Bees evolved from predatory wasps roughly 120 to 130 million years ago, during the Cretaceous period, when flowering plants were just beginning to spread across the Earth. The transition happened when certain small wasps that hunted insects on flowers gradually shifted to eating pollen instead. Today there are over 20,000 known bee species worldwide, but they all trace back to that single evolutionary shift from predator to pollinator.
Bees Descended From Tiny Predatory Wasps
The closest living relatives of bees are a group of small wasps in the family Ammoplanidae. These wasps hunt thrips, which are tiny insects that cluster on flowers and feed on pollen. That detail matters because it explains how the leap from meat-eater to pollen-eater could have happened. The ancestral wasp was already spending time on flowers, already surrounded by pollen, and already carrying pollen-dusted prey back to its nest. A 2018 genomic study published in the journal Current Biology confirmed Ammoplanidae as the sister group of all bees, giving researchers the clearest picture yet of what the “proto-bee” looked like and how it lived.
The proposed sequence goes like this: a small wasp hunted thrips on flowers, using visual and scent cues from the blooms to find prey. The thrips it carried back to its larvae were coated in pollen, so the larvae were already consuming pollen along with their insect meals. Over time, pollen became a more reliable food source than the thrips themselves. Adults likely began eating pollen and nectar for their own energy first, then eventually started regurgitating pollen back at the nest to feed their young directly. That shift from hunting insects to collecting pollen is the single most important innovation in bee evolution, and it set the stage for an explosion of new species.
The Oldest Bee Fossil
The oldest known bee fossil is Melittosphex burmensis, preserved in amber from Myanmar and dated to approximately 100 million years ago. It’s a tiny specimen, and it looks like something caught halfway between a wasp and a bee. It has branched (feathery) hairs, which is a hallmark of pollen-collecting insects, but it also retains several wasp-like features in its body structure. Paleontologists consider it a transitional form, physical proof that the wasp-to-bee shift was already underway in the middle of the Cretaceous.
This fossil appeared roughly 20 million years after the earliest flowering plants with true petals (eudicots) evolved, around 120 million years ago. Molecular clock estimates, which use DNA differences to calculate when lineages split, place the common ancestor of all living bees at about 123 million years ago. That lines up neatly: bees arose alongside the first big expansion of the flowers they would come to depend on.
Flowering Plants Drove Bee Diversity
The relationship between bees and flowering plants is one of the most consequential partnerships in the history of life on Earth. Eudicots, the group that includes roses, sunflowers, legumes, and about 75% of all flowering plant species, began diversifying around the same time bees appeared. As flowers evolved more shapes, colors, and nectar rewards to attract pollinators, bees evolved more specialized body plans and behaviors to exploit them. This feedback loop pushed both groups into rapid diversification.
A 2024 study in Nature Communications analyzed the insect fossil record and found that flowering plants played a dual role over time. During the Cretaceous, as angiosperms replaced conifers and other older plant groups, they helped buffer insect pollinators against extinction. Then, after about 50 million years ago, the growing diversity of flowering plants actively promoted the origination of new pollinator lineages. Bees diversified faster than their closest wasp relatives, and researchers attribute much of that speed to the switch to a vegetarian lifestyle, which opened up an enormous and expanding food source that predatory wasps couldn’t access.
All major bee families were likely present before the mass extinction event 66 million years ago that killed the dinosaurs. Bees survived that catastrophe and continued diversifying into the Cenozoic, the era we still live in.
Most Bees Are Solitary, Not Social
When most people picture bees, they think of honeybee hives or bumblebee colonies. But the vast majority of the world’s 20,000-plus bee species are solitary. A single female digs a small nest in the ground or in wood, provisions it with pollen, lays her eggs, and leaves. There’s no queen, no workers, no hive.
Complex social behavior, where a queen reproduces and sterile workers maintain the colony, evolved independently several times across the bee family tree. The earliest known origin of this kind of sociality dates to about 87 million years ago in the corbiculate bees, the group that includes honeybees, bumblebees, and stingless bees. Other bee lineages developed social living much later, some as recently as 20 million years ago. The repeated, independent evolution of social colonies suggests that something about bee biology, likely the habit of building and provisioning nests, made the transition to group living possible under the right conditions.
Where Honeybees Specifically Come From
The Western honeybee, Apis mellifera, is the species most people mean when they say “bee.” Its native range spans Europe, Africa, and the Middle East. There are ten species in the genus Apis, and the other nine are all found exclusively in Asia. That geographic pattern suggests the honeybee lineage originally emerged in Asia, then the ancestor of A. mellifera expanded westward into Europe and Africa, likely through two separate colonization routes. Western and eastern European honeybee populations are genetically distinct enough to suggest they arrived via different paths, possibly one through the Middle East and another through a more western corridor.
Honeybees are not native to the Americas, Australia, or most of the Pacific. European colonists brought the first honeybees to what is now the United States in 1622, when they were shipped to the Jamestown colony in Virginia. The subspecies they carried was the “dark bee” of Northern Europe. Over the following centuries, beekeepers introduced additional subspecies, including Italian and Carniolan bees, which are now the most common managed honeybees in North America. Before 1622, the continent’s pollination was handled entirely by its roughly 4,000 native bee species, most of them solitary ground-nesters and wood-nesters that still do the bulk of wild pollination today.
How the Shift to Pollen Changed Everything
The ability to collect and transport pollen was the key innovation that separated bees from their wasp ancestors. Early bees likely swallowed pollen and carried it internally, regurgitating it at the nest. Over millions of years, different bee lineages evolved external pollen-carrying structures: the dense “pollen baskets” on the hind legs of honeybees and bumblebees, the abdominal hair brushes of leafcutter bees, the leg brushes of mining bees. These structures evolved independently in different families, reflecting how central pollen transport is to bee survival.
Pollen is rich in protein and fat, which makes it a complete food for developing larvae. Nectar provides sugar for adult energy. Together, these plant-based resources gave bees access to a food supply that was abundant, widespread, and renewable, unlike the insect prey their wasp ancestors had to chase down individually. That dietary shift is likely the main reason bees diversified into over 20,000 species while their closest wasp relatives remained a comparatively small group. Flowers needed pollinators, bees needed flowers, and the result was one of evolution’s most productive partnerships.