Less is more: lemurs ( Eulemur spp.) may benefit from loss of trichromatic vision

摘要: Vertebrate color vision is an ideal system for studying the gains and losses of genetic variation across lineages impacts on behavior. Among placental mammals, trichromatic unique to primates argued be adaptive foraging reddish food. However, trichromacy variably present in lemurs, including species within cathemeral genus Eulemur, due inter- intra-specific X-linked opsin genes. Although this could result from drift, it also reflect ecological adaptation. To understand contributions variation, we examined cone genes 11 Eulemur species. We found that only E. flavifrons macaco have polymorphic trichromacy. Most dichromatic “M” (green-shifted) opsin; uniquely, one (E. rubriventer) has dichromacy based “L” (red-shifted) opsin. This latter appears represent loss a (M opsin) or ancestor. address potential explanations studied dietary behavior wild rubriventer collected reflectance spectra plant consumed. Visual models suggest should provide advantage detecting foods; however, luminance contrasts were greatest dichromats with L As are often active low-light rainforest conditions, cues may relatively important, which favor opsin, while leading relaxed selection on, against, The presence different alleles adaptations related diet, activity pattern, habitat. Loss thought maladaptive, can occur through natural selection. primates, some vision, ability distinguish greenish hues; others red-green colorblind (dichromatic). differences by lemurs (Eulemur)—a both day night. variable species, full was likely lost at least lineage. Foraging ecology indicates advantageous foods, but brightness more salient species’ vision. important than particularly night, lemurs.