By Carissa Wong.
The bees are honey bee workers.
Kim Taylor is a naturepl.com employee.
The western honeybee, which lives across Europe, Africa and Asia, first evolved in western Asia. Understanding the evolution of honeybees can help us protect them.
The western honeybee species is thought to have originated in south-east Asia, but whether it evolved from an ancestral honeybee in Asia or after it had spread to Africa is a question that is debated.
Kathleen Dogantzis and her colleagues at York University in Canada analysed the genomes of 251 western honeybees and found 18 different types.
The western honeybee species first evolved in western Asia before spreading into Europe and Africa, according to the team. Many samples from Africa and Asia were the key to the researchers approach.
Dogantzis says that they focused on getting samples from Africa and Asia because they are under-represented in studies of honeybee origins.
The team estimated that the A. mellifera ancestor started in Asia around 7 million years ago and spread to Africa and Europe around 6 million years ago.
Dogantzis says previous studies suggest African and European subspecies evolved in the last million years. She says that the focus of the studies was on when they appeared, whereas the new study focuses on where they spread from.
Asian honeybees scream in alarm when giant hornets attack the hive.
Even though the bees adapted to vastly different climates, a core set of around 145 genes had some kind of change in their sequence.
The small set of genes involved in western honeybee adaptation was a surprise, as the A. mellifera genome contains around 12,000 genes in total.
Dogantzis says that understanding the genes involved in adaptation to new environments might be useful. If it is ever necessary to genetically engineer honeybees to cope with climate change, it might provide targets.
Thousands of honeybees rear the brood, maintain the nest structure and collect food in colonies. The genes involved in bee adaptation were related to the behavior of the worker bees and not the queen bees, as was previously thought.
Natural selection acts on the workers to improve the fitness of their colonies even though they are not the reproductive members of the colony.
De la Ra says the study is conclusive with the hypothesis of Asian origin.
Science Advances has a journal reference.
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