Does Behavior Evolve First? Correlated Responses to Selection for Voluntary Wheel-Running Behavior in House Mice

• DOI: 10.1086/730153
• Publication Date: 2024-02-22T20:12:42Z
• Authors: Rahim H. Khan; Justin S. Rhodes; Isabelle A. Girard; Nicole E. Schwartz; Theodore Garland
• Keywords: Wheel running; Turnover; House mice

How traits at multiple levels of biological organization evolve in a correlated fashion response to directional selection is poorly understood, but two popular models are the very general "behavior evolves first" (BEF) hypothesis and more specific "morphology-performance-behavior-fitness" (MPBF) paradigm. Both acknowledge that often acts relatively directly on behavior when evolves, other will as well most with some lag. However, this proposition exceedingly difficult test nature. Therefore, we studied responses high-runner (HR) mouse experiment, which four replicate lines have been bred for voluntary wheel-running compared nonselected control (C) lines. We analyzed wide range measured generations 20–24 (with focus new data from generation 22), coinciding point all HR were reaching limits (plateaus). Significance (226 P values) across trait types by ANOVA, used positive false discovery rate comparisons. This meta-analysis showed that, surprisingly, measures performance (including maximal oxygen consumption during forced exercise) no evidence having diverged between C lines, nor did any life history (e.g., litter size), whereas body mass had responded (decreased) least strongly wheel running. Overall, results suggest mice evolved primarily changes motivation rather than ability time they limits. In addition, neither BEF model MPBF hierarchical evolution provides particularly good fit experiment.