According to the findings of a new study by a team of researchers, led by Dr Matthew Gage of UK’s University of East Anglia (UAE), female promiscuity is essentially a result of inbreeding.

During the course of their of lab-based as well as natural populations of red flour beetles, the researchers found that the population drops, which these beetles often undergo, result in severely inbred communities. Breeding with close relatives leads female red flour beetles to a promiscuous mating behaviour, which brings about an increase in the offspring numbers.

In their study - published in the journal Science – highlighting the key reason why the females of some species mate with more than one male, the researchers noted that the females can apparently avoid the ill-effects of inbreeding as they expose themselves to a bigger pool of sperm --- from which they select the ones that are more genetically dissimilar to them for fertilising their eggs.

In addition, the researchers at UAE also found that females in these inbred populations showed a comparatively higher inclination for mating, as compared to those females who did not have to face a bottleneck situation.

In order to explain the raison d'être behind the increase in unbridled mating, the researchers further pointed out that inbred females mostly left two times the number of descendents as those females which mated with only one male.

Commenting on the findings, Dr Gage said: “It is quite easy to imagine how promiscuity could spread through the population if promiscuous females leave more descendents.”