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12 December 2013 1:00 pm ,
Vol. 342 ,
Evolutionary biologists have long studied how the Mexican tetra, a drab fish that lives in rivers and creeks but has...
Victorian astronomers spent countless hours laboriously charting the positions of stars in the sky. Such sky mapping,...
In an ambitious project to study 1000 years of sickness and health, researchers are excavating the graveyard of the now...
Stefan Behnisch has won awards for designing science labs and other buildings that are smart, sustainable, and...
The iconic 125-year-old Lick Observatory on Mount Hamilton near San Jose, California, is facing the threat of closure...
Recent results from the Curiosity Mars rover have helped scientists formulate a plan for the next phase of its mission...
A new, remarkably powerful drug that cripples the hepatitis C virus (HCV) came to market last week, but it sells for $...
In pretoothbrush populations, gumlines would often be marred by a thick, visible crust of calcium phosphate, food...
- 12 December 2013 1:00 pm , Vol. 342 , #6164
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Promiscuity Pays for Bumblebees
13 January 1999 7:00 pm
Planning to tell your children about the birds and the bees? Think twice. Queen bees are among the most wanton of animals, mating with up to 20 males on their wedding flight. In tomorrow's Nature, Swiss researchers claim to know why: The queen's promiscuity protects the bee colony from parasitic plagues.
Parasites and their hosts are engaged in a continuous evolutionary arms race. Each time a parasite evolves a new trick, the victims have to adapt by acquiring a new defense. Experts think this may be the reason why organisms have sex in the first place: If all your offspring are clones, all could be wiped out by a single disease. Mix your genes with those of a partner, and the genetic jumble will produce a hodgepodge of offspring, at least some of which may survive.
Similarly, mating with lots of other partners may be even better than putting all your eggs in one paternal basket, ecologists Paul Schmid-Hempel and Boris Baer of the Federal Institute of Technology in Zürich reasoned. To test this hypothesis, they artificially inseminated 19 queen bumblebees. Twelve received sperm from just a single drone, so their daughters would be full sisters. Seven others were treated to a four-male sperm cocktail, producing mixed broods of sisters and half-sisters. The researchers then let the queens found colonies in a meadow near Basel and kept track of how these fared.
The one-father colonies suffered from parasitism much more than the multifather ones. One parasite in particular, a single-celled creature called Nosema, was almost absent from the latter, while every bee in the one-father colonies carried at least one of them. Moreover, the multifather broods, being healthier, were also twice as prolific. The researchers are not sure how genetic diversity increases the colony's health; they think parasites simply may have a smaller chance of spreading. But whatever the mechanism, they say, the queen's promiscuity is probably an evolutionary adaptation to increase genetic diversity and prevent disease in the colony.
"It's a stunning result," says Curtis Lively, an evolutionary biologist who studies the benefits of sex at Indiana University, Bloomington, and "a clever experimental test of an evolutionary hypothesis."