When multiple sex prevents male extinction!
Promiscuous female fruit flies with high sex drives are key to preventing extinction of its male species, a study shows.
Flies in the northern parts of the US are more inclined to have multiple partners in order to reduce the occurrence of an X chromosome which causes the production of only female offspring.
With a view to replicating itself, SGE (selfish genetic element) genes, found in large numbers in many organisms, kill the sperm that carry the Y chromosome and the males with SGE produce fewer sperm.
Female fruit flies take advantage of this weakness by having several mates, increasing the chances that SGE-free males, with a higher sperm count, will father their offspring, said the study.
Female fruit flies have found a mechanism to limit the impact of SGE, said Thomas Price from the University of Liverpool in Britain.
The researchers proved a correlation between the number of mates and the prevalence of the SGE genes by collecting samples of fruit flies from seven sites in the US.
"If this particular SGE was to spread to every male in a population, then no more males would be born, and the population, or even the whole species, would become extinct," Price noted.
Females with a high sex drive and males with a high sperm count are keeping this species going, he added.
(Posted on 02-04-2014)