Sexual dichromatism is decoupled from diversification over deep time in fishes

Elizabeth Christina Miller, Sarah L. Mesnick, John J. Wiens

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Sexually selected traits have long been thought to drive diversification, but support for this hypothesis has been persistently controversial. In fishes, sexually dimorphic coloration is associated with assortative mating and speciation among closely related species, as shown in classic studies. However, it is unclear whether these results can generalize to explain diversity patterns across ray-finned fishes, which contain the majority of vertebrate species and 96% of fishes. Here, we use phylogenetic approaches to test for an association between sexual dichromatism and diversification rates (speciation minus extinction) in ray-finned fishes. We assembled dichromatism data for 10,898 species, a data set of unprecedented size. We found no difference in diversification rates between monochromatic and dichromatic species when including all ray-finned fishes. However, at lower phylogenetic scales (within orders and families), some intermediate-sized clades did show an effect of dichromatism on diversification. Surprisingly, dichromatism could significantly increase or decrease diversification rates. Moreover, we found no effect in many of the clades initially used to link dichromatism to speciation in fishes (e.g., cichlids) or an effect only at shallow scales (within subclades). Overall, we show how the effects of dichromatism on diversification are highly variable in direction and restricted to certain clades and phylogenetic scales.

Original languageEnglish (US)
Pages (from-to)232-252
Number of pages21
JournalAmerican Naturalist
Issue number2
StatePublished - Aug 2021


  • Color
  • Diversification
  • Fishes
  • Phylogenetic scale
  • Sexual selection
  • Speciation

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics


Dive into the research topics of 'Sexual dichromatism is decoupled from diversification over deep time in fishes'. Together they form a unique fingerprint.

Cite this