Lovelorn
frogs hop into the gene pool
SPANISH
zoologists have discovered that male frogs who are losers in love
get their revenge by spreading their sperm over eggs that have been
left by a pair of romancing amphibians.
The
sneaky manoeuvre is dubbed "clutch piracy" by the researchers,
who say it sheds intriquing light on the principle of mate selection
among frogs and helps explain the creatures' wide genetic diversity.
Until
now, the common frog was believed to have a rather humdrum sex life.
The female chose a mate, who would then grasp her and, as she shed
a spherical batch of eggs, shed his sperm over the clutch.
After
a frantic froggy coupling, the couple would then seperate, leaving
the eggs to develop into tadpoles and the nintro frogs.
But
observations made by University of Vigo frog-watcher David Vieties
show that, once the blissful pair are out of sight, a pirate often
moves in, shedding his own sperm over the egg clutch.
The
findings weaken theDarwinian idea of mate selection - that the female
chooses a single male with the best genetic selection and mates
only with him in order to reproduce.
In
this case, the big winner is the pirate frog, who gets the chance
of fertilising some eggs even though he lost out in the mating competition.
But
the female, too, is also a beneficiary, because her eggs get a better
chance of being fertilised, the researchers say. The study is published
in Nature, the British weekly scientific journal. - AFP
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