On The Origin Of Domesticity: A Test Of Keeler’s “black-gene” Hypothesis

In a classic set of papers on psychogenetics published in the 1940s, Clyde Keeler hypothesized that a single black recessive coat-color gene in Norway rats (Rattus norvegicus) was linked to docile, sluggish behavior as well as to reduced brain and adrenal gland size. Discovery of a possible "black-gene" rat in a large population of wild brown Norway rats prompted this test of Keeler's proposed genetic origin of domesticity. Comparisons included computer-monitored open-field activity, activity wheel performance, water consumption, and physiological measures. Contrary to Keeler's hypothesis, essentially no differences were found among wild black rats, their offspring, and brown rats on either the behavioral or the physiological measures. Our data would suggest that multigenic mechanisms of domestication, including selections and ontogenetic processes, seem to account best for the origin of domesticity. © 1981, The Psychonomic Society, Inc.. All rights reserved.