Skip to main content
U.S. flag

An official website of the United States government

Genetic architecture and evolution of color variation in American black bears

December 16, 2022

Color variation is a frequent evolutionary substrate for camouflage in small mammals, but the underlying genetics and evolutionary forces that drive color variation in natural populations of large mammals are mostly unexplained. The American black bear, Ursus americanus (U. americanus), exhibits a range of colors including the cinnamon morph, which has a similar color to the brown bear, U. arctos, and is found at high frequency in the American southwest. Reflectance and chemical melanin measurements showed little distinction between U. arctos and cinnamon U. americanus individuals. We used a genome-wide association for hair color as a quantitative trait in 151 U. americanus individuals and identified a single major locus (p < 10−13). Additional genomic and functional studies identified a missense alteration (R153C) in Tyrosinase-related protein 1 (TYRP1) that likely affects binding of the zinc cofactor, impairs protein localization, and results in decreased pigment production. Population genetic analyses and demographic modeling indicated that the R153C variant arose 9.36 kya in a southwestern population where it likely provided a selective advantage, spreading both northwards and eastwards by gene flow. A different TYRP1 allele, R114C, contributes to the characteristic brown color of U. arctos but is not fixed across the range.

Citation Information

Publication Year 2023
Title Genetic architecture and evolution of color variation in American black bears
DOI 10.1016/j.cub.2022.11.042
Authors E. Puckett, I. S. Davis, D. C. Harper, K. Wakamatsu, G. Battu, J. L. Belant, D. E. Beyer, C. Carpenter, A. P. Crupi, M. Davidson, C. S. DePerno, N. Forman, N. L. Fowler, D. L. Garshelis, N. Gould, K. Gunther, Mark A. Haroldson, S. Ito, David. M Kocka, C. Lackey, R. Leahy, C. Lee-Roney, T. Lewis, A. Lutto, K. McGowan, C. Olfenbuttel, M. Orlando, A. Platt, M. D. Pollard, M. Ramaker, Heather Reich, Jaime L. Sajecki, S. K. Sell, J. Strules, S. Thompson, Frank T. van Manen, Craig Whitman, R. Williamson, F. Winslow, C. B. Kaelin, M. S. Marks, G. S. Barsh
Publication Type Article
Publication Subtype Journal Article
Series Title Current Biology
Index ID 70239011
Record Source USGS Publications Warehouse
USGS Organization Northern Rocky Mountain Science Center