The origins of flowering plants and pollinators

For more than a century there has been a fascination with the surprisingly rapid rise and early diversity of flowering plants (angiosperms). Darwin described the seemingly explosive diversification of angiosperms as an “abominable mystery,” and debates continue about the origin and processes driving angiosperm speciation. Dating the origin of angiosperms was traditionally the prerogative of paleobotanists who read the fossil record of plants, but with DNA sequencing becoming increasingly sophisticated, molecular dating methods have come to the table. Many angiosperm fossils can be dated to the Early Cretaceous (∼135 million years ago), which has led paleobotanists to reason that they originated during that era. It is now increasingly recognized that angiosperms are probably older than the oldest fossils, but how much older remains controversial. When angiosperms originated is key to understanding the origin and evolution of pollinators, particularly insects such as bees, butterflies, moths, and flies.