Parton and colleagues writing in Geology, present a unique alluvial fan aggradation record from southeast Arabia spanning the past approx. 160,000 years. Situated along the proposed southern dispersal route, the Al Sibetah alluvial fan sequence provides a unique and sensitive record of landscape change in southeast Arabia. This record is to date the most comprehensive terrestrial archive from the Arabian Peninsula, and provides evidence for multiple humid episodes during both glacial and interglacial periods. Evidence from the Al Sibetah alluvial fan sequence indicates that during insolation maxima, increased monsoon rainfall led to the widespread activation of drainage systems and grassland...