WASHINGTON (AP) — The forces behind the mysterious "fairy circles" that dot a desert in southern Africa do not appear to be supernatural, but they are intricate and complex.

The formations are circles of land dozens of feet wide that create a stunning pattern in the Namib desert and have mystified locals and scientists for ages. Inside the circles it looks like nothing is growing, while plants grow well on the land surrounding them. Similar patterns have also been seen in Australia.

Paranormal powers like fairies and even dragon breath have been credited with creating them. But Princeton Unive...