title: Monophyly and extensive extinction of advanced eusocial bees: insights from an unexpected Eocene diversity.
abstract: Advanced eusociality sometimes is given credit for the ecological success of termites, ants, some wasps, and some bees. Comprehensive study of bees fossilized in Baltic amber has revealed an unsuspected middle Eocene (ca. 45 million years ago) diversity of eusocial bee lineages. Advanced eusociality arose once in the bees with significant post-Eocene losses in diversity, leaving today only two advanced eusocial tribes comprising less than 2% of the total bee diversity, a trend analogous to that of hominid evolution. This pattern of changing diversity contradicts notions concerning the role of eusociality for evolutionary success in insects.
authors.affiliation: Division of Entomology, Natural History Museum and Biodiversity Research Center, 1460 Jayhawk Boulevard, University of Kansas, Lawrence, KS 66045-7523, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Engel
mesh_terms: D000818:Animals; D001516:Bees / Q000145:classification*; D005075:Biological Evolution; D005260:Female; D005580:Fossils; D010802:Phylogeny; D012919:Social Behavior