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The Pyrenean ibex, an impressive mountain goat that lived in the central Pyrenees in Spain, went extinct in 2000. But a...
Tight budgets are forcing NASA to consider turning off one or more planetary science projects that have completed their...
Ebola is not a stranger to West Africa—an outbreak in the 1990s killed chimpanzees and sickened one researcher. But the...
In an as-yet-unpublished report, an international panel of geoscientists has concluded that a pair of deadly...
Tropical disease experts tried and failed before to eradicate yaws, a rare disfiguring disease of poor countries. Now,...
Since 2002, researchers have reported that agricultural communities in the hot and humid Pacific Coast of Central...
Balkan endemic kidney disease surfaced in the 1950s and for decades defied attempts to finger the cause. It occurred...
- 10 April 2014 11:44 am , Vol. 344 , #6180
- About Us
Beating Hybridization's Bad Rap
8 May 2001 7:00 pm
Mating with a member of another species is generally a bad idea. Cross a horse and a donkey, for example, and the offspring is sterile. But now, a study shows that some female birds can benefit by pairing with males of another species--as long as they sneak in some same-species matings on the sly.
The findings are based on 2 decades of research into Europe's pied flycatchers and collared flycatchers, two closely related species. Today, they interbreed rarely in two areas where their ranges overlap, the Swedish island of Gotland and the Czech Republic. Ben Sheldon of Oxford University, his student Thor Veen of Uppsala University, and researchers studying the birds in the Czech Republic decided to tease apart the costs and benefits of hybridization for female flycatchers.
When female collared flycatchers paired with male pied flycatchers, their offspring were somewhat less able to reproduce than the descendents of same-species pairs, the group found. But the females could compensate. First, breeding with a pied flycatcher occurred at a later time in the year, when chances of breeding success go up, possibly because food is more abundant. Through an unknown mechanism, the mixed pairs produced more male than female offspring, and males are more likely to survive. And the females secretly mated with males of their own species, such that half their young were pure collared flycatchers, cared for by the cuckolded pied flycatcher male.
All told, collared females can pass on more of their own genes at later dates in the breeding season by opting for pied males, the authors report in the 3 May issue of Nature--so long as they cheat on those males. The study sheds new light on the evolution of adultery in birds, Sheldon says. While previous studies have shown only very slight advantages to illicit matings, now "we have a situation where the advantages of this behavior can be huge."
The study boasts "huge sample sizes on something people usually dream of having a few cases of," says evolutionary biologist Dennis Hasselquist of Sweden's Lund University. And the outcomes "may alter the view of hybridization in animals as some form of mistake," comments Loeske Kruuk of the University of Edinburgh, "because it is now clear that we cannot take the consequences for fitness at face value."