The Genetic and Evolutionary Drives behind Primate Color Vision

Abstract

Primate color vision is based on two to three cone types in the retina, each expressing a different class of visual pigment, making them the only mammals that possess trichromacy. These pigment classes are the short wavelength-sensitive (SWS1) pigment and the long wavelength-sensitive (LWS) pigment, orthologues of the same pigments found in many other vertebrates, as well as the middle wavelength-sensitive (MWS) pigment, a paralogue to the LWS pigment. Trichromacy was achieved differently in Old World and New World primates. In Old World primates, a duplication of the LWS opsin gene occurred giving rise to a "red-sensitive" or L pigment and a "green-sensitive" or M pigment. Their corresponding L and M genes are adjacent on the X chromosome which, together with their high sequence homology, is the underlying cause for the high frequency of red-green color blindness seen in humans. In New World primates and prosimians, however, the mechanism leading to trichromacy, with one exception, is based on a single polymorphic LWS gene, from which different allelic variants encode pigments with differing spectral peaks. X chromosome inactivation limits expression to just one gene per photoreceptor meaning that trichromacy is only seen in females; while all male are red-green color blind. Despite several leading hypotheses, the reasons for the different evolutionary paths taken by Old and New World primates for trichromacy are still unclear and remain to be confirmed.

Colour vision variation in leaf‐nosed bats (Phyllostomidae): Links to cave roosting and dietary specialization

“…These selective constraints may be lost among species roosting in darker habitats, and independent pseudogenization of OPN1SW in several cave‐roosting bats in the family Pteropodidae (Yinpterochiroptera) has been documented (Zhao, Rossiter, et al., ). Colour vision may also be more staunchly maintained by species foraging for fruit and nectar, for which colour cues may be more relevant to target detection and selection (Reviewed in Carvalho, Pessoa, Mountford, Davies, & Hunt, ), than for species that prey on insects, a task for which echolocation and visual acuity may be more important. Here, we seek to shed new light on the associations between species‐specific ecology and the tuning and functionality of opsin genes underlying colour vision in the highly diverse radiation of leaf‐nosed bats.…”

Phylogenetic analyses suggest independent origins for trichromatic color vision in apes and Old World monkeys

“…On the other hand, some authors mention that it is possible the literature has underestimated the number of prosimian species with allelic trichromatic vision because many studies have been restricted to small cohorts of animals 9 . Among New World monkeys, we found four alleles, two with a maximum wavelength of absorption in the red range (560 and 553 nm), one with a medium wavelength of absorption in the green range (537 nm), and another in an intermediate range of absorbance (543 nm).…”

The Diversity and Adaptive Evolution of Visual Photopigments in Reptiles

“…These results support the hypothesis that the modern gecko ancestor was a diurnal lizard lacking rod opsin (Röll, 2000) and that SWS2 photopigments were subsequently lost as an adaptation to primarily nocturnal activities (Yokoyama and Blow, 2001). However, it should be noted that, although mostly nocturnal, many species of the family Gekkonidae possess cone-like photopigments and UV-sensitive photoreceptors (Loew, 1994;Loew et al, 1996;Yokoyama and Blow, 2001), a photoreceptor class that is sometimes lost in nocturnal vertebrates (Carvalho et al, 2006(Carvalho et al, , 2017.…”