Arabia is a vast desert today. But times change all things and ages ago the climate was milder and wetter. Satellite images have revealed that a network of ancient rivers once coursed their way through the sand of the Arabian Desert, leading scientists to believe that the region experienced wetter periods in the past. The images are the starting point for a major potentially ground-breaking research project led by the University of Oxford into human evolutionary heritage. The research team will look at how long-term climate change affected early humans and animals who settled or passed through and what responses determined whether they were able to survive or died out.