Biologists have long believed that orchid bees and orchids rely on each other in equal measure. The shimmering bees pollinate orchids in return for the flowers’ donation of perfumes, which male bees use to attract females. And so it was thought that the two organisms co-evolved. But a study led by Santiago Ramírez, an evolutionary biologist at the University of California, Berkeley, that was published in Science in late 2011 revealed that the bees arose first, thus suggesting that the two are more independent than previously thought.
Ramírez’s work shows that although the orchids seem very adapted to the bees—having developed scents that bees like and mechanisms to deposit pollen onto the bees’ body—the insects are far less specialized. They collect scents from more than 700 species of plants, and they pollinate an array of them. “The bees and plants all interact,” Ramírez says, “and we know very little about how those networks of interactions evolve.”