Bees, both wild and farmed, are a wonderful and essential component of modern ecosystems and economies. But how did this useful little insect come to be? Today there are over 16,000 species of bees throughout the world, all of which originated from an ancestor in the distant past which has proliferated and spread throughout the world. What was this ancestor? Where did they spread from? And how have they shaped the world we know today?
Bees and Flowers: Best Friends from the Beginning
Like many pollinating insects, bees have their origins deeply connected to the evolution of flowering plants in the mid Cretaceous. Over 100 million years ago, flowering plants began to spread across the cretaceous world, toppling non-flowering plants as the most prevalent terrestrial plant species and opening up new opportunities for whatever organisms could utilize these new plants. One such organism was a carnivorous wasp-like insect that fed on pollen-eating insects that were emerging at the time. This new species began to adapt to use this new food source, directly eating pollen itself. However, these new pollen eaters were still solitary like most modern bee species, It wasn't until tens of millions of years later that the first eusocial bees (bees that live together in social systems with labour division) appeared.As flowering plants established themselves as the dominant terrestrial plants and their connection and interdependence with pollinators such as bees grew, the ancestor of modern bees began specializing in pollination as a lifestyle. Their diets developed to become dependent on the pollen and nectar of these plants and the pollination of specific plants. This coevolution (evolution resulting from complimentary pressures two closely-involved species place on each other) helped drive the diversification of both flowering plants and bees. Genetic evidence suggests that it was this coevolution with flowering plants that spurred the explosion of diversity of bees, which have remained diverse and prominent to this day.
Unlikely Cousins
Coming from a shared ancestral species, bees split off from wasps through their coevolution with flowering plants; their lifestyle shifting away from predation and parasitism to mutualism in the form of pollination. But, bees themselves wouldn't stay unified for long. The early wasp-like ancestor of bees, soon after differentiating from wasps, had ants differentiate from them. This new family of insects found a different way of life in its environment, doing away with only feeding on pollen and nectar, becoming entirely eusocial, and growing wings in only special circumstances. Bees and ants, despite their differences, are more closely related to each other than either of them are to wasps.
Where Did Honey Bees Come From?
There are seven species of honey bee found throughout the world, but only one, Apis mellifera, the European honey bee, is farmed and cultivated around the world. Its native range reaches from northwestern Africa, through Europe, and into western Asia. Within this area, dozens of subspecies exist. However, six more honey bee species are found throughout Africa, Europe, and Asia and thousands of non-honey bees around the world. This begs the question of where the common ancestor of these honey bees came from?
The current range of honey bees. (Obtained from https://en.wikipedia.org/wiki/Honey_bee)
Originally, it was thought that the ancestor of honey bees originated in Africa. However, as of 2014, new genetic evidence suggests that honey bees originated in Asia, where they then expanded and diversified to the rest of the world. The European honey bee we're all familiar with split from its cousin Apis ceranae, the Asian honey bee, only 6 to 9 million years ago in southeast Asia, where it then diverged into the 32 known subspecies today. Since being farmed, humans have spread these bees throughout the world.
The Marks of Coevolution
(Obtained from https://en.wikipedia.org/wiki/Ophrys_apifera)
The hundred twenty million year-long coevolution between flowering plants and bees can be seen to this day. Ophrys apifera, the bee orchid, is a flower found throughout the Mediterranean and surrounding area, reaching as north as Ireland. This orchid has evolved to look similar to a bee, and in its southern ranges solitary bees of the Eucera genus attempt to mate with the artificial bee, pollinating the flower in the process. However, in the northern ranges of the flower, self-pollination is almost exclusively used. Few bees attempt to mate with it. This has led some to suspect that in the past, another species of bee was the target of the orchids mimicry and since its disappearance the flower has been forced to adapt either to self-pollinate or to attract different bees.
The history of the honey bee is rich, with an explosion of variety following the spread of flowering plants and a close relationship with those plants to this day. Bees and flowers have driven each other to an enormous variety of thousands of organisms and through their pollination along with that of other pollinating species, enable the great variety of plants, fruits, and nuts we enjoy today. All thanks to insects in the age of dinosaurs forming a relationship with new plants that has stood the test of time.
If that isn't commitment, then I don't know what is.
Sources
- https://www.sciencedirect.com/science/article/pii/S0960982217301458- https://www.sciencedirect.com/science/article/pii/S096098221300256X
- https://www.sciencedirect.com/science/article/pii/S0960982213010567
- https://americanbeejournal.com/the-elusive-genesis-of-apis-mellifera/
- https://www.scientificamerican.com/article/the-beguiling-history-of-bees-excerpt/
- http://www.killowen.com/genetics14.html
- https://zoom-ology.com/2018/08/23/reproductive-mimicry-the-bee-orchid/
- https://en.wikipedia.org/wiki/Bee
- https://www.scientificamerican.com/article/the-beguiling-history-of-bees-excerpt/
- https://en.wikipedia.org/wiki/Honey_bee
- Scott B.
