Locate the origins of the most common honey bee species, the western honey bee (Apis mellifera) – sparked a long controversial debate among scientists. Some claim the bees are from Asia while others claim they are from Africa, but a new study may finally settle the dispute, reports Alison Bosman for Terre.com.
Scientists analyzed the genomes of 251 western bees comprising 18 different subspecies from Europe, Asia and Africa to reveal that this species is native to western Asia, Carissa Wong reports for New Scientist.
“We focused on obtaining samples from Africa and Asia, as they are generally under-represented [in studies of honeybee origins]senior author Kathleen Dogantzis, biologist at York University in Canada. With more representative samples in hand, the team was able to paint a better picture of the history of the western honeybee.
The study, published this month in Scientists progress, suggests that the western honeybee was born about 7 million years ago and spread west a million years later. Dogantzis tells New Scientist that previous estimates proposed that the subspecies evolved more recently – over the last million years or so – but that his team’s time frame is more precise since other studies have focused on when the species appeared instead of its evolutionary history.
In fact, the species has proliferated outside Asia on three occasions. In one case, they arrived in Africa; in a second outing, they entered Europe. By spreading to new habitats and adapting to different niches, the species eventually gave rise to seven different lineages of honey bees and 27 subspecies, which are now found on every continent, to the ‘except Antarctica, Terre.com reports.
But their ancestor is not the only common denominator these lineages share: each species and subspecies has the same set of just 145 genes, according to one Press release.
The 145 genes were linked to characteristics of worker bees, such as colony defense, immunity, and honey production, instead of queens, which lay eggs. Since workers do not reproduce, natural selection acts on them indirectly to improve the health of the colony as a whole. In a videoDogantzis says the genes were selected positively, meaning they were useful enough to spread throughout the population.
“We have very, very strong evidence that it is actually the ability of workers to change behavior and change calling behavior is the key trait that is really important for bees to survive in these different environments.” , co-author Amro Zayed, a biologist at York University, says in the video.
Dogantzis, Zayed and the team hope this new understanding of how the Western honeybee can adapt to the effects of climate change as well as commercial honey bee colonies.