title: Color vision varies more among populations than among species of live-bearing fish from South America.
abstract: BACKGROUND
  Sensory Bias models for the evolution of mate preference place a great emphasis on the role of sensory system variation in mate preferences. However, the extent to which sensory systems vary across- versus within-species remains largely unknown. Here we assessed whether color vision varies in natural locations where guppies (Poecilia reticulata) and their two closest relatives, Poecilia parae and Poecilia picta, occur in extreme sympatry and school together. All three species base mate preferences on male coloration but differ in the colors preferred.
  
  
  RESULTS
  Measuring opsin gene expression, we found that within sympatric locations these species have similar color vision and that color vision differed more across populations of conspecifics. In addition, all three species differ across populations in the frequency of the same opsin coding polymorphism that influences visual tuning.
  
  
  CONCLUSIONS
  Together, this shows sensory systems vary considerably across populations and supports the possibility that sensory system variation is involved in population divergence of mate preference.
authors.affiliation: Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, BC, Canada. bsandkam@sfu.ca.
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Sandkam
authors.affiliation: Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, BC, Canada. cmyoung@sfu.ca.
authors.forename: C Megan
authors.initials: CM
authors.lastname: Young
authors.affiliation: School of Interactive Arts and Technology, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, BC, Canada. francesbreden@gmail.com.
authors.forename: Frances Margaret Walker
authors.initials: FM
authors.lastname: Breden
authors.affiliation: Department of Biology, University of Missouri-St. Louis, 1 University Blvd., 103 Research Building, St. Louis, 63121, MO, USA. bourneg@umsl.edu.
authors.forename: Godfrey R
authors.initials: GR
authors.lastname: Bourne
authors.affiliation: Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, BC, Canada. breden@sfu.ca.
authors.forename: Felix
authors.initials: F
authors.lastname: Breden
mesh_terms: D000818:Animals; D005075:Biological Evolution; D055253:Color Vision; D005260:Female; D029941:Fish Proteins / Q000235:genetics; D005787:Gene Frequency; D008297:Male; D052586:Mating Preference, Animal; D055355:Opsins / Q000235:genetics; D011036:Poecilia / Q000145:classification* / Q000235:genetics* / Q000502:physiology; D011110:Polymorphism, Genetic; D013020:South America; D061350:Sympatry
chemical_list: D029941:Fish Proteins; D055355:Opsins