title: Macroevolution of perfume signalling in orchid bees.
abstract: Theory predicts that both stabilising selection and diversifying selection jointly contribute to the evolution of sexual signalling traits by (1) maintaining the integrity of communication signals within species and (2) promoting the diversification of traits among lineages. However, for many important signalling traits, little is known about whether these dynamics translate into predictable macroevolutionary signatures. Here, we test for macroevolutionary patterns consistent with sexual signalling theory in the perfume signals of neotropical orchid bees, a group well studied for their chemical sexual communication. Our results revealed both high species-specificity and elevated rates of evolution in perfume signals compared to nonsignalling traits. Perfume complexity was correlated with the number of congeners in a species' range, suggesting that perfume evolution may be tied to the remarkably high number of orchid bee species coexisting together in some neotropical communities. Finally, sister-pair comparisons were consistent with both rapid divergence at speciation and character displacement upon secondary contact. Together, our results provide new insight into the macroevolution of sexual signalling in insects.
authors: Center for Population Biology, University of California, Davis, CA, 95616, USA. mgweber@ucdavis.edu.
authors: Marjorie G
authors: MG
authors: Weber
authors: Department of Animal Ecology, Evolution and Biodiversity, University of Bochum, 44780, Bochum, Germany.
authors: Lukasz
authors: L
authors: Mitko
authors: Department of Animal Ecology, Evolution and Biodiversity, University of Bochum, 44780, Bochum, Germany.
authors: Thomas
authors: T
authors: Eltz
authors: Center for Population Biology, University of California, Davis, CA, 95616, USA. sanram@ucdavis.edu.|Department of Evolution and Ecology, University of California, Davis, CA, 95616, USA. sanram@ucdavis.edu.
authors: Santiago R
authors: SR
authors: Ramírez
mesh_terms: D000819:Animal Communication; D000818:Animals; D001516:Bees / Q000235:genetics* / Q000502:physiology*; D005075:Biological Evolution; D008297:Male; D010675:Pheromones / Q000737:chemistry / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013045:Species Specificity
chemical_list: D010675:Pheromones
keywords: 
  Euglossa
  ; Chemical communication; coexistence; macroevolution; orchid bees; sexual selection; sexual signalling; species recognition