Monogamy Has Its Rewards...( onogamous males Holland toldlast week...)

Monogamous females, in turn, proved more susceptible than their polygamous cousins to the seminal fluid toxins of normal males, Holland found. In other words, evolution stripped away much of their resistance.

To see the overall result of relaxing the arms race, Holland raised flies from each of the four lines under identical conditions. In every case, flies from monogamous lines produced more offspring than those from polygamous lines. That was a surprise, since biologists have usually assumed that competition leads to the selection of the fittest mates, leading to a net benefit from mate choice-not a net cost.

The work is elegant, says Michael Rose, an evolutionary biologist at the University of California at Irvine. He says it raises new questions about exactly how the adaptations arise: "The next step is breaking apart the seminal fluid toxicity and looking for the specific genes involved."

Author: Bob Holmes

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Contact: Claire Bowles
claire.bowles@rbi.co.uk
44 171 331 2751
New Scientist
1-Jul-1998