Researchers surveyed 1,500 km of ancient Arabian desert and checked 125 sites, finding evidence of lakes at 55 but no early human tools; a new study suggests missing toolmaking stone mattered as much as water

• Scientists have made new discoveries about the Arabian peninsula.
• Simple fifth-grade science would have us believe that we need just three things to survive: air, water and food.
• So, when scientists discovered evidence of freshwater lakes across the interiors of the Arabian Peninsula, they expected to find traces of large prehistoric human settlements.