Welcome to the home page for the High Runner mouse selection experiment.

Please navigate pages with the three horizontal bars at your top left.

The Garland Lab webpage is here.

Bar race chart for Females across the first 31 generations.  These are the same data as shown in the graph below.

Bar race chart for Males across the first 31 generations.  Note the large seasonal fluctuations!  Also, note that males always run less than females.

This artificial selection experiment began in 1993 at the University of Wisconsin-Madison, and was transferred to the University of California, Riverside in 2001, after 31 generations of selective breeding.  Theodore Garland, Jr. is the Principal Investigator.

All of the publications resulting from this experiment can be found here.  The purpose of this web site, supported by a grant from the National Science Foundation, is to make the findings of the overall experiment accessible to both the general public and a scientific audience.

The overall goal of this experiment were to elucidate how complex traits evolve at multiple levels of organization, ranging from behavior to DNA sequences.  We also wanted to test the long-standing hypothesis that behavior tends to evolve more rapidly and prior to changes in underlying physiological capacities, a.k.a., the "behavior evolves first" hypothesis.  More specifically, we hypothesized that voluntary wheel-running behavior would evolve initially without any changes in aerobic capacities (VO2max).  After some generations, however, aerobic capacities would have to increase to allow continued response to selection for increased activity.  This was not a foregone conclusion, as physiology might have changed immediately with selection on behavior.

To begin the experiment, 224 mice of the outbred (not inbred!), genetically variable Hsd:ICR strain were purchased from Harlan Sprague Dawley in 1993.  These founder mice were designated generation -2.  The generation -2 mice were randomly paired and their offspring were generation -1.  The generation -1 mice were again randomly paired and their offspring were then randomly assigned to one of 8 lines, 4 of which would be selectively bred High Runner (HR) lines and four of which would be non-selected Control (C) lines.

Each generation, as sexually mature young adults, mice are given access to wheels attached to ordinary home cages for 6 days.  Food and water are available ad libitum.  The number of revolutions on days 5 and 6 is used as the selection criterion.  The highest-running male and female from within each of 10 families in a given HR line are chosen as breeders (within-family selection), then  paired with mice from other families in the same line.  In the non-selected Control lines, a male and female from each family are chosen without regard to how much they run.

The experiment has now surpassed 105 generations and well more than 160 publications have resulted.

GenBioPAC: Genetic and Biological factors that regulate Physical Activity Consortium

For more information, please contact the Principal Investigator:

Theodore Garland, Jr., Distinguished Professor, Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside.  Riverside, CA 92521, USA   tgarland@ucr.edu   Phone: 951-827-3524