For most species in the animal kingdom, reproduction requires both a male and female but it appears that for a population of honeybees, this convention does not apply.
The isolated population of Cape bees in South Africa have evolved a strategy to reproduce without males.
The finding comes from a research team from Uppsala University in Sweden who studied the isolated population of Cape bees in South Africa.
They looked at the entire genome of a sample of Cape bees, and compared this with other populations of honeybees to try to understand the mechanism behind this asexual reproduction.
Matthew Webster, one of the researchers from Uppsala University, said: ‘The question of why this population of honeybees in South Africa has evolved to reproduce asexually is still a mystery. But understanding the genes involved brings us closer to understanding it.’
Most animals reproduce sexually, where both males and females are required to produce offspring.
Honeybees normally abide by this norm – the female queen bee lays eggs which are then fertilised by sperm from male bees known as ‘drones’.
However, one isolated population of honeybees living in the southern Cape of Africa has evolved a strategy to reproduce without males.
In the Cape bee, female worker bees are able to reproduce without a male by laying eggs that are essentially fertilised by their own DNA, which develop into new worker bees.
These bees are also able to invade the nests of other bees and continue to reproduce in this fashion, eventually taking over the foreign nests, in a behaviour called ‘social parasitism’.
Unfortunately, the explanation for this unique behaviour is unknown.
Mr Webster said: ‘There are a handful of genes where certain genetic variants are found at very different frequencies in Cape bees compared to other African honeybees.
‘For example variants in genes that affect cell division leading to egg production could explain how worker bees are able to lay eggs that develop into new worker bees, even though they are not fertilised.’
The researchers found striking differences in the genes of the Cape bees compared to other honeybee populations.
This could explain both the abnormal egg production without males, and the social parasitism.
Mr Webster said: ‘This study will help us to understand how genes control biological processes like cell division and behaviour.
‘Furthermore understanding why populations sometimes reproduce asexually may help us to understand the evolutionary advantage of sex, which is a major conundrum for evolutionary biologists.’