Three days ago a new paper was published in PLOS ONE presenting the first evidence for a massive extinction event among bees near the K/T boundary (that is the boundary where non-avian dinosaurs, pterosaurs, etc went extinct). The paper is #openaccess and can be found here: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0076683
This is particularly interesting because of the evolutionary history of bees and flowering plants. The very first angiosperms (flowering plants in the technical sense) probably originated in the Late Jurassic or so. The first eudicot plants, the group of flowering plants that includes a large proportion of our food plants and ornamentals, probably arose in the mid-late Cretaceous. Bees, which are tightly associated with eudicot plants as symbiotes (particularly as pollinators) arose at a similar time. Because eudicot plants are thought to have taken a hit at the K/T boundary, it stands to reason that bees might as well.
The authors built a molecular phylogeny, calibrated against time (see below) for bees in the clade Xylocopinae. Their tree suggests a mid-Cretaceous origin for the group, and also that it diversified rapidly for a time, suddenly lagged, and then began splitting again after the K/T. This implies either a "long fuse" diversification event, or a major extinction event near the K/T boundary. The authors prefer the extinction event explanation, based on historical biogeography and specifics of their ecological diversity.
From the paper:
"Given the close relationship between eudicots and bees, one might expect that any extinction events affecting eudicots would also impact on bees and vice versa. Rapid and simultaneous extinctions in both bees and their host plants would have affected plant-pollinator dynamics in ways that could shape subsequent ecosystems in very important ways . For example, extinction of plant-specialist (oligolectic) bees would have impacted strongly on their dependent hosts, whereas loss of generalist (polylectic) bee pollinators would have had more diffuse effects , . In both cases, large reductions in the numbers of both eudicots and their pollinators would have introduced a strong stochastic element to how ecosystems subsequently reassembled."
Phil Windley is the Founder and Chief Technology Officer of Kynetx, an early stage company providing context automation services. He is also an Adjunct Professor of Computer Science at Brigham Young University where he teaches courses on reputation, digital identity, large-scale system design, and programming languages. Phil writes the popular Technometria blog and is a frequent contributor to various technical publications. He is also the author of the book Digital Identity from O'Reilly Media.
Prior to joining BYU, Phil spent two years as the Chief Information Officer (CIO) for the State of Utah, serving on Governor Mike Leavitt's Cabinet and as a member of his Senior Staff. Before entering public service, Phil was Vice President for Product Development and Operations at Excite@Home and Chief Technology Officer (CTO) of iMALL, Inc. an early creator of electronic commerce tools. Still active in business, Phil serves on the Boards of Directors and Advisory Boards for several high-tech companies. Phil received his Ph.D. in Computer Science from Univ. of California, Davis in 1990.
- Univ. of California, Davis & Univ. of IdahoComputer Science, 1986 - 1990