Meeting Abstract
The idea that traits which increase fecundity necessarily trade off with other traits is a central tenet of life history theory. Previous work exploring these trade offs across species of mammals supports this idea, however, studies investigating relationships among life history traits (e.g., fecundity, longevity, and metabolic traits) does not always support these trade offs within species. We obtained data from the publicly available Mouse Phenome Database by the Jackson Laboratory to investigate correlations among life history traits and between life history and metabolic variables in adult female mice. We collapsed fitness-related variables in a principal component analysis, which resulted in two principal components (breeding frequency and reproductive strategy) that describe the variance in reproductive traits. Scores from this PCA were then regressed against measurements from other phenotypic traits (e.g., mass-specific metabolic traits, longevity, and body size). Although these strains are typically used in biomedical research models, we propose that data from lab mice can be used to identify patterns across life-history variables that could not otherwise be studied in wild rodents. Our findings support the ideas that 1) traits that increase reproductive performance do not always come at a cost to other life history traits, such as longevity, and 2) patterns of life history trait co-variation within species is not always consistent with predictions that are based on interspecific comparisons. Together, these findings outline the need to continue studying patterns within species, as they may differ from initial predictions.
