The origin of the western honey bee Apis mellifera has been intensely debated. Addressing this knowledge gap is essential for understanding the evolution and genetics of one of the world’s most important pollinators.
Where the common western honeybee originated from has long been a bone of contention amongst experts. So, to help put the argument to bed, scientists have now analyzed the genomes of 251 western honeybees encompassing 18 different subspecies from across Europe, Asia and Africa.
"We focused on getting samples from Africa and Asia, because they’re generally under-represented [in studies of honeybee origins]," says lead author Kathleen Dogantzis, a biologist at York University in Canada. With more representative samples in hand, the team was able to paint a better picture of the western honeybee's history.
The study, published this month in Science Advances, suggests the western honeybee originated around 7 million years ago in western Asia and expanded westward a million years later. Dogantzis tells New Scientist that previous estimates proposed that the subspecies evolved more recently - within the last million or so years - but that her team's timespan is more accurate since the other studies focused on when the species appeared instead of their evolutionary history.
In fact, the species proliferated out of Asia three times. In one event, they made it into Africa; in a second exit, they moved into Europe. As they spread into new habitats and adapted to different niches, the species ultimately gave rise to seven different honeybee lineages and 27 subspecies, which are now found on every continent except Antarctica.
So now you know, they originated 7 million years ago in western Asia. But, rather remarkably, their ancestor isn't the only common denominator these lineages share: each species and subspecies have the same set of only 145 genes.