BBC Homepage World Service Education
BBC Homepagelow graphics version | feedback | help
BBC News Online
 You are in: Sci/Tech
Front Page 
World 
UK 
UK Politics 
Business 
Sci/Tech 
Health 
Education 
Entertainment 
Talking Point 
In Depth 
AudioVideo 

Monday, 21 August, 2000, 21:24 GMT 22:24 UK
Fishy clue to promiscuity
Guppy
Given the choice, female guppies prefer to mate with several males
A study of female guppies could solve a long-running mystery of evolution - why some female animals have multiple partners.

The answer could be that they have more offspring and that those young were better at escaping predators.

But the researchers behind the study say the explanation probably does not apply to mammals, and certainly not to humans.

Biological puzzle

Biologists have already come up with an explanation for why some male animals are promiscuous - they sire more offspring, preserving the diversity of the gene pool.

But the reasons for females exhibiting the same behaviour were not clear, particularly as they might risk being eaten by predators.

"The benefits of promiscuity for males are very clear," Dr Anne Magurran, of the school of Environmental and Evolutionary Biology at St Andrews University told BBC News Online.

"But the advantages for females are less well demonstrated."

The team studied guppies caught in the wild in Trinidad.

'More and fitter'

They found females that had mated with several males gave birth to more and fitter offspring compared with those that had mated with a single partner.

The young were also born sooner and were better at escaping predators, giving them an evolutionary advantage.

She said this explanation for female promiscuity could extend to other members of the animal kingdom, such as birds and reptiles.

But it probably did not apply to mammals, she said.

"Clearly it doesn't apply to humans because humans don't have multiple broods," added Dr Magurran.

The work is published in Monday's edition of the Proceedings of the National Academy of Sciences of the United States of America.

Search BBC News Online

Advanced search options
Launch console
BBC RADIO NEWS
BBC ONE TV NEWS
WORLD NEWS SUMMARY
PROGRAMMES GUIDE
See also:

01 Mar 00 | Sci/Tech
Feathers fly in the mating game
17 Mar 00 | Sci/Tech
Discovery challenges snake origins
30 Sep 99 | Sci/Tech
Frogs kiss and tell
Links to more Sci/Tech stories are at the foot of the page.


E-mail this story to a friend

Links to more Sci/Tech stories