The secret of Namibia's 'fairy circles' may be explained at last

Using computer models, ecologists think they have finally hit upon the reason for the strange polka dot patches scattered across the Namib desert

The marks on the ground in the Namib desert resemble a vast sheet of polka dots, or to the less romantic observer, perhaps a bad case of chickenpox.

In local myths, the bare, red circles fringed with grass are footprints of the gods, or patches of land once poisoned by the breath of a subterranean dragon. But even among scientists, who strive for more convincing theories, the curious, repetitive patterns have proved hard to explain.