novel ecological opportunities, enabling new populations to differentiate rapidly to distinct species.

Original languageEnglish (US)
Pages (from-to)15568-15573
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume112
Issue number51
DOIs
StatePublished - Dec 22 2015

Keywords

  • Cichlid fish
  • East African rift
  • Lake Malawi
  • Quaternary
  • Tropical paleoclimatology

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Continuous 1.3-million-year record of East African hydroclimate, and implications for patterns of evolution and biodiversity'. Together they form a unique fingerprint.

Cite this