The rock pocket mouse, a species of rodents living in rocky habitats in adjacent deserts of Arizona, New Mexico, and Mexico. The genetic basis for adaptive melanism (q.v.) was first elucidated in this species. The color of the rodents matches their natural substrates, and so provides camouflage. The color of the dorsal fur is controlled by the MC1R gene (q.v.), and mutations at this locus determine the relative amounts of black vs. yellow melanin present in the hair. As predation eliminated mice with coat colors that failed to match their surroundings, genotypes were selected that provided the appropriate crypsis. See Classification, Chordata, Mammalia, Rodentia; Chronology, 2003, Nachman, Hoekstra, and D'Agostino; melanin.
Subjects: Genetics and Genomics.