page_title: Bee
section_title: Evolution
hierarchical_section_title: Bee / Evolution
caption_attribution_description: English: It is the oldest bee found, was discovered in 2006
context_page_description: Bees are flying insects closely related to wasps and ants, known for their role in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfamily Apoidea. They are presently considered a clade, called Anthophila. There are over 16,000 known species of bees in seven recognized biological families. Some species — including honey bees, bumblebees, and stingless bees — live socially in colonies while some species — including mason bees, carpenter bees, leafcutter bees, and sweat bees — are solitary.
  Bees are found on every continent except for Antarctica, in every habitat on the planet that contains insect-pollinated flowering plants. The most common bees in the Northern Hemisphere are the Halictidae, or sweat bees, but they are small and often mistaken for wasps or flies. Bees range in size from tiny stingless bee species, whose workers are less than 2 millimetres long, to Megachile pluto, the largest species of leafcutter bee, whose females can attain a length of 39 millimetres.
context_section_description: The ancestors of bees were wasps in the family Crabronidae, which were predators of other insects. The switch from insect prey to pollen may have resulted from the consumption of prey insects which were flower visitors and were partially covered with pollen when they were fed to the wasp larvae. This same evolutionary scenario may have occurred within the vespoid wasps, where the pollen wasps evolved from predatory ancestors. Until recently, the oldest non-compression bee fossil had been found in New Jersey amber, Cretotrigona prisca of Cretaceous age, a corbiculate bee. A bee fossil from the early Cretaceous (~100 mya), Melittosphex burmensis, is considered "an extinct lineage of pollen-collecting Apoidea sister to the modern bees". Derived features of its morphology (apomorphies) place it clearly within the bees, but it retains two unmodified ancestral traits (plesiomorphies) of the legs (two mid-tibial spurs, and a slender hind basitarsus), showing its transitional status. By the Eocene (~45 mya) there was already considerable diversity among eusocial bee lineages.
  The highly eusocial corbiculate Apidae appeared roughly 87 Mya, and the Allodapini (within the Apidae) around 53 Mya.
  The Colletidae appear as fossils only from the late Oligocene (~25 Mya) to early Miocene.
  The Melittidae are known from Palaeomacropis eocenicus in the Early Eocene.
  The Megachilidae are known from trace fossils (characteristic leaf cuttings) from the Middle Eocene.
  The Andrenidae are known from the Eocene-Oligocene boundary, around 34 Mya, of the Florissant shale.
  The Halictidae first appear in the Early Eocene with species found in amber. The Stenotritidae are known from fossil brood cells of Pleistocene age.
caption: Melittosphex burmensis, a fossil bee preserved in amber from the Early Cretaceous (100 to 145 million years ago) of Myanmar
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