29 January 2010
Vol 327, Issue 5965

About The Cover

Cover image expansion

COVER Spore-bearing fungal parasites emerge from the digested corpses of three bdelloid rotifers. These freshwater invertebrates (length <0.5 millimeters) present an evolutionary puzzle because they have reproduced without sex for millions of years but have not been driven extinct by relentlessly coevolving parasites. Bdelloids can escape fungal parasites in space and time through complete desiccation and dispersal by wind to uninfected habitats. See page 574. Image: Kent Loeffler, Kathie T. Hodge, Chris Wilson