title: Group benefit associated with polymorphic trichromacy in a Malagasy primate (Propithecus verreauxi).
abstract: In some primate lineages, polymorphisms in the X-linked M/LWS opsin gene have produced intraspecific variation in color vision. In these species, heterozygous females exhibit trichromacy, while males and homozygous females exhibit dichromacy. The evolutionary persistence of these polymorphisms suggests that balancing selection maintains color vision variation, possibly through a 'trichromat advantage' in detecting yellow/orange/red foods against foliage. We identified genetic evidence of polymorphic trichromacy in a population of Verreaux's sifaka (Propithecus verreauxi) at Kirindy Mitea National Park in Madagascar, and explored effects of color vision on reproductive success and feeding behavior using nine years of morphological, demographic, and feeding data. We found that trichromats and dichromats residing in social groups with trichromats exhibit higher body mass indices than individuals in dichromat-only groups. Additionally, individuals in a trichromat social group devoted significantly more time to fruit feeding and had longer fruit feeding bouts than individuals in dichromat-only groups. We hypothesize that, due to small, cohesive sifaka social groups, a trichromat advantage in detecting productive fruit patches during the energetically stressful dry season also benefits dichromats in a trichromat's group. Our results offer the first support for the 'mutual benefit of association' hypothesis regarding the maintenance of polymorphic trichromacy in primates.
authors.affiliation: Department of Anthropology, University of Texas at Austin, 2201 Speedway Stop C3200, Austin, TX, 78712, USA.
authors.forename: Carrie C
authors.initials: CC
authors.lastname: Veilleux
authors.affiliation: Department of Anthropology, University of Texas at Austin, 2201 Speedway Stop C3200, Austin, TX, 78712, USA.
authors.forename: Clara J
authors.initials: CJ
authors.lastname: Scarry
authors.affiliation: Department of Anthropology, University of Texas at Austin, 2201 Speedway Stop C3200, Austin, TX, 78712, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Di Fiore
authors.affiliation: Department of Anthropology, University of Texas at Austin, 2201 Speedway Stop C3200, Austin, TX, 78712, USA.
authors.forename: E Christopher
authors.initials: EC
authors.lastname: Kirk
authors.affiliation: Department of Anthropology, University of Texas at Austin, 2201 Speedway Stop C3200, Austin, TX, 78712, USA.|Population Research Center, University of Texas at Austin, Austin, TX, 78712, USA.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Bolnick
authors.affiliation: Department of Anthropology, University of Texas at Austin, 2201 Speedway Stop C3200, Austin, TX, 78712, USA.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Lewis
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001835:Body Weight; D055253:Color Vision / Q000235:genetics*; D055358:Cone Opsins / Q000235:genetics* / Q000378:metabolism; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D015870:Gene Expression; D005838:Genotype; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008270:Madagascar; D008297:Male; D000068316:Parks, Recreational; D011110:Polymorphism, Genetic; D012621:Seasons; D011443:Strepsirhini / Q000502:physiology*
chemical_list: D055358:Cone Opsins