Summary: 31 OCTOBER 2003 VOL 302 SCIENCE www.sciencemag.org774
Even as the bride and groom walk down
the aisle, they--or at least their guests--
know that marital bliss can be short-lived.
Wrinkles can appear in the smoothest rela-
tionships and turn lovers into adversaries.
Biologists are now realizing that the same
holds true in symbiotic relationships. What
starts out as a mutually beneficial arrange-
ment can turn into a commensal one, in
which just one partner benefits. In the
worst case, one symbiont begins to para-
sitize the other. But sometimes the partners
work through adversity to restore balance
in their alliance.
A new awareness of the complex-
ity of these interactions is shaking up
the ecology and evolutionary biology
communities, which are used to