title: Rapid diversification of sexual signals in Hawaiian Nesosydne planthoppers (Hemiptera: Delphacidae): the relative role of neutral and selective forces.
abstract: Changes in sexual signals have the potential to promote rapid divergence and reproductive isolation among populations of animals. Thus, identifying processes contributing to variation in signals is key to understanding the drivers of speciation. However, it is difficult to identify the processes initiating changes in signals in empirical systems because (1) the demographic history of populations under study is usually unclear, and (2) there is no unified hypothesis-testing framework for evaluating the simultaneous contribution of multiple processes. A unique system for study in the Hawaiian Islands, the planthopper species Nesosydne chambersi, offers a clear demographic context to disentangle these factors. By measuring variation in male vibratory sexual signals across different genetic populations on the island of Hawaii, we found that that multiple signal traits varied significantly between populations. We developed a mixed modelling framework to simultaneously test competing hypotheses about which processes contribute to changes in signal traits: genetic drift, sensory drive or reproductive character displacement. Our findings suggest that signal divergence proceeds along different axes for different signal traits under the influence of both neutral and selective processes. They are the first, to our knowledge, to document the relative importance of multiple processes on divergence in sexual signals.
authors.affiliation: Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, USA.
authors.forename: K R
authors.initials: KR
authors.lastname: Goodman
authors.forename: J P
authors.initials: JP
authors.lastname: Kelley
authors.forename: S C
authors.initials: SC
authors.lastname: Welter
authors.forename: G K
authors.initials: GK
authors.lastname: Roderick
authors.forename: D O
authors.initials: DO
authors.lastname: Elias
mesh_terms: D000819:Animal Communication; D000818:Animals; D005260:Female; D006430:Hemiptera / Q000235:genetics / Q000502:physiology*; D008297:Male; D012641:Selection, Genetic; D012726:Sexual Behavior, Animal / Q000502:physiology*
keywords: genetic drift; reproductive character displacement; sensory drive; sexual selection; signal evolution; speciation