LIFE × EVOLUTION

The Origin of Bees

~123 to 100 million years ago

Phanerozoic · Mesozoic · Cretaceous

Bees descend from predatory wasps that began to feed their larvae on pollen instead of insects, between 123 and 100 million years ago, in western Gondwana, a former southern continent, as the flowering plants spread.

Bees are insects that feed their larvae on pollen, a diet called pollinivory. They descend from predatory wasps, which fed their larvae on insects. Almeida and colleagues (2023) place the change of diet in western Gondwana, probably shortly before the South Atlantic Ocean opened. The eudicots appeared and diversified at the same time. The eudicots are the group that comprises three quarters of living flowering plant species. Bees and eudicots have remained associated ever since.

Why it matters

About a third of human food depends on pollination by animals, the transport of pollen from one flower to another, and most of that third depends on bees. Flowers and bees have evolved in relation to one another since the origin of bees, and neither can now be rapidly replaced.

Dating & uncertaintyDisputed

Molecular clocks, which date a lineage from the differences accumulated in DNA, place the origin of bees around 123 million years ago, within a range of 113 to 132 million years ago. The oldest bee fossils are considerably younger. Such a discrepancy between molecular clocks and fossils is usual. The age of the flowering plants is the other, older part of the same debate. Darwin called that question an abominable mystery, and it remains open.

Earth history as one day

23:20:5939 min 1 s before midnight

if Earth’s 4.54 billion years were compressed into a single day