Insect 'incest' signals an end to males

Jul 15, 2011

( -- Evolution may lead to males disappearing as they are replaced by 'parasitic fathers' who infect their daughters at birth in order to mate with them.

The finding comes from Oxford University scientists studying how hermaphrodite , such as the scale insect Icerya purchasi, in which the same individual produces both and and mates with itself, might have evolved.

A report of the research appears in the August issue of The .

'It turns out that in these hermaphrodite insects are not really fertilizing their eggs themselves, but instead are having this done by a parasitic tissue that infects them at birth,' said Laura Ross of Oxford University's Department of Zoology, an author of the report. ‘It seems that this infectious tissue derives from left-over sperm from their father, who has found a sneaky way of having more children by mating with his daughters.'

'Of course, females might not be happy about this,' said Dr Andy Gardner of Oxford University's Department of Zoology, also an author of the report. 'So, we developed a mathematical model to find out when the female and the parasite will come into conflict, and when they will collaborate over this weird reproductive tactic, to understand how it evolves.'

The researchers found that, once the infection becomes endemic, females are more inclined to mate with their parasitic fathers in this way, because mating with a close relative ensures that they pass on more copies of their genes to future generations. As a consequence, regular males disappear altogether as they struggle to find willing mates.

'But some rare males do pop up now and again,' added Laura Ross. 'We are now planning experiments with them, to recreate the ancestral state of this species, in order to test aspects of the theory.'

Explore further: Study shows even newly hatched chicks have a left to right number space map (w/ Video)

Related Stories

The cost of keeping eggs fresh for mother cockroaches

Feb 26, 2007

One of the defining differences between the sexes is in the size of their gametes. Males make many tiny sperm while females make only a few large eggs. This suggests that sperm are cheap while eggs are expensive. ...

Sex is thirst-quenching for female beetles

Aug 28, 2007

Female beetles mate to quench their thirst according to new research by a University of Exeter biologist. The males of some insect species, including certain types of beetles, moths and crickets, produce unusually large ejaculates, ...

Good males are bad fathers

Jun 25, 2009

Contrary to predictions, males of high genetic quality are not very successful when it comes to fertilizing eggs. A new study on seed beetles by Swedish and Danish scientists Göran Arnqvist and Trine Bilde shows that when ...

Does promiscuity prevent extinction?

Feb 25, 2010

Promiscuous females may be the key to a species' survival, according to new research by the Universities of Exeter and Liverpool. Published today (25 February) in Current Biology, the study could solve the my ...

Recommended for you

Baleen whales hear through their bones

Jan 29, 2015

Understanding how baleen whales hear has posed a great mystery to marine mammal researchers. New research by San Diego State University biologist Ted W. Cranford and University of California, San Diego engineer ...

Starving honey bees lose self-control

Jan 29, 2015

A study in the journal of the Royal Society Biology Letters has found that starving bees lose their self-control and act impulsively, choosing small immediate rewards over waiting for larger rewards.

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Jul 15, 2011
Interesting. There are mites that are born as a clutch of females with a brother that inseminates them and then dies. Think of it as the long away around to "reinventing" asexual reproduction. That seems like a halfway step on the path of fully asexual insects as described above.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.