Assertion: lemur's vision | /r/AtLocation | the red ruffed lemur
Facets:
value: due to polymorphism in opsin genes
type: CAUSE
value: rarely
type: DEGREE
Source sentences:
text: Due to polymorphism in opsin genes, which code for color receptivity, trichromatic vision may rarely occur in females of a few lemur species, such as Coquerel's sifaka (Propithecus coquereli) and the red ruffed lemur (Varecia rubra).